DS26556_07 [MAXIM]

4-Port Cell/Packet Over T1/E1/J1 Transceiver; 4端口单元/包过T1 / E1 / J1收发器
DS26556_07
型号: DS26556_07
厂家: MAXIM INTEGRATED PRODUCTS    MAXIM INTEGRATED PRODUCTS
描述:

4-Port Cell/Packet Over T1/E1/J1 Transceiver
4端口单元/包过T1 / E1 / J1收发器

文件: 总368页 (文件大小:2038K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
DS26556  
4-Port Cell/Packet Over T1/E1/J1  
Transceiver  
www.maxim-ic.com  
GENERAL DESCRIPTION  
FEATURES  
The DS26556 is a quad, software-selectable T1,  
E1, or J1 transceiver with a cell/packet/TDM  
interface. It is composed of four framer/formatters  
+ LIUs, and a UTOPIA (cell), POS-PHY™  
(packet), and TDM backplane interface. Each  
framer has an HDLC controller that can be  
Four Independent, Full-Featured T1/E1/J1  
Transceivers  
UTOPIA 2 and 3 Cell Interface  
POS-PHY 2 and 3 Packet Interface  
mapped to any DS0 or FDL (T1)/Sa (E1) bit. The TDM Backplane Supports TDM Bus Rates  
DS26556 also includes full-featured BERT  
devices per port, and an internal clock adapter  
useful for creating synchronous, high-frequency  
backplane timing. The DS26556 is controlled  
through an 8-bit parallel port that can be  
configured for nonmultiplexed Intel or Motorola  
operation.  
from 1.544MHz to 16.384MHz  
Alarm Detection and Insertion  
Full-Featured BERT for Each Port  
AMI, B8ZS, HDB3, NRZ Line Coding  
Transmit Synchronizer  
BOC Message Controller (T1)  
One HDLC Controller per Framer  
Performance Monitor Counters  
RAI-CI and AIS-CI Support  
APPLICATIONS  
Routers  
IMA  
Add-Drop Multiplexers  
DSLAMs  
ATM  
WAN Interface  
PBXs  
Customer-Premise  
Equipment  
Internal Clock Generator (CLAD) Supplies  
16.384MHz, 8.192MHz, 4.096MHz, or  
2.048MHz  
Switches  
Central Office  
Equipment  
JTAG Test Port  
Single 3.3V Supply with 5V Tolerant Inputs  
POS-PHY and POS-PHY Level 3 are trademarks of PMC-Sierra, Inc.  
17mm x 17mm, 256-Pin BGA (1.00mm  
Pitch)  
ORDERING INFORMATION  
PIN-  
PACKAGE  
PART  
TEMP RANGE  
DS26556  
0°C to +70°C  
256 BGA  
DS26556N  
-40°C to +85°C  
256 BGA  
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device  
may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.  
1
REV: 090407  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
TABLE OF CONTENTS  
1
2
BLOCK DIAGRAMS  
FEATURES  
9
10  
2.1 FRAMER/LIU................................................................................................................................................10  
2.1.1  
2.1.2  
2.1.3  
2.1.4  
2.1.5  
Framer/Formatter................................................................................................................................................10  
Line Interface (LIU) .............................................................................................................................................10  
Clock Synthesizer ...............................................................................................................................................11  
HDLC Controllers................................................................................................................................................11  
Test and Diagnostics...........................................................................................................................................11  
2.2 CELL/PACKET INTERFACE .............................................................................................................................11  
2.2.1  
2.2.2  
2.2.3  
General ...............................................................................................................................................................11  
ATM ....................................................................................................................................................................12  
HDLC ..................................................................................................................................................................12  
2.3 CONTROL PORT ...........................................................................................................................................12  
3
4
5
BACKPLANE CONFIGURATION SCENERIOS  
ACRONYMS AND GLOSSARY  
PIN DESCRIPTIONS  
15  
19  
20  
5.1 SHORT PIN LIST ...........................................................................................................................................20  
5.2 DETAILED PIN LIST .......................................................................................................................................23  
6
7
DEVICE CONFIGURATION  
FUNCTIONAL PIN TIMING  
31  
32  
7.1 RECEIVER FUNCTIONAL TIMING DIAGRAMS ....................................................................................................32  
7.2 TRANSMITTER FUNCTIONAL TIMING DIAGRAMS...............................................................................................33  
7.3 UTOPIA/POS-PHY/SPI-3 SYSTEM INTERFACE FUNCTIONAL TIMING.............................................................35  
7.3.1  
7.3.2  
7.3.3  
7.3.4  
UTOPIA Level 2 Functional Timing.....................................................................................................................35  
UTOPIA Level 3 Functional Timing.....................................................................................................................39  
POS-PHY Level 2 Functional Timing ..................................................................................................................43  
POS-PHY Level 3 Functional Timing ..................................................................................................................47  
8
FUNCTIONAL DESCRIPTION  
49  
8.1 CELL / PACKET INTERFACE DESCRIPTION ......................................................................................................49  
8.1.1  
8.1.2  
Reset Descriptions..............................................................................................................................................49  
BIT / BYTE Ordering...........................................................................................................................................49  
8.2 UTOPIA/POS-PHY/SPI-3 SYSTEM INTERFACE............................................................................................49  
8.2.1  
8.2.2  
8.2.6  
General Description ............................................................................................................................................49  
Features..............................................................................................................................................................50  
System Interface Bus Controller .........................................................................................................................50  
8.3 ATM CELL / HDLC PACKET PROCESSING.....................................................................................................54  
8.3.1  
8.3.2  
8.3.3  
8.3.4  
8.3.5  
8.3.6  
8.3.7  
8.3.8  
General Description ............................................................................................................................................54  
Features..............................................................................................................................................................54  
Transmit Cell/Packet Processor..........................................................................................................................55  
Receive Cell/Packet Processor...........................................................................................................................55  
Cell Processor.....................................................................................................................................................56  
Packet Processor................................................................................................................................................61  
FIFO....................................................................................................................................................................63  
System Loopback................................................................................................................................................64  
8.4 T1 RECEIVE FRAMER DESCRIPTION AND OPERATION .....................................................................................65  
8.4.1  
8.4.2  
8.4.3  
8.4.4  
8.4.5  
8.4.6  
8.4.7  
8.4.8  
8.4.9  
T1 Loopbacks .....................................................................................................................................................65  
H.100 (CT Bus) Compatibility..............................................................................................................................66  
T1 Receive Status and Information.....................................................................................................................67  
Receive AIS-CI and RAI-CI Detection.................................................................................................................69  
T1 Receive-Side Digital Milliwatt Code Generation.............................................................................................69  
T1 Error Count Registers ....................................................................................................................................69  
T1 Receive Signaling Operation..........................................................................................................................70  
Software Signaling..............................................................................................................................................70  
Hardware Signaling.............................................................................................................................................70  
8.4.10 Signaling Re-insertion.........................................................................................................................................70  
8.4.11 Receive Signaling Freeze ...................................................................................................................................71  
8.4.12 Fractional T1 Support (Gapped-Clock Mode) .....................................................................................................71  
8.4.13 T1 Bit-Oriented Code (BOC) Controller...............................................................................................................71  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
8.4.14 Receive SLC-96 Operation .................................................................................................................................71  
8.4.15 Receive FDL .......................................................................................................................................................71  
8.4.16 Programmable In-Band Loop-Code Detection ....................................................................................................72  
8.4.17 Receive HDLC Controller....................................................................................................................................72  
8.4.18 Receive HDLC Controller Example.....................................................................................................................73  
8.5  
T1 TRANSMIT FORMATTER DESCRIPTION AND OPERATION .............................................................................74  
8.5.1  
T1 Per-Channel Loopback ..................................................................................................................................74  
T1 Transmit DS0 Monitoring Function.................................................................................................................74  
T1 Transmit Signaling Operation.........................................................................................................................74  
T1 Transmit Per-Channel Idle Code Insertion.....................................................................................................75  
T1 Transmit Channel Mark Registers..................................................................................................................75  
Fractional T1 Support (Gapped Clock Mode)......................................................................................................75  
T1 Transmit Bit Oriented Code (BOC) Controller................................................................................................75  
T1 Transmit FDL.................................................................................................................................................75  
Transmit SLC–96 Operation ...............................................................................................................................76  
8.5.2  
8.5.3  
8.5.4  
8.5.5  
8.5.6  
8.5.7  
8.5.8  
8.5.9  
8.5.10 Transmit HDLC Controller...................................................................................................................................76  
8.5.11 HDLC Transmit Example ....................................................................................................................................76  
8.5.12 Programmable In-Band Loop-Code Generator ...................................................................................................77  
8.5.13 Interfacing the T1 Tx Formatter to the BERT ......................................................................................................78  
8.5.14 T1 Transmit Synchronizer ...................................................................................................................................78  
8.6 E1 RECEIVE FRAMER DESCRIPTION AND OPERATION.....................................................................................78  
8.6.1  
8.6.2  
8.6.3  
8.6.4  
8.6.5  
8.6.6  
8.6.7  
8.6.8  
8.6.9  
H.100 (CT Bus) Compatibility..............................................................................................................................78  
E1 Error Count Registers....................................................................................................................................79  
DS0 Monitoring Function.....................................................................................................................................80  
E1 Receive Signaling Operation .........................................................................................................................80  
Fractional E1 Support (Gapped Clock Mode) .....................................................................................................81  
Additional Sa-Bit and Si-Bit Receive Operation (E1 Mode).................................................................................81  
HDLC Overhead Control Receive Example ........................................................................................................81  
Interfacing the E1 Rx Framer to the BERT..........................................................................................................82  
E1 Transmit Formatter Description and Operation..............................................................................................83  
8.6.10 Automatic Alarm Generation...............................................................................................................................83  
8.6.11 G.706 Intermediate CRC-4 Updating (E1 Mode Only) ........................................................................................83  
8.6.12 E1 Transmit DS0 Monitoring Function ................................................................................................................84  
8.6.13 E1 Transmit Signaling Operation ........................................................................................................................84  
8.6.14 Fractional E1 Support (Gapped Clock Mode) .....................................................................................................85  
8.6.15 Additional (Sa) and International (Si) Bit Operation (E1 Mode)...........................................................................85  
8.6.16 E1 Transmit HDLC Controller .............................................................................................................................85  
8.6.17 E1 HDLC Transmit Example...............................................................................................................................87  
8.6.18 Interfacing the E1 Transmitter to the BERT ........................................................................................................88  
8.6.19 E1 Transmit Synchronizer...................................................................................................................................88  
9
LINE INTERFACE UNIT (LIU)  
89  
9.1 LIU TRANSMITTER........................................................................................................................................89  
9.1.1 Pulse Shapes ...................................................................................................................................................89  
9.1.2 Transmit Termination ......................................................................................................................................89  
9.1.3 Power-Down and High-Z ................................................................................................................................89  
9.1.4 Transmit All Ones ............................................................................................................................................89  
9.1.5 Driver Fail Monitor ...........................................................................................................................................89  
9.2 RECEIVER ....................................................................................................................................................92  
9.2.1 Receiver Monitor Mode...................................................................................................................................92  
9.2.2 Peak Detector and Slicer................................................................................................................................93  
9.2.3 Clock and Data Recovery...............................................................................................................................93  
9.2.4 Receive Level Indicator ..................................................................................................................................93  
9.2.5 Loss of Signal...................................................................................................................................................93  
9.3 JITTER ATTENUATOR ....................................................................................................................................96  
9.4 LIU LOOPBACKS...........................................................................................................................................96  
9.4.1  
9.4.2  
9.4.3  
Analog Loopback ................................................................................................................................................96  
Local Loopback...................................................................................................................................................97  
Remote Loopback...............................................................................................................................................97  
10 OVERALL REGISTER MAP  
98  
11 REGISTER MAPS AND DESCRIPTIONS  
100  
11.1 GLOBAL REGISTERS ...................................................................................................................................100  
11.1.1 Global Control Registers...................................................................................................................................100  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.1.2 Global Status Registers ....................................................................................................................................107  
11.2 CELL / PACKET REGISTER DESCRIPTIONS....................................................................................................113  
11.2.1 General Cell / Packet Registers........................................................................................................................114  
11.2.2 Cell/Packet Status Registers.............................................................................................................................116  
11.2.3 Transmit FIFO Registers...................................................................................................................................118  
11.2.4 Transmit Cell Processor Registers....................................................................................................................123  
11.2.5 Transmit Packet Processor Registers...............................................................................................................130  
11.2.6 Receive Cell Processor Registers.....................................................................................................................136  
11.2.7 Receive Packet Processor Registers................................................................................................................151  
11.2.8 Receive FIFO Registers....................................................................................................................................163  
11.3 SYSTEM INTERFACE REGISTERS..................................................................................................................166  
11.3.1 Transmit System Interface Registers ................................................................................................................166  
11.3.2 Receive System Interface Registers .................................................................................................................168  
11.4 RECEIVE T1 FRAMER REGISTERS ...............................................................................................................171  
11.4.1 Receive Master-Mode Register.........................................................................................................................174  
11.4.2 Interrupt Information Register ...........................................................................................................................175  
11.4.3 T1 Receive Control Registers ...........................................................................................................................176  
11.4.4 T1 Line-Code Violation Count Register (LCVCR) .............................................................................................193  
11.4.5 T1 Path-Code Violation Count Register (PCVCR) ............................................................................................194  
11.4.6 T1 Frames Out-of-Sync Count Register (FOSCR)............................................................................................195  
11.4.7 DS0 Monitoring Function...................................................................................................................................196  
11.4.8 Receive Signaling Registers .............................................................................................................................197  
11.4.9 T1 Receive Per-Channel Idle Code Insertion....................................................................................................200  
11.4.10 T1 Receive Channel Mark Registers.................................................................................................................201  
11.4.11 Receive Fractional T1 Support (Gapped-Clock Mode)......................................................................................202  
11.4.12 Receive T1 Bit-Oriented Code (BOC) Controller...............................................................................................203  
11.4.13 Receive SLC-96 Operation ...............................................................................................................................204  
11.4.14 Receive FDL .....................................................................................................................................................205  
11.4.15 Programmable In-Band Loop-Code Detection ..................................................................................................206  
11.4.16 Receive HDLC Controller..................................................................................................................................212  
11.4.17 Receive BERT ..................................................................................................................................................218  
11.5 T1 TRANSMIT FRAMER................................................................................................................................220  
11.5.1 Transmit-Master Mode Register........................................................................................................................223  
11.5.2 Interrupt Information Registers..........................................................................................................................223  
11.5.3 T1 Transmit Control Registers ..........................................................................................................................224  
11.5.4 T1 Transmit Status and Information..................................................................................................................229  
11.5.5 T1 Per-Channel Loopback ................................................................................................................................232  
11.5.6 T1 Transmit DS0 Monitoring Function...............................................................................................................233  
11.5.7 T1 Transmit Signaling Operation.......................................................................................................................233  
11.5.8 T1 Transmit Per-Channel Idle Code Insertion...................................................................................................237  
11.5.9 T1 Transmit Channel Mark Registers................................................................................................................238  
11.5.10 Fractional T1 Support (Gapped Clock Mode)....................................................................................................239  
11.5.11 T1 Transmit Bit Oriented Code (BOC) Controller..............................................................................................240  
11.5.12 T1 Transmit FDL...............................................................................................................................................241  
11.5.13 Transmit SLC–96 Operation .............................................................................................................................241  
11.5.14 Transmit HDLC Controller.................................................................................................................................242  
Transmit Interrupt Mask Register 2 .................................................................................................................................247  
11.5.15 Programmable In-Band Loop-Code Generator .................................................................................................248  
11.5.16 Interfacing the T1 Tx Formatter to the BERT ....................................................................................................250  
11.5.17 T1 Transmit Synchronizer .................................................................................................................................252  
11.6 E1 RECEIVE FRAMER .................................................................................................................................254  
11.6.1 E1 Receive Framer Description and Operation.................................................................................................257  
11.6.2 Receive Master Mode Register.........................................................................................................................257  
11.6.3 Interrupt Information Registers..........................................................................................................................259  
11.6.4 E1 Receive Control Registers...........................................................................................................................259  
11.6.5 E1 Receive Status and Information...................................................................................................................263  
11.6.6 E1 Error Count Registers..................................................................................................................................275  
11.6.7 DS0 Monitoring Function...................................................................................................................................278  
11.6.8 E1 Receive Signaling Operation .......................................................................................................................279  
11.6.9 E1 Receive Per-Channel Idle Code Insertion....................................................................................................281  
11.6.10 E1 Receive Channel Mark Registers ................................................................................................................282  
11.6.11 Fractional E1 Support (Gapped Clock Mode) ...................................................................................................282  
11.6.12 Additional Sa-Bit and Si-Bit Receive Operation (E1 Mode)...............................................................................284  
11.6.13 Receive Framer HDLC Controller .....................................................................................................................290  
11.6.14 Interfacing the E1 Rx Framer to the BERT........................................................................................................297  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7 E1 TRANSMIT FRAMER................................................................................................................................299  
11.7.1 Transmit Master Mode Register........................................................................................................................302  
11.7.2 Interrupt Information Registers..........................................................................................................................303  
11.7.3 E1 Transmit Control Registers..........................................................................................................................303  
11.7.4 E1 Transmit Status and Information..................................................................................................................306  
11.7.5 Per-Channel Loopback .....................................................................................................................................308  
11.7.6 E1 Transmit DS0 Monitoring Function ..............................................................................................................309  
11.7.7 E1 Transmit Signaling Operation ......................................................................................................................310  
11.7.8 E1 Transmit Per-Channel Idle Code Insertion...................................................................................................314  
11.7.9 E1 Transmit Channel Mark Registers ...............................................................................................................315  
11.7.10 Fractional E1 Support (Gapped Clock Mode) ...................................................................................................315  
11.7.11 Additional (Sa) and International (Si) Bit Operation (E1 Mode).........................................................................316  
11.7.12 E1 Transmit HDLC Controller ...........................................................................................................................323  
11.7.13 Interfacing the E1 Transmitter to the BERT ......................................................................................................329  
11.7.14 E1 Transmit Synchronizer.................................................................................................................................331  
12 LINE INTERFACE UNIT (LIU)  
12.1 LIU REGISTERS..........................................................................................................................................334  
13 BIT ERROR RATE TESTER (BERT) 341  
13.1 BERT REGISTER BIT DESCRIPTIONS...........................................................................................................342  
14 JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT 348  
333  
14.1 TAP CONTROLLER STATE MACHINE............................................................................................................349  
14.2 INSTRUCTION REGISTER .............................................................................................................................351  
14.3 TEST REGISTERS........................................................................................................................................352  
15 PIN ASSIGNMENT  
353  
354  
355  
356  
357  
16 PACKAGE MECHANICAL INFORMATION  
17 PACKAGE THERMAL INFORMATION  
18 ABSOLUTE MAXIMUM RATINGS  
19 AC TIMING  
19.1 TRANSMIT TDM PORT AC CHARACTERISTICS .............................................................................................359  
19.2 RECEIVE TDM PORT AC CHARACTERISTICS ...............................................................................................360  
19.3 HIGH SPEED PORT AC CHARACTERISTICS...................................................................................................361  
19.4 SYSTEM INTERFACE AC CHARACTERISTICS.................................................................................................362  
19.5 MICROPROCESSOR BUS AC CHARACTERISTICS...........................................................................................364  
19.6 JTAG INTERFACE TIMING ...........................................................................................................................367  
20 REVISION CHANGE HISTORY  
368  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
LIST OF FIGURES  
Figure 1-1 Block Diagram............................................................................................................................................ 9  
Figure 2-1 Backplane Interface Diagram For Port 1 of 4........................................................................................... 14  
Figure 3-1 ATM Over 4 Ports..................................................................................................................................... 15  
Figure 3-2 IP Over 4 T1/E1 Ports.............................................................................................................................. 15  
Figure 3-3 IP Over 2 Ports, TDM Over 2 Ports.......................................................................................................... 15  
Figure 3-4 ATM Over 2 Ports, 2 Ports Combined Into High Speed TDM.................................................................. 15  
Figure 3-5 Fractional ATM Over 4 Ports With Fractional TDM Access to Each Port................................................ 16  
Figure 3-6 8 Port High Speed TDM Bus.................................................................................................................... 16  
Figure 7-1 Receive TDM Signals............................................................................................................................... 32  
Figure 7-2 Receive TDM Signals, Details.................................................................................................................. 32  
Figure 7-3 Transmit TDM Signals.............................................................................................................................. 33  
Figure 7-4 Transmit TDM Signals, Details................................................................................................................. 33  
Figure 7-5 Two Port High Speed TDM Bus............................................................................................................... 34  
Figure 7-6 Four Port High Speed TDM Bus .............................................................................................................. 35  
Figure 7-7 UTOPIA Level 2 Transmit Cell Transfer Direct Mode.............................................................................. 36  
Figure 7-8 UTOPIA Level 2 Receive Cell Transfer Direct Mode............................................................................... 36  
Figure 7-9 UTOPIA Level 2 Transmit Multiple Cell Transfer Polled Mode................................................................ 37  
Figure 7-10 UTOPIA Level 2 Receive Multiple Cell Transfer Polled Mode............................................................... 38  
Figure 7-11 UTOPIA Level 2 Receive Unexpected Multiple Cell Transfer ............................................................... 38  
Figure 7-12 UTOPIA Level 3 Transmit Multiple Cell Transfer Direct Mode .............................................................. 39  
Figure 7-13 UTOPIA Level 3 Transmit Multiple Cell Transfer Polled Mode.............................................................. 41  
Figure 7-14 UTOPIA Level 3 Receive Multiple Cell Transfer Direct Mode ............................................................... 42  
Figure 7-15 UTOPIA Level 3 Receive Multiple Cell Transfer Polled Mode............................................................... 42  
Figure 7-16 Transmit Multiple Packet Transfer to Different PHY ports (direct status mode).................................... 43  
Figure 7-17 POS-PHY Level 2 Receive Multiple Packet Transfer from Different PHY Ports/Devices (direct status  
mode) ................................................................................................................................................................ 44  
Figure 7-18 POS-PHY Level 2 Transmit Multiple Packet Transfer to Different PHY Ports (polled status mode)..... 45  
Figure 7-19 POS-PHY Level 2 Receive Multiple Packet Transfer (polled status mode) .......................................... 46  
Figure 7-20 POS-PHY Level 3 Transmit Multiple Packet Transfer In-Band Addressing .......................................... 47  
Figure 7-21 POS-PHY Level 3 Receive Multiple Packet Transfer In-Band Addressing ........................................... 48  
Figure 8-1 Normal Packet Format in 16-Bit Mode..................................................................................................... 50  
Figure 8-2 Byte Reordered Packet Format in 16-Bit Mode....................................................................................... 51  
Figure 8-3 Receive DSS Scrambler Synchronization State Diagram ....................................................................... 58  
Figure 8-4 Cell Delineation State Diagram................................................................................................................ 59  
Figure 8-5 HEC Error Monitoring State Diagram....................................................................................................... 60  
Figure 8-6 Cell Format for 53-Byte Cell With 16-Bit Data Bus .................................................................................. 60  
Figure 8-7 Cell Format for 52-Byte Cell With 16-Bit Data Bus .................................................................................. 61  
Figure 8-8 Remote Loopback.................................................................................................................................... 65  
Figure 8-9 Payload Loopback.................................................................................................................................... 65  
Figure 8-10 Framer Loopback................................................................................................................................... 66  
Figure 8-11 HSSYNC Input in H.100 (CT Bus) Mode ............................................................................................... 67  
Figure 8-12 Receive HDLC Example ........................................................................................................................ 73  
Figure 8-13 HDLC Message Transmit Example........................................................................................................ 77  
Figure 8-14 HSSYNC Input in H.100 (CT Bus) Mode ............................................................................................... 79  
Figure 8-15 Receive HDLC Example ........................................................................................................................ 82  
Figure 8-16 CRC Update Flow Diagram ................................................................................................................... 84  
Figure 8-17 Time Slot Numbering Schemes ............................................................................................................. 85  
Figure 8-18 E1 HDLC Message Transmit Example .................................................................................................. 87  
Figure 9-1 T1/J1 Transmit Pulse Templates ............................................................................................................. 90  
Figure 9-2 E1 Transmit Pulse Templates.................................................................................................................. 91  
Figure 9-3 Typical Monitor Operation........................................................................................................................ 92  
Figure 9-4 Jitter Tolerance ........................................................................................................................................ 95  
Figure 9-5 Jitter Attenuation ...................................................................................................................................... 96  
Figure 11-1 Transmit FIFO Register Map................................................................................................................ 118  
Figure 11-2 E1 Sync/Resync Criteria ...................................................................................................................... 260  
Figure 14-1 JTAG Functional Block Diagram.......................................................................................................... 348  
Figure 14-2 TAP Controller State Diagram.............................................................................................................. 349  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 15-1 DS26556 Pin Assignments—256-Lead BGA....................................................................................... 353  
Figure 19-1 Clock Period and Duty Cycle Definitions ............................................................................................. 357  
Figure 19-2 Rise Time, Fall Time, and Jitter Definitions ......................................................................................... 357  
Figure 19-3 Hold, Setup, and Delay Definitions (Rising Clock Edge) ..................................................................... 357  
Figure 19-4 Hold, Setup, and Delay Definitions (Falling Clock Edge)..................................................................... 358  
Figure 19-5 To/From High-Z Delay Definitions (Rising Clock Edge)....................................................................... 358  
Figure 19-6 To/From High-Z Delay Definitions (Falling Clock Edge)...................................................................... 358  
Figure 19-7 Intel Bus Read Timing (BTS = 0) ......................................................................................................... 365  
Figure 19-8 Intel Bus Write Timing (BTS = 0) ......................................................................................................... 365  
Figure 19-9 Motorola Bus Read Timing (BTS = 1).................................................................................................. 366  
Figure 19-10 Motorola Bus Write Timing (BTS = 1)................................................................................................ 366  
Figure 19-11 JTAG Interface Timing Diagram ........................................................................................................ 367  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
LIST OF TABLES  
Table 3-1 Framer LIU Compliance ............................................................................................................................ 17  
Table 3-2 Cell/Packet Interface Compliance............................................................................................................. 18  
Table 5-1 Short Pin List ............................................................................................................................................. 20  
Table 5-2 Pin Descriptions ........................................................................................................................................ 23  
Table 8-1 T1 Alarm Criteria ....................................................................................................................................... 68  
Table 8-2 E1 Line Code Violation Counting Options................................................................................................. 80  
Table 9-1 Loss Criteria T1.231, G.775 and ETSI 300 233 Specifications ................................................................ 94  
Table 10-1 Overall Register Map............................................................................................................................... 98  
Table 10-2 Per Port Register Map............................................................................................................................. 99  
Table 11-1 Global Register Map.............................................................................................................................. 100  
Table 11-2 General Cell / Packet Register Map...................................................................................................... 114  
Table 11-3 Transmit Cell Processor Register Map ................................................................................................. 123  
Table 11-4 Transmit Packet Processor Register Map ............................................................................................ 130  
Table 11-5 Receive Cell Processor Register Map .................................................................................................. 136  
Table 11-6 Receive Packet Processor Register Map ............................................................................................. 151  
Table 11-7 Receive FIFO Register Map.................................................................................................................. 163  
Table 11-8 Transmit System Interface Register Map.............................................................................................. 166  
Table 11-9 Receive System Interface Register Map............................................................................................... 168  
Table 11-10 T1 Receive Framer Register Map....................................................................................................... 171  
Table 11-11 T1 Line-Code Violation Counting Options........................................................................................... 193  
Table 11-12 T1 Path-Code Violation Counting Arrangements................................................................................ 194  
Table 11-13 T1 Frame Out-of-Sync Counting Arrangements ................................................................................. 195  
Table 11-14 T1 Transmit Framer Register Map...................................................................................................... 220  
Table 11-15 E1 Receive Framer Register Map....................................................................................................... 254  
Table 11-16 E1 Alarm Criteria................................................................................................................................. 264  
Table 11-17 E1 Line Code Violation Counting Options........................................................................................... 276  
Table 11-18 E1 Transmit Framer Register Map...................................................................................................... 299  
Table 11-19 E1 Transmit Signaling - CAS Format.................................................................................................. 310  
Table 11-20 E1 Transmit Signaling – CCS Format................................................................................................. 310  
Table 12-1 LIU Register Map .................................................................................................................................. 333  
Table 12-2 Internal Transmit Termination Select .................................................................................................... 335  
Table 12-3 E1 Transmit Pulse Shape Selection...................................................................................................... 336  
Table 12-4 T1/J1 Transmit Pulse Shape Selection................................................................................................. 336  
Table 12-5 Receive Level Indication ....................................................................................................................... 339  
Table 12-6 Internal Receive Termination Selection ................................................................................................ 340  
Table 12-7 Monitor Gain and Maximum Receive Sensitivity Selection................................................................... 340  
Table 13-1 BERT Register Map .............................................................................................................................. 341  
Table 14-1 Instruction Codes for IEEE 1149.1 Architecture ................................................................................... 351  
Table 14-2 ID Code Structure.................................................................................................................................. 352  
Table 17-1 Thermal Characteristics ........................................................................................................................ 355  
Table 18-1 Absolute Maximum Ratings................................................................................................................... 356  
Table 18-2 Recommended DC Operating Conditions............................................................................................. 356  
Table 18-3 Capacitance........................................................................................................................................... 356  
Table 18-4 DC Operating Characteristics ............................................................................................................... 356  
Table 19-1 Transmit TDM Port Timing .................................................................................................................... 359  
Table 19-2 Receive TDM Port Timing ..................................................................................................................... 360  
Table 19-3 Receive TDM Port Timing ..................................................................................................................... 361  
Table 19-4 System Interface Level 2 Timing........................................................................................................... 362  
Table 19-5 System Interface Level 3 Timing........................................................................................................... 363  
Table 19-6 AC Characteristics—Microprocessor Bus Timing................................................................................. 364  
Table 19-7 JTAG Interface Timing .......................................................................................................................... 367  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
1 BLOCK DIAGRAMS  
Figure 1-1 Block Diagram  
Per Port  
TDM  
Interface  
High  
Speed Bus  
Interface  
DS26556  
TSCLK  
TADR[4:0]  
TDATA[15:0]  
TPRTY  
Tx Cell  
DS1/ E1  
TRANSMIT  
FORMATTER  
Processor  
TEN  
TDXA[4:2]  
TDXA[1]/TPXA  
TSOX  
TSPA  
TEOP  
TSX  
TMOD  
TERR  
Tx  
FIFO  
Transmit  
DS1/E1  
LIU  
TTIPn  
Tx Packet  
Processor  
TRINGn  
TX BERT  
RX BERT  
HDLC  
RSCLK  
Rx Packet  
Processor  
RADR[4:0]  
RDATA[15:0]  
RPRTY  
Rx  
DS1/E1  
Receive  
LIU  
DS1/E1  
RECEIVE  
FRAMER  
RTIPn  
RRINGn  
FIFO  
REN  
Rx Cell  
Processor  
RDXA[1]/RPXA  
/RSX  
RDXA[4:2]  
RSOX  
Per Port  
TDM  
Interface  
High  
Speed Bus  
Interface  
REOP  
IEEE P1149.1  
JTAG Test  
Access Port  
RVAL  
MICROPROCESSOR  
INTERFACE  
Clock Rate  
Adapter  
RMOD  
RERR  
n = port #  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
2 FEATURES  
2.1 Framer/LIU  
2.1.1 Framer/Formatter  
Fully Independent Transmit and Receive Functionality  
Full Receive and Transmit Path Transparency  
T1 Framing Formats D4 and ESF per T1.403, and Expanded SLC-96 Support (TR-TSY-008)  
E1 FAS Framing and CRC-4 Multiframe per G.704/G.706 and G.732 CAS Multiframe  
Detailed Alarm and Status Reporting with Optional Interrupt Support  
Large Path and Line Error Counters for  
T1: BPV, CV, CRC6, and Framing Bit Errors  
E1: BPV, CV, CRC4, E-Bit, and Frame Alignment Errors  
Timed or Manual Update Modes  
DS1 Idle Code Generation on a Per-Channel Basis in Both Transmit and Receive Paths  
User-Defined  
Digital Milliwatt  
ANSI T1.403-1998 Support  
G.965 V5.2 Link Detect  
Ability to Monitor One DS0 Channel in Both the Transmit and Receive Paths  
In-Band Repeating Pattern Generators and Detectors  
Three Independent Detectors  
Patterns from 1 to 8 bits or 16 bits in Length  
Bit Oriented Code (BOC) Support  
Signaling Support  
Software based  
Interrupt Generated on Change of Signaling Data  
Hardware Pins Provided to Indicate Loss of Frame, Loss of Signal and Loss-of-Transmit Clock (LOTC)  
Automatic RAI Generation to ETS 300 011 Specifications  
RAI-CI and AIS-CI Support  
Expanded Access to Sa and Si Bits  
Option to Extend Carrier Loss Criteria to a 1ms Period as per ETS 300 233  
Japanese J1 Support  
Ability to Calculate and Check CRC6 According to the Japanese Standard  
Ability to Generate Yellow Alarm According to the Japanese Standard  
2.1.2 Line Interface (LIU)  
Requires only a 2.048MHz master clock for both E1 and T1 operation with the option to use 1.544MHz for T1  
operation  
Fully software configurable  
Short-haul and long-haul applications  
Automatic receive sensitivity adjustments  
Ranges include 0 to 43dB or 0 to 12dB for E1 applications and 0 to 13dB or 0 to 36dB for T1 applications  
Receive level indication in 2.5dB steps from  
-42.5dB to -2.5dB  
Internal receive termination option for 75, 100, and 120Ω lines  
Internal transmit termination option for 75, 100, and 120Ω lines  
Monitor application gain settings of 20dB, 26dB, and 32dB  
G.703 receive synchronization-signal mode  
Flexible transmit waveform generation  
T1 DSX-1 line build-outs  
T1 CSU line build-outs of -7.5dB, -15dB, and -22.5dB  
E1 waveforms include G.703 waveshapes for both 75Ω coax and 120Ω twisted cables  
AIS generation independent of loopbacks  
Alternating ones and zeros generation  
Square-wave output  
Open-drain output option  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
NRZ format option  
Transmitter power-down  
Transmitter 50mA short-circuit limiter with current-limit-exceeded indication  
Transmit open-circuit-detected indication  
2.1.3 Clock Synthesizer  
Output frequencies include 2.048MHz, 4.096MHz, 8.192MHz, and 16.384MHz  
Derived from recovered receive clock  
2.1.4 HDLC Controllers  
HDLC Engine (One per Framer):  
Independent 64-byte Rx and Tx Buffers with Interrupt Support  
Access FDL, Sa, or Single DS0 Channel  
Compatible with Polled or Interrupt Driven Environments  
2.1.5 Test and Diagnostics  
Full-Featured BERTs  
Programmable PRBS pattern – The Pseudo Random Bit Sequence (PRBS) polynomial (xn + xy + 1) and  
seed are programmable (length n = 1 to 32, tap y = 1 to n - 1, and seed = 0 to 2n - 1).  
Programmable repetitive pattern – The repetitive pattern length and pattern are programmable (the length  
n = 1 – 32 and pattern = 0 – 2n - 1).  
24-bit error count and 32-bit bit count registers  
Programmable bit error insertion – Errors can be inserted individually, on a pin transition, or at a specific  
rate. The rate 1/10n is programmable (n = 1 to 7).  
Pattern synchronization at a 10-3 BER – Pattern synchronization will be achieved even in the presence of a  
random Bit Error Rate (BER) of 10-3.  
BPV Insertion  
F-Bit Corruption for Line Testing  
Loopbacks  
Remote  
Local  
Per-Channel  
IEEE 1149.1 Support  
2.2 Cell/Packet Interface  
2.2.1 General  
Programmable system interface type – When performing cell mapping/demapping, the system interface can  
be programmed as a UTOPIA Level 2 Bus or a UTOPIA Level 3 Bus or a POS-PHY Level 2 or Level 3 Bus.  
When performing packet mapping/demapping, the system interface can be programmed as a POS-PHY Level  
2 Bus or a POS-PHY Level 3 Bus.  
Selectable system interface bus width – The data bus can be a 16-bit or 8-bit bus.  
Supports clock speeds up to 52 MHz.  
Supports multiple ports on the system interface – Each line has its own port address for access via the  
system interface.  
Programmable system interface port address – The address assigned to each system interface port is  
programmable to allow multiple devices to operate on the same bus.  
Supports per port system loopback – Each port has can be placed in system loopback which causes  
cells/packets from the transmit FIFO to looped back to the receive FIFO.  
System interface bit/byte reordering – In 16-bit mode the order of the bytes as transferred across the system  
interface is programmable, i.e., the first byte received/transmitted can be transferred in ([15:8]) or [7:0]. The  
order of the bits as transferred across the system interface is programmable on a per port basis, i.e., the first  
bit received/transmitted can be transferred in bit position 7 (15 and 7) or bit position 0 (8 and 0).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
2.2.2 ATM  
Programmable HEC insertion and extraction – The transmit side can be programmed to accept cells from  
the system interface that do or do not contain a HEC byte. If cells are transferred without a HEC byte, the HEC  
byte will be computed and inserted. If cells are transferred with a HEC byte, then the transferred HEC byte can  
be programmed to be passed through or overwritten with a newly calculated HEC. The receive side can be  
programmed to send cells to the system interface that do or don't contain the HEC byte.  
Programmable errored cell insertion – An HEC error mask can be programmed for insertion of a single or  
multiple errors individually or continuously at a programmable rate.  
Programmable transmit cell synchronization – The transmit data line can be provisioned to be bit  
synchronous, byte synchronous, or cell synchronous.  
HEC based cell delineation – Cell delineation is determined from the HEC.  
Programmable header cell pass-through – Receive cell filtering can pass-through only those cells that  
matching a programmable header value.  
Selectable idle/unassigned/invalid/programmable header cell padding and filtering – Transmit cell  
padding can be programmed for idle cell or programmable header cell padding. The padded cell payload byte  
contents are also programmable. Receive cell filtering can be programmed for any combination of idle cell,  
unassigned cell, invalid cell, or programmable header cell filtering. Or, all cell filtering can be disabled.  
Optional header error correction – Receive side single bit header error correction can enabled.  
Separate corrected and uncorrected errored cell counts – Separate counts of errored cells containing a  
corrected HEC error, and cells containing non-corrected HEC errors are kept.  
Optional HEC uncorrected errored cell filtering – Uncorrected errored cell extraction can be disabled.  
Selectable cell scrambling/descrambling – Cell scrambling and/or descrambling can be disabled. The  
scrambling can be a self-synchronous scrambler (x43 + 1) over the payload only, a self-synchronous scrambler  
over the entire cell, or a Distributed Sample Scrambler (x31 + x28 + 1).  
Optional HEC calculation coset polynomial addition – The performance of coset polynomial addition during  
HEC calculation can be disabled.  
2.2.3 HDLC  
Programmable FCS insertion and extraction – The transmit side can be programmed to accept packets  
from the system interface that do or don't contain FCS bytes. If packets are transferred without FCS bytes, the  
FCS will be computed and appended to the packet. If packets are transferred with FCS bytes, then the FCS  
can be programmed to be passed through or overwritten with a newly calculated FCS. The receive side can be  
programmed to send packets to the system interface that do or don't contain FCS bytes.  
Programmable transmit packet synchronization – The transmit data line can be provisioned to be bit  
synchronous or byte synchronous.  
Programmable FCS type – The FCS can be programmed to be a 16-bit FCS or a 32-bit FCS.  
Supports FCS error insertion – FCS error insertion can be programmed for insertion of errors individually or  
continuously at a programmable rate.  
Supports bit or byte stuffing/destuffing – The bit or byte synchronous mode determines the bit or byte  
stuffing/destuffing.  
Programmable packet size limits – The receive side can be programmed to abort packets over a  
programmable maximum size or under a programmable minimum size. The maximum packet size allowed is  
65,535 bytes.  
Selectable packet scrambling/descrambling – Packet scrambling and/or descrambling can be disabled.  
Separate FCS errored packet and aborted packet counts – Separate counts of aborted packets, size  
violation packets, and FCS errored packets are kept.  
Optional errored packet filtering – Errored packet extraction can be disabled  
Programmable inter-frame fill – The transmit inter-frame fill value is programmable.  
2.3 Control Port  
8-Bit Parallel Control Port  
Intel or Motorola Nonmultiplexed Support  
Flexible Status Registers Support Polled, Interrupt, or Hybrid Program Environments  
Software Reset Supported  
Hardware Reset Pin  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
13 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 2-1 Backplane Interface Diagram For Port 1 of 4  
MULTIFRAME SYNC  
RSYNC  
FRAME SYNC  
PORT 1  
RECEIVE  
TDM  
CHANNEL MARKER  
RCHMRK  
RCLK  
RECOVERED CLOCK  
RECOVERED DATA  
BUS  
RSER  
CHANNEL  
MARKER  
CLOCK  
CLOCK  
SYNC  
DATA  
RECEIVE  
CELL / PACKET  
BUS  
(COMMON TO ALL  
PORTS)  
DATA  
RECEIVE  
FRAMER  
SYNCIN  
SYNCOUT  
PORTS  
2 - 4  
RECEIVE  
CELL / PACKET  
CONTROLLER  
ELASTIC  
STORE  
SIG  
BUFFER  
CLOCK OUT  
SYNC OUT  
SYNC IN  
HSYSCLK  
HSSYNC  
HRDATA  
HRSIG  
HIGH SPEED  
MULTIPLEXED  
BUS  
RDATA  
RSIG  
TDATA  
TSIG  
HTDATA  
HTSIG  
PORTS  
2 - 4  
HIGH SPEED  
MULTIPLEXED  
CONTROLLER  
CHANNEL MARKER  
TCHMRK  
TCLK  
TRANSMIT CLOCK  
TRANSMIT SYNC  
PORT 1  
TRANSMIT  
TDM  
TO  
TX  
LIU  
TSYNC (I/O)  
TSERI  
BUS  
TRANSMIT DATA  
TSERO  
CLOCK  
DATA  
DATA OUT  
SYNC IN  
CLOCK  
TRANSMIT SYNC OUT  
SYNCIN  
TRANSMIT  
CELL / PACKET  
BUS  
(COMMON TO ALL  
PORTS)  
TX  
TRANSMIT  
FRAMER  
ELASTIC  
STORE  
CHANNEL  
MARKER  
PORTS  
2 - 4  
SIG  
BUFFER  
TRANMSIT  
CELL / PACKET  
CONTROLLER  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
3 BACKPLANE CONFIGURATION SCENERIOS  
Figure 3-1 ATM Over 4 Ports  
XCEIVER  
T1/E1 #1  
XCEIVER  
T1/E1 #2  
T1/E1 #3  
T1/E1 #4  
UTOPIA  
I/F  
ATM  
XCEIVER  
XCEIVER  
Figure 3-2 IP Over 4 T1/E1 Ports  
XCEIVER  
T1/E1 #1  
XCEIVER  
T1/E1 #2  
T1/E1 #3  
T1/E1 #4  
PACKET  
I/F  
IP  
XCEIVER  
XCEIVER  
Figure 3-3 IP Over 2 Ports, TDM Over 2 Ports  
XCEIVER  
T1/E1 #1  
T1/E1 #2  
T1/E1 #3  
T1/E1 #4  
PACKET  
I/F  
IP  
XCEIVER  
XCEIVER  
XCEIVER  
TDM  
TDM  
Figure 3-4 ATM Over 2 Ports, 2 Ports Combined Into High Speed TDM  
XCEIVER  
T1/E1 #1  
T1/E1 #2  
T1/E1 #3  
T1/E1 #4  
UTOPIA  
I/F  
ATM  
XCEIVER  
XCEIVER  
XCEIVER  
ELASTIC  
BUFFERS  
2X HIGH SPEED  
TDM  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 3-5 Fractional ATM Over 4 Ports With Fractional TDM Access to Each Port  
T1/E1 #1  
T1/E1 #2  
T1/E1 #3  
T1/E1 #4  
XCEIVER  
XCEIVER  
XCEIVER  
XCEIVER  
UTOPIA  
I/F  
ATM  
FRACTIONAL TDM  
ACCESS TO PORT 1  
FRACTIONAL TDM  
ACCESS TO PORT 2  
FRACTIONAL TDM  
ACCESS TO PORT3  
FRACTIONAL TDM  
ACCESS TO PORT4  
Figure 3-6 8 Port High Speed TDM Bus  
DS26556 #1  
T1/E1 PORT 1  
T1/E1 PORT 2  
T1/E1 PORT 3  
T1/E1 PORT 4  
16.384 MHz System Clock In  
System 8KHz Frame Sync In  
TDM Receive Signaling Out  
TDM Transmit Signaling In  
TDM Receive Data Out  
HSYSCLK  
HSSYNC  
HRSIG  
HTSIG  
HRDATA  
HTDATA  
TDM Transmit Data In  
DS26556 #2  
T1/E1 PORT 5  
T1/E1 PORT 6  
T1/E1 PORT 7  
T1/E1 PORT 8  
HSYSCLK  
HSSYNC  
HRSIG  
HTSIG  
HRDATA  
HTDATA  
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Standards Compliance  
The DS26556 conforms to the applicable parts of the following standards.  
Table 3-1 Framer LIU Compliance  
SPECIFICATION  
TITLE  
ANSI  
T1.102-1993  
T1.107-1995  
T1.231-1997  
T1.403-1999  
AT&T  
Digital Hierarchy—Electrical Interfaces  
Digital Hierarchy—Formats Specification  
Digital Hierarchy—Layer 1 In-Service Digital Transmission Performance Monitoring  
Network and Customer Installation Interfaces—DS1 Electrical Interface  
Requirements for Interfacing Digital Terminal Equipment to Services Employing the  
Extended Superframe Format  
TR54016  
TR62411  
High Capacity Digital Service Channel Interface Specification  
ITU  
Synchronous Frame Structures used at 1544, 6312, 2048, 8488, and 44,736 kbit/s  
Hierarchical Levels  
Frame Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to Basic  
Frame Structures Defined in Recommendation G.704  
G.704, 1995  
G.706, 1991  
G.732, 1993  
G.736, 1993  
Characteristics of Primary PCM Multiplex Equipment Operating at 2048 kbit/s  
Characteristics of a synchronous digital multiplex equipment operating at 2048 kbit/s  
Loss Of Signal (LOS) and Alarm Indication Signal (AIS) Defect Detection and Clearance  
Criteria  
The Control of Jitter and Wander Within Digital Networks Which are Based on the  
2048kbps Hierarchy  
G.775, 1994  
G.823, 1993  
I.431, 1993  
O.151, 1992  
O.161, 1988  
ETSI  
Primary Rate User-Network Interface—Layer 1 Specification  
Error Performance Measuring Equipment Operating at the Primary Rate and Above  
In-service code violation monitors for digital systems  
Integrated Services Digital Network (ISDN); Primary rate User-Network Interface (UNI);  
Part 1: Layer 1 specification  
ETS 300 011, 1998  
Transmission and multiplexing; Physical/electrical characteristics of hierarchical digital  
ETS 300 166, 1993 interfaces for equipment using the 2048 kbit/s-based plesiochronous or synchronous digital  
hierarchies  
ETS 300 233, 1994 Integrated Services Digital Network (ISDN); Access digital section for ISDN primary rate  
Integrated Services Digital Network (ISDN); Attachment requirements for terminal  
equipment to connect to an ISDN using ISDN primary rate access  
CTR 4, 1995  
I.432, 1993  
B-ISDN User-Network Interface—Physical Layer Specification–ITU-T  
Business Telecommunications (BT); Open Network Provision (ONP) technical  
requirements; 2048 kbit/s digital unstructured leased lines (D2048U) attachment  
requirements for terminal equipment interface  
CTR 12, 1993  
Business Telecommunications (BTC); 2048 kbit/s digital structured leased lines (D2048S);  
Attachment requirements for terminal equipment interface  
CTR 13, 1996  
TTC  
JT-G.704, 1995  
JTI.431, 1995  
Frame Structures on Primary and Secondary Hierarchical Digital Interfaces  
ISDN Primary Rate User-Network Interface Layer 1 Specification  
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Table 3-2 Cell/Packet Interface Compliance  
Organization  
Number  
Title  
IETF  
RFC 1662  
RFC 2615  
OIF-SPI3-01.0  
PPP in HDLC-like Framing  
PPP over SONET  
System Packet Interface Level 3 (SPI-3): OC-48 System Interface for  
Physical and Link Layer Devices  
OIF  
ATM Forum  
af-uni-0010.002  
af-phy-0039.000  
af-bici-0013.003  
ATM User-Network Interface Specification, Version 3.1  
UTOPIA Level 2 Physical Layer Interface Specification  
BISDN Inter Carrier Interface (B-ICI) Specification Version 2.0  
(Integrated)  
af-phy-0136.000  
af-phy-0143.000  
I.361  
UTOPIA Level 3 Physical Layer Interface Specification  
Frame-based ATM Interface (Level 3)  
B-ISDN ATM Layer Specification  
ITU-T  
I.432.1  
B-ISDN User-Network Interface – Physical Layer Specification –  
General Characteristics  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
4 ACRONYMS AND GLOSSARY  
Definition of the terms used in this data sheet:  
Acronyms  
ATM – Asynchronous Transfer Mode  
CC52 – Clear Channel 52 Mbps (STS-1 Clock Rate)  
CLAD – Clock Rate Adapter  
CLR – Clear Channel Mode  
DSS – Distributed Sample Scrambler  
FFRAC – Flexible Fractional Mode  
FRM – Frame Mode  
HDLC – High Level Data Link Control  
SPI-3 – same as POS-PHY L3  
TDM – Time Division Multiplexing  
Glossary  
Cell – ATM cell  
Clear Channel – A data stream with no framing included  
Fractional – Uses only a portion of available payload for data, also known as subrate  
Octet Aligned – Byte aligned  
Packet – HDLC packet  
Subrate – See Fractional  
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5 PIN DESCRIPTIONS  
5.1 Short Pin List  
Table 5-1 Short Pin List  
Pin #  
Name  
Type  
Function  
Network Interface Signals  
Port Port Port Port  
4
3
2
1
TTIP[4:1]  
O
O
O
O
I
Transmit Tip  
Transmit Ring  
Secondary Transmit Tip  
Secondary Transmit Ring  
Receive Tip  
T1  
J1  
H1  
A1  
TRING[4:1]  
STTIP{4:1]  
STRING[4:1]  
RTIP[4:1]  
RRING[4:1]  
TXENABLE  
T3  
T2  
R3  
P1  
P2  
J3  
J2  
K3  
L1  
L2  
H3  
H2  
G3  
F1  
F2  
A3  
A2  
B3  
C1  
C2  
I
I
Receive Ring  
Transmit High Impedance Enable  
Backplane TDM Signals  
Transmit Serial Data Out  
Transmit Serial Data In  
Transmit Clock  
Transmit Sync  
Transmit Channel Marker  
Receive Serial Data  
M5  
TSERO[4:1]  
TSERI[4:1]  
TCLK[4:1]  
TSYNC[4:1]  
TCHMRK[4:1]  
RSER[4:1]  
RCLKO[4:1]  
RSYNC[4:1]  
RM_RFSYNC[4:1]  
RCHMRK[4:1]  
O
I
I
I/O  
O
O
O
O
O
O
M6  
R4  
P4  
P5  
N5  
T5  
L7  
R5  
L4  
P6  
T6  
N3  
R6  
P3  
N7  
M7  
L8  
D6  
F3  
A6  
E3  
B6  
B5  
E6  
A5  
K4  
C6  
D5  
A4  
C5  
C3  
F6  
E5  
C4  
D3  
J4  
Receive Clock Out  
Receive Sync  
Receive Multiframe Sync / Frame Sync  
Receive Channel Marker  
Backplane High Speed TDM Signals  
High Speed Bus Transmit Data  
High Speed Bus Transmit Signaling Data  
High Speed Bus Receive Data  
High Speed Bus Receive Signaling Data  
High Speed Bus System Clock  
High Speed Bus System Sync  
Status Signals  
L5  
N6  
T4  
B4  
HTDATA  
HTSIG  
HRDATA  
HRSIG  
HSYSCLK  
HSSYNC  
I
I
O
O
I
T9  
P9  
R9  
L10  
M9  
N9  
I/O  
ROCD[4:1]  
RLCD[4:1]  
RLOF/LOTC[4:1]  
RLOS[4:1]  
O
O
O
O
Receive Out of Cell Delineation  
Receive Loss of Cell Delineation  
Receive Loss of Frame / Loss of Transmit Clock N4  
Receive Loss of Signal L3  
Microcontroller Interface  
Address Bus[12:0]  
R11  
L11  
N14  
N11  
L6  
P14  
M11  
T11  
F5  
P11  
G4  
H4  
M4  
F4  
ADDR[12]  
ADDR[11]  
ADDR[10]  
ADDR[9]  
ADDR[8]  
ADDR[7]  
ADDR[6]  
ADDR[5]  
ADDR[4]  
ADDR[3]  
ADDR[2]  
ADDR[1]  
ADDR[0]  
I
F7  
E7  
D7  
C7  
B7  
A7  
E8  
C8  
A8  
B8  
D8  
F8  
B9  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Pin #  
Name  
Type  
Function  
Port Port Port Port  
4
3
2
1
DATA[7]  
DATA[6]  
DATA[5]  
DATA[4]  
DATA[3]  
DATA[2]  
DATA[1]  
DATA[0]  
CS  
WR(R/W)  
RD(DS)  
BTS  
INT  
HIZ  
I/O  
Data Bus[7:0]  
E9  
F9  
B10  
A10  
C10  
D10  
E10  
F10  
B11  
A11  
C11  
D11  
B12  
M3  
I
I
I
I
O
I
Chip Select  
Write Input (Read/Write)  
Read Input (Data Strobe)  
Bus Type Select  
Interrupt  
High Z  
JTAG  
I
I
JTAG Reset  
JTAG Clock  
JTAG Mode Select  
JTAG Data Input  
JTAG Data Output  
P10  
R10  
T10  
N10  
M10  
JTRST  
JTCLK  
JTMS  
JTDI  
Ipu  
Ipu  
O
JTDO  
Clock Signals  
I
I
Reset  
R8  
C9  
A9  
D9  
RESET  
MCLK  
REFCLK  
BPCLK  
Master Clock Input  
Reference Clock  
Backplane Clock Output  
I/O  
O
UTOPIA L2/3 or POS-PHY L2/3 or SPI-3 System Interface  
TSCLK  
TADR[4]  
TADR[3]  
TADR[2]  
TADR[1]  
TADR[0]  
I
I
Transmit System Clock  
Transmit Address [4:0]  
D16  
A13.  
D12  
B13  
E11  
A12  
M12  
L14  
M14  
R13  
T13  
P13  
D13  
E12  
N13  
L12  
M13  
L13  
R16  
T16  
T14  
R15  
C12  
C13  
C15  
TDATA[15]  
TDATA[14]  
TDATA[13]  
TDATA[12]  
TDATA[11]  
TDATA[10]  
TDATA[9]  
TDATA[8]  
TDATA[7]  
TDATA[6]  
TDATA[5]  
TDATA[4]  
TDATA[3]  
TDATA[2]  
TDATA[1]  
TDATA[0]  
TPAR  
I
Transmit Data [15:0]  
I
I
Transmit Parity  
Transmit Enable  
Transmit Direct cell/packet Available [1] / Polled  
cell/packet Available (tri-state)  
TEN  
TDXA[1] / TPXA  
Oz  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Pin #  
Name  
Type  
Function  
Port Port Port Port  
4
3
2
1
TDXA[4]  
TDXA[3]  
TDXA[2]  
TSOX  
TSPA  
TEOP  
TSX  
TMOD  
TERR  
RSCLK  
O
Transmit Direct cell/packet Available [4:2]  
F11  
B16  
C14  
P12  
C16  
T12  
R12  
F14  
N12  
H14  
J12  
I
Transmit Start Of cell/packet  
Transmit Selected Packet Available  
Transmit End Of Packet  
Transmit Start of Transfer  
Transmit packet data Modulus  
Transmit packet Error  
Oz  
I
I
I
I
I
I
Receive System Clock  
Receive Address [4:0]  
RADR[4]  
RADR[3]  
RADR[2]  
RADR[1]  
RADR[0]  
RDATA[15]  
RDATA[14]  
RDATA[13]  
RDATA[12]  
RDATA[11]  
RDATA[10]  
RDATA[9]  
RDATA[8]  
RDATA[7]  
RDATA[6]  
RDATA[5]  
RDATA[4]  
RDATA[3]  
RDATA[2]  
RDATA[1]  
RDATA[0]  
RPAR  
K13  
P16  
P15  
N15  
H13  
H12  
M15  
N16  
G13  
K15  
L15  
L16  
M16  
J13  
Oz  
Receive Data [15:0] (tri-state)  
J14  
J16  
K16  
G16  
H16  
F16  
F15  
D14  
D15  
Oz  
I
Oz  
Receive Parity (active low tri-state)  
Receive Enable (active low)  
Receive Direct cell/packet Available [1] / Polled  
cell/packet Available / Start of Transfer (tri-  
state)  
REN  
RDXA[1] / RPXA /  
RSX  
RDXA[4]  
RDXA[3]  
RDXA[2]  
RSOX  
REOP  
RVAL  
O
Receive Direct cell/packet Available [4:2]  
A16  
A14  
B15  
F12  
G15  
E15  
F13  
E13  
Oz  
Oz  
Oz  
Oz  
Oz  
Receive Start Of cell/packet (tri-state)  
Receive End Of Packet  
Receive packet data Valid  
Receive packet data Modulus  
Receive packet Error  
TEST  
RMOD  
RERR  
GTEST1  
GTEST2  
I
I
Global Test  
D4  
E4  
TTEST3  
TTEST2  
TTEST1  
RTEST3  
RTEST2  
RTEST1  
Transmit Test  
Receive Test  
M8  
N8  
L9  
P7  
T7  
R7  
I
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Pin #  
Name  
Type  
Function  
Port Port Port Port  
4
3
2
1
SCAN_EN  
SCAN_MODE  
I
Scan Enable  
Scan Mode  
P8  
T8  
POWER  
VSS  
VDD  
PWR  
PWR  
Ground, 0 Volt potential  
E14, K8, K7, K5, K6, J5, J9,  
J6, K11, K12, K10, K9, J10,  
J8, J11  
G6, G7, H5, G5, H9, G12,  
H6, G11,G10, H10, G9, J7,  
G8, H11  
Digital 3.3V  
AVDDRn  
AVDDTn  
AVDDC  
AVSSRn  
AVSSTn  
AVSSC  
PWR  
PWR  
PWR  
PWR  
PWR  
PWR  
Analog 3.3V for receive LIU on port n  
Analog 3.3V for transmit LIU on port n  
Analog 3.3V for CLAD  
Analog Gnd for receive LIU  
Analog Gnd for transmit LIU  
Analog Gnd for CLAD  
D1, E1, M1, N1  
B1, G1, K1, R1  
H7  
D2, E2, M2, N2  
B2, G2, K2, R2  
H8  
No Connects  
NC  
NC  
No Connect  
Note: Do not connect any signal to these balls,  
leave unconnected.  
A15, B14, E16, G14, H15,  
J15, K14, R14, T15  
5.2 Detailed Pin List  
Table 5-2 Pin Descriptions  
Signal Name  
I/O Description  
Backplane TDM Signals  
RSER[4:1]  
O
Receive Serial Data  
This output is the recovered raw data stream containing all overhead T1, E1 or J1  
bits. This signal is updated on the rising edge of RCLK output.  
Receive Clock Out  
This output is the recovered network clock under normal conditions. During loss  
of signal conditions this clock is derived from the scaled signal at MCLK.  
Receive Sync  
An output sync pulse indicating the frame or multiframe boundaries in the data at  
RSER.  
Receive Multiframe or Frame Sync  
RCLKO[4:1]  
O
O
O
RSYNC[4:1]  
RM_RFSYNC [4:1]  
An output sync pulse indicating the frame or multiframe boundaries in the data at  
RSER in normal operation. When the high-speed bus is enabled, this output will  
indicate frame boundaries associated with the high-speed, multiplexed TDM bus  
operation.  
RCHMRK[4:1]  
O
Receive Channel Marker  
This output signal is user definable to be a cell/packet-mapping indicator in which  
it is high during channels mapped to the cell/packet interface or a channel clock.  
As a cell/packet mapping indicator this signal will be high during channels mapped  
to the cell/packet interface and can be used to de-multiplex non cell/packet data  
from the data stream at RSER. As a channel clock the user can program this  
output to pulse during the LSB of all channel times or produce a gated clock  
during any combinations of channels in both 64kbps or 56 kbps mode. RCHMRK  
is updated on the rising edge of RCLK.  
23 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
TSERO[4:1]  
TSERI[4:1]  
O
I
Transmit Serial Data Out  
This is the output of the transmit cell/packet interface. In a pure cell/packet  
operation this pin can be connected to TSERI. This signal along with TCHMRK  
and TSERI can be used to multiplex TDM data with the cell/packet data. TSERO  
is updated on the rising edge of TCLK  
Transmit Serial Data In  
This is the input to the transmit framer. In a pure cell/packet operation this pin can  
be connected to TSERO. This signal along with TCHMRK and TSERO can be  
used to multiplex TDM data with the cell/packet data. This signal is sampled on  
the falling edge of TCLK.  
TCLK[4:1]  
I
Transmit Clock  
A 1.544 MHz or a 2.048MHz primary transmit clock. Under normal operation this  
signal clocks data through the transceiver onto the network.  
TSYNC[4:1]  
I/O  
Transmit Sync  
This signal can be defined as an output or input in either a frame or multiframe  
format.  
As an output, it is updated on the rising edge of TCLK. If the transmit  
synchronizer is enabled, this output will be synchronous to the embedded framing  
overhead in the signal present at TSERI. If there is no embedded framing  
overhead in the TSERI signal (the transmit synchronizer is disabled), TSYNC will  
assume an arbitrary alignment and it is up to the user to align data at TSERI with  
TSYNC.  
As an input, the user can force the transmit framer to align to the data present at  
TSERI. If the data at TSERI contains complete framing overhead the user can  
program the transmit framer to pass the overhead bits unmolested. Otherwise the  
transmit framer will calculate and insert all the appropriate overhead depending on  
the operational mode selected. TSYNC is sampled on the falling edge of TCLK.  
TCHMRK[4:1]  
O
Transmit Channel Marker  
This output signal is user definable to be a cell/packet-mapping indicator in which  
it is high during channels mapped to the cell/packet interface or a channel clock.  
As a cell/packet mapping indicator this signal will be high during channels mapped  
to the cell/packet interface and can be used to multiplex non cell/packet data with  
the data stream at TSERO. As a channel clock the user can program this output  
to pulse during the LSB of all channel times or produce a gated clock during any  
combinations of channels in both 64kbps or 56 kbps mode. TCHMRK is updated  
on the rising edge of TCLK.  
Backplane HS TDM Signals  
HRDATA  
HTDATA  
HSYSCLK  
HTSIG  
O
High Speed Bus Receive Data  
This output is the frame interleaved received data bus. This signal is updated on  
the rising edge of HSYSCLK.  
High Speed Bus Transmit Data  
This input is the frame interleaved transmit data bus. This signal is sampled on  
the falling edge of HSYSCLK.  
High Speed Bus System Clock  
A 2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz clock used to drive the high  
speed multiplexed bus.  
High Speed Bus Transmit Signaling TDM Stream  
Input for the TDM signaling data to be inserted into the transmit data stream. This  
signal is sampled on the falling edge of HSYSCLK.  
High Speed Bus Receive Signaling TDM Stream  
This output is the extracted TDM signaling data from the receive data stream.  
This signal is updated on the rising edge of HSYSCLK.  
I
I
I
HRSIG  
O
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
High Speed Bus System Sync  
HSSYNC  
I/O  
This input establishes the frame boundary for the multiplexed high-speed bus.  
This signal is sampled on the falling edge of HSYSCLK.  
Status Signals  
ROCD[4:1]  
O
O
O
O
Receive Out of Cell Delineation  
This output will be high when the cell processor is in an Out of Cell Delineation  
state.  
RLCD[4:1]  
Receive Loss of Cell Delineation  
This output will be high when the cell processor has been in an Out of Cell  
Delineation condition for a programmed number of cells.  
Receive Loss Of Frame / Loss Of Transmit Clock  
This output is user selectable to be high during either a loss of synchronization or  
loss of transmit clock.  
RLOF/LOTC[4:1]  
RLOS[4:1]  
Receive Loss Of Signal  
This output will be high during a loss of signal at RTIP and RRING.  
Microcontroller Interface Signals  
ADDR[12:0]  
DATA[7:0]  
CS  
I
I/O  
I
Address Bus ADDR[12:0]  
Data Bus DATA[7:0]  
Chip Select  
CS: Must be low to read or write to the device. CS is an active-low signal. This  
signal is used for both the parallel port and the serial port modes.  
Write Input(Read/Write)  
Read Input-Data Strobe  
Bus Type Select  
I
I
I
WR(R/W)  
RD(DS)  
BTS  
This bit selects the processor interface mode of operation.  
0 = Multiplexed  
1 = Non-multiplexed  
INT  
O
I
Interrupt  
INT: Flags host controller during events, alarms, and conditions defined in the status  
registers. Active-low open-drain output.  
JTAG Signals  
JTRST  
JTAG Reset (active low)  
This input forces the JTAG controller logic into the reset state and forces the  
JTDO pin into high impedance when low. This pin should be low while power is  
applied and set high after the power is stable. The pin can be driven high or low  
for normal operation, but must be high for JTAG operation.  
JTAG Clock  
This clock input is typically a low frequency (less than 10 MHz) 50% duty cycle  
clock signal.  
JTAG Mode Select (with pullup)  
JTCLK  
JTMS  
JTDI  
I
I
This input signal is used to control the JTAG controller state machine and is  
sampled on the rising edge of JTCLK.  
JTAG Data Input (with pullup)  
I
This input signal is used to input data into the register that is enabled by the JTAG  
controller state machine and is sampled on the rising edge of JTCLK.  
JTAG Data Output  
JTDO  
O
This output signal is the output of an internal scan shift register enabled by the  
JTAG controller state machine and is updated on the falling edge of JTCLK. The  
pin is in the high impedance mode when a register is not selected or when the  
JTRST signal is high. The pin goes into and exits the high impedance mode after  
the falling edge of JTCLK  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Network Interface Signals  
RRING[4:1]  
I
Receive Ring  
Analog input for clock recovery circuitry. This pin connects via a 1:1 transformer to  
the network. See Line Interface Unit for details.  
Receive Tip  
RTIP[4:1]  
I
Analog input for clock recovery circuitry. This pin connects via a 1:1 transformer to  
the network. See Line Interface Unit for details.  
Transmit Ring  
TRING[4:1]  
O
Analog line driver output. This pin connects via a 1:2 step-up transformer to the  
network. See Line Interface Unit for details.  
STRING[4:1]  
TTIP[4:1]  
O
O
Secondary Transmit Ring  
Analog line driver output. Internally connected to TRING.  
Transmit Tip  
Analog line driver output. This pin connects via a 1:2 step-up transformer to the  
network. See Line Interface Unit for details.  
STTIP[4:1]  
TXENABLE  
O
I
Secondary Transmit Tip  
Analog line driver output. Internally connected to TTIP.  
Transmit High Impedance Enable  
When high, TTIP and TRING will be placed into a high impedance state.  
Backplane UTOPIA/POS-PHY Signals  
RSCLK  
I
Receive System Interface Clock  
This signal is used to sample or update the other receive system interface signals.  
RSCLK has a maximum frequency of 52 MHz.  
RDAT[15:0]  
O
Receive System Interface Data Bus  
This 16-bit data bus is used to transfer cell/packet data to the ATM/Link layer  
device. This bus is updated on the rising edge of RSCLK.  
In 16-bit mode, RDAT15 is the MSB, RDAT0 is the LSB  
In 8-bit mode, RDAT7 is the MSB, RDAT0 is the LSB, and RDAT[15:8] are held  
low.  
RPAR  
O
I
Receive System Interface Parity  
This signal indicates the parity on the data bus. This signal is updated on the  
rising edge of RSCLK.  
RADR[4:0]  
Receive System Interface Address Bus  
This 5-bit address bus is used by the ATM/Link layer device to select a specific  
port. RADR4 is the MSB and RADR0 is the LSB. This bus is sampled on the rising  
edge of RSCLK.  
In POS-PHY Level 3 mode, this bus is ignored.  
I
Receive System Interface Enable  
REN  
This signal is used by the ATM/Link device to control the transfer of cell/packet  
data on the RDAT bus. If REN is high, no transfer occurs. If REN is low, a transfer  
occurs. This signal is sampled on the rising edge of RSCLK.  
26 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive System Interface Direct Cell/Packet Available  
RDXA[4:2]  
O
This signal is used to indicate when the associated port can send data to the  
ATM/Link layer device. This signal is updated on the rising edge of RSCLK.  
In UTOPIA mode, RDXA goes high when the associated port has more than a  
programmable number of ATM cells ready for transfer ("almost empty" level).  
RDXA goes low when the associated port does not have a complete ATM cell  
ready for transfer.  
In POS-PHY Level 2 mode, RDXA goes high when the associated port contains  
more data than the "almost empty" level or has an end of packet ready for  
transfer. RDXA goes low when the associated port does not have an end of  
packet ready for transfer and is "almost empty".  
In POS-PHY Level 3 mode, this signal is held low.  
RDXA[1] / RPXA /  
RSX  
O
Receive Direct cell/packet Available [1] / Polled cell/packet Available / Start of  
Transfer (tri-state)  
This signal is tri-state when global reset is applied.  
RDXA[1]: This signal is active in UTOPIA L2, UTOPIA L3 or POS-PHY L2 modes  
when direct status mode is selected. It is used to indicate when port 1 can send  
data to the ATM/Link layer device. This signal is updated on the rising edge of  
RSCLK.  
In UTOPIA L2 or UTOPIA L3 modes, RDXA goes high when port 1 has more than  
a programmable number of ATM cells ready for transfer ("almost empty" level).  
RDXA goes low when the associated port does not have a complete ATM cell  
ready for transfer.  
In POS-PHY L2 mode, RDXA goes high when port 1 contains more data than the  
"almost empty" level or has an end of packet ready for transfer. RDXA goes low  
when the associated port does not have an end of packet ready for transfer and is  
"almost empty".  
RPXA: (Reset default) This signal is active in UTOPIA L2, UTOPIA L3, or POS-  
PHY L2 modes when polled status mode is selected. It is used to indicate when the  
polled port, as selected by RADR[4:0], can send data to the ATM/Link layer device.  
This signal is updated on the rising edge of RSCLK.  
In UTOPIA L2 or UTOPIA L3 modes, RPXA goes high when the polled port has  
more than a programmable number of ATM cells ready for transfer ("almost empty"  
level). RPXA goes low when the polled port does not have a complete ATM cell  
ready for transfer.  
In POS-PHY L2 mode, RPXA goes high when the polled port contains more data  
than the "almost empty" level or has an end of packet ready for transfer. RPXA  
goes low when the port does not have an end of packet ready for transfer and is  
"almost empty".  
In UTOPIA L2 (reset default) or POS-PHY L2 modes, this signal is driven when  
one of the ports is being polled, and is tri-stated when none of the ports is being  
polled or when data path reset is active.  
In UTOPIA L3 mode this signal is driven.  
RSX: This signal is active in POS-PHY L3 modes and indicates the start of a data  
transfer. This signal is updated on the rising edge of RSCLK.  
RSX goes high immediately before the start of data transfer to indicate that the in-  
band port address is present on RDATA. RSX goes high when the value of  
RDATA is the address of the receive port from which data is to be transferred.  
When RSX goes low, all subsequent transfers will be from the port specified by  
the in-band address. When RSX is high, RVAL must be low. This signal is always  
driven in POS-PHY L3 mode.  
RSOX  
O
Receive System Interface Start Of Cell/Packet  
This signal is used to indicate the first transfer of a cell/packet. This signal is  
updated on the rising edge of RSCLK.  
In UTOPIA mode, RSOX is used to indicate the first transfer of a cell.  
In POS-PHY mode, RSOX is used to indicate the first transfer of a packet.  
27 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive System Interface End Of Packet  
This signal is used to indicate the last transfer of a packet. This signal is updated  
on the rising edge of RSCLK.  
In UTOPIA mode, this signal is held low.  
Receive System Interface Data Valid  
REOP  
RVAL  
O
O
This signal is used to indicate the validity of a receive data transfer. When RVAL is  
high, the receive data bus (RDAT, RPAR, RSOX, REOP, RMOD, and RERR) is  
valid and a packet data transfer occurs. When RVAL is low, the receive data bus  
is invalid and a data transfer does not occurs. This signal is updated on the rising  
edge of RSCLK.  
RVAL goes high when a port is selected for packet data transfer and the port has  
a programmable size block of data or an end of packet ready for transfer. In POS-  
PHY Level 2 mode, RVAL goes low if the selected port is empty, at the end of a  
packet, or when REN is deasserted. Once RVAL goes low, it will remain low until  
REN is deasserted.  
In POS-PHY Level 3 mode, RVAL goes low if the selected port is empty or at the  
end of a packet if the minimum deassertion time is greater than zero. RVAL will  
remain deasserted for the programmable minimum deassertion time.  
In UTOPIA mode, this signal is held low.  
RMOD  
O
Receive System Interface Data Bus Modulus  
This signal is used to indicate the number of valid bytes on the RDAT bus.  
RMOD = 0  
RMOD = 1  
RDAT[15:0] valid  
RDAT[15:8] valid  
This signal is updated on the rising edge of RSCLK. RMOD is only valid when  
REOP is high.  
In UTOPIA or 8-bit POS-PHY mode, this signal is held low.  
RERR  
O
Receive System Interface Packet Error  
This signal is used to indicate that the current packet is errored. When RERR is  
high, the current packet should be aborted. This signal is updated on the rising  
edge of RSCLK. RERR is only valid when REOP is high.  
In UTOPIA mode, this signal is held low.  
TSCLK  
I
I
Transmit System Interface Clock  
This signal is used to sample or update the other transmit system interface  
signals.  
TSCLK has a maximum frequency of 52 MHz.  
Transmit System Interface Data Bus  
TDAT[15:0]  
This 16-bit data bus is used to transfer cell/packet data from the ATM/Link layer  
device. This bus is sampled on the rising edge of TSCLK.  
In 16-bit mode, TDAT15 is the MSB, TDAT0 is the LSB.  
In 8-bit mode, TDAT7 is the MSB, TDAT0 is the LSB, and TDAT[15:8] are held  
low.  
TPAR  
I
I
Transmit System Interface Parity  
This signal indicates the parity on the data bus. This signal is sampled on the  
rising edge of TSCLK.  
TADR[4:0]  
Transmit System Interface Address Bus  
This 5-bit address bus is used by the ATM/Link layer device to select a specific  
port. TADR7 is the MSB and TADR0 is the LSB. This bus is sampled on the rising  
edge of TSCLK.  
I
Transmit System Interface Enable  
TEN  
This signal is used by the ATM/Link device to control the transfer of cell/packet  
data on the TDAT bus. If TEN is high, no transfer occurs. If TEN is low, a transfer  
occurs. This signal is sampled on the rising edge of TSCLK.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Transmit System Interface Direct Cell/Packet Available  
TDXA[4: 2]  
O
O
This signal is used to indicate when the associated port can accept data from the  
ATM/Link layer device. This signal is updated on the rising edge of TSCLK.  
In UTOPIA mode, TDXA goes high when the associated port can accept the  
transfer of more than a programmable number of ATM cells. TDXA goes low when  
the associated port cannot accept the transfer of a complete ATM cell.  
In POS-PHY mode, TDXA goes high when the associated port can store more  
data than the "almost full" level. TDXA goes low when the associated port is full.  
Transmit Direct cell/packet Available [1] / Polled cell/packet Available (tri-  
state)  
TDXA[1] / TPXA  
This signal is tri-state when global reset is applied.  
TDXA[1]: When direct status mode is selected, this signal is used to indicate when  
port 1 can accept data from the ATM/Link layer device. This signal is updated on  
the rising edge of TSCLK.  
In UTOPIA L2 or UTOPIA L3 modes, TDXA goes high when port 1 can accept the  
transfer of more than a programmable number of ATM cells. TDXA goes low when  
port 1 cannot accept the transfer of a complete ATM cell.  
In POS-PHY L2 or POS-PHY L3 modes, TDXA goes high when port 1 can store  
more data than the "almost full" level. TDXA goes low when port 1 is full.  
TPXA: (reset default) When polled status mode is selected, this signal is used to  
indicate when the polled port, as selected by TADR[4:0], can accept data from the  
ATM/Link layer device. This signal is updated on the rising edge of TSCLK.  
In UTOPIA L2 or UTOPIA L3 modes, TPXA goes high when the polled port can  
accept the transfer of more than a programmable number of ATM cells. TPXA goes  
low when the polled port cannot accept the transfer of a complete ATM cell.  
In POS-PHY L2 or POS-PHY L3 modes, TPXA goes high when the polled port can  
store more data than the "almost full" level. TPXA goes low when the polled port is  
full.  
In UTOPIA L2 (reset default) or POS-PHY L2 modes, this signal is driven when  
one of the ports is being polled, and is tri-stated when none of the ports is being  
polled or when data path reset is active.  
In UTOPIA L3 or POS-PHY L3 modes, this signal is driven.  
Note: Polled status mode and direct status mode is selected by the GCR1.DIREN  
bit.  
TSOX  
TSPA  
I
Transmit System Interface Start Of Cell/Packet  
This signal is used to indicate the first transfer of a cell/packet. This signal is  
sampled on the rising edge of TSCLK.  
In UTOPIA mode, TSOX indicates the first transfer of a cell.  
In POS-PHY mode, TSOX indicates the first transfer of a packet.  
Transmit System Interface Selected Packet Available  
O
This signal is used to indicate the selected port can accept data from the Link  
layer device. TSPA goes high when a port is selected for transfer and it can  
accept more data than the "almost full" level. TSPA goes low when the selected  
port is "full" or no port is selected. This signal is updated on the rising edge of  
TSCLK.  
In UTOPIA mode, this signal is held low.  
TEOP  
I
Transmit System Interface End Of Packet  
This signal is used to indicate the last transfer of a packet. This signal is sampled  
on the rising edge of TSCLK.  
In UTOPIA mode, this signal is ignored.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Transmit System Interface Start of Transfer  
This signal indicates the start of a data transfer. TSX goes high goes high  
immediately before the start of data transfer to indicate that the in-band port  
address is present on TDAT. TSX goes high when the value of TDAT is the  
address of the transmit port to which data is to be transferred. When TSX goes  
low, all subsequent transfers will be to the port specified by the in-band address.  
This signal is sampled on the rising edge of TSCLK. TSX is only valid when TEN is  
high.  
TSX  
I
I
I
In UTOPIA or POS-PHY Level 2 mode, this signal is ignored.  
Transmit System Interface Data Bus Modulus  
This signal indicates the number of valid bytes on the TDAT bus.  
TMOD  
TMOD = 0  
TMOD = 1  
TDAT[15:0] valid  
TDAT[15:8] valid  
This signal is sampled on the rising edge of TSCLK. TMOD is only valid when  
TEOP is high.  
In UTOPIA or 8-bit POS-PHY mode, this signal is ignored.  
TERR  
Transmit System Interface Packet Error  
This signal indicates that the current packet is errored. When TERR is high, the  
current packet should be aborted. This signal is sampled on the rising edge of  
TSCLK. TERR is only valid when TEOP is high.  
In UTOPIA mode, this signal is ignored.  
Clock Signals  
I
I
Reset (active low)  
RESET  
This signal resets all the internal processor registers and logic when low. This pin  
should be low while power is applied and set high after the power is stable. This  
is an asynchronous input.  
MCLK  
Master Clock Input  
A (50ppm) clock source. This clock is used internally for both clock/data recovery  
and for the jitter attenuator for both T1 and E1 modes. The clock rate can be  
16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz. When using the DS26556 in T1-  
only operation a 1.544MHz (50ppm) clock source can be used.  
Backplane Clock  
BPCLK  
O
This output clock is generated using the REFCLK signal as its source or one of  
the RCLKO[4:1] signals as its source and can be a 2.048 MHz, 4.096 MHz, or  
8.192 MHz. This clock can be externally wired to HSYSCLK.  
Reference Clock  
REFCLK  
I/O  
This clock is used as the reference source for the BPCLK either as an output or as  
an input. As an input, the input frequency must be either 1.544 MHz or 2.048  
MHz. The mode of operation is controlled by the GCCR Register.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
6 DEVICE CONFIGURATION  
A typical, high-level device configuration scenario is shown below. There are many more aspects to setting up the  
device as described in this data sheet. This is intended to give the user a general procedure for setting up the  
DS26556.  
1) Configure Port Network Interface Mode (per-port): This step determines how each port will interface to the  
physical network  
i) T1  
(a) ESF  
(b) D4  
ii) E1  
(a) FAS only  
(b) FAS + CRC4  
(c) FAS + CAS  
(d) FAS + CRC4 + CAS  
iii) J1  
(a) ESF  
(b) D4  
2) Configure Cell/Packet Interface Mode (global): This step places the Cell/Packet interface into the ATM Cell  
mode or IP Packet mode. This selection is global to all ports.  
i) Cell or Packet mode  
(1) Cell  
(2) Packet  
ii) Select Cell/Packet backplane bus configuration  
(1) 8 bits  
(2) 16 bits  
3) Configure Port Backplane Interface (per-port): This step determines how each port will be interfaced to the  
three backplane types available (Cell/Packet, TDM, High Speed Multiplexed TDM).  
i) Pure Cell/packet  
(a) Map all channels to Cell/Packet Interface  
ii) Fractional Cell/Packet  
(a) Select channels to be mapped to Cell/Packet interface  
iii) Mixed TDM and Cell/Packet  
(a) Select channels to be mapped to Cell/Packet interface  
(b) Channels not mapped to Cell/Packet interface are available on TDM port. NOTE: All  
channels are actually available at the TDM ports. Signals at RCHMRK and TCHMRK  
pins indicate mapping status of each channel.  
iv) High Speed Multiplexed TDM Bus  
4) Configure Controller Interface  
i) Enable appropriate interrupts  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
7 FUNCTIONAL PIN TIMING  
7.1 Receiver Functional Timing Diagrams  
Figure 7-1 Receive TDM Signals  
CHANNEL  
RCLK  
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22  
RSER  
RSYNC  
RCHMRK1  
RCHMRK2  
RCHMRK3  
Notes:  
1 RCHMRK in cell/packet mapping indicator mode  
2 RCHMRK in channel marking mode  
3 RCHMRK in gapped clock mode  
Figure 7-2 Receive TDM Signals, Details  
CHANNEL 1  
CHANNEL 2  
RCLK  
RSER LSB MSB  
RSYNC  
LSB MSB  
RCHMRK1  
RCHMRK2  
RCHMRK3  
Notes:  
1 RCHMRK in cell/packet mapping indicator mode  
2 RCHMRK in channel marking mode  
3 RCHMRK in gapped clock mode  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
7.2 Transmitter Functional Timing Diagrams  
Figure 7-3 Transmit TDM Signals  
CHANNEL  
TCLK  
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22  
TSERI  
TSYNC  
TCHMRK1  
TCHMRK2  
TCHMRK3  
Notes:  
1 TCHMRK in cell/packet mapping indicator mode  
2 TCHMRK in channel marking mode  
3 TCHMRK in gapped clock mode  
Figure 7-4 Transmit TDM Signals, Details  
CHANNEL 1  
CHANNEL 2  
TCLK  
TSERI  
TSYNC  
LSB MSB  
LSB MSB  
TCHMRK1  
TCHMRK2  
TCHMRK3  
Notes:  
1 TCHMRK in cell/packet mapping indicator mode  
2 TCHMRK in channel marking mode  
3 TCHMRK in gapped clock mode  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-5 Two Port High Speed TDM Bus  
PORT 2  
PORT 1  
PORT 2  
PORT 1  
PORT 2  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
HSSYNC  
HTDATA  
HRDATA  
HTSIG  
HRSIG  
PORT 2  
PORT 1  
CHANNELS 1-32  
CHANNELS 1-32  
BIT DETAIL  
HSYSCLK  
HSSYNC  
PORT 1, CHANNEL 2  
PORT 2, CHANNEL 32  
PORT 2, CHANNEL 32  
PORT 1, CHANNEL 1  
PORT 1, CHANNEL 1  
MSB  
LSB  
LSB  
LSB MSB  
HRDATA / HTDATA  
HRSIG / HTSIG  
PORT 1, CHANNEL 2  
A
B
C/A D/B  
A
B
C/A D/B  
A
B
C/A D/B  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-6 Four Port High Speed TDM Bus  
PORT 4  
PORT 1  
PORT 2  
PORT 3  
PORT 4  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
CHANNELS 1-32  
HSSYNC  
HTDATA  
HRDATA  
HTSIG  
HRSIG  
PORT 4  
PORT 1  
CHANNELS 1-32  
CHANNELS 1-32  
BIT DETAIL  
HSYSCLK  
HSSYNC  
PORT 1, CHANNEL 2  
PORT 4, CHANNEL 32  
PORT4, CHANNEL 32  
PORT 1, CHANNEL 1  
PORT 1, CHANNEL 1  
MSB  
LSB  
LSB  
LSB MSB  
HRDATA / HTDATA  
HRSIG / HTSIG  
PORT 1, CHANNEL 2  
A
B
C/A D/B  
A
B
C/A D/B  
A
B
C/A D/B  
7.3 UTOPIA/POS-PHY/SPI-3 System Interface Functional Timing  
7.3.1 UTOPIA Level 2 Functional Timing  
Figure 7-7 shows a multidevice transmit-interface multiple cell transfer to different PHY devices. On clock edge 2,  
the ATM device places address ‘00h’ on the address bus (which is mapped to Port 1). PHY device '1' (Port 1)  
indicates to the ATM device that it can accept cell data by asserting TDXA[1]. On clock edge 4, the ATM device  
selects PHY device '1'. On clock edge 5, the ATM device starts a cell transfer to PHY device '1' by asserting TEN,  
placing the first byte of cell data on TDATA, and asserting TSOX to indicate the transfer of the first byte of the cell.  
On clock edge 6, the ATM device deasserts TSOX as it continues to place additional bytes of the cell on TDATA..  
On clock edge 13, PHY device ‘2’ asserts TDXA[2] to indicate to the ATM device that it is ready to accept cell data.  
On clock edge 15, PHY device '1’ indicates that it cannot accept the transfer of a complete cell by deasserting  
TDXA[1]. On clock edge 16, the ATM device deselects PHY device '1' and selects PHY device '2' by deasserting  
TEN and placing PHY device '2's address on TADR. On clock edge 17, the ATM device starts the transfer of a cell  
to PHY device '2' by asserting TEN, placing the first byte of cell data on TDATA, and asserting TSOX to indicate  
the transfer of the first byte of the cell. On clock edge 18, the ATM device deasserts TSOX as it continues to place  
additional bytes of the cell on TDATA.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-7 UTOPIA Level 2 Transmit Cell Transfer Direct Mode  
TCLK  
TADR  
TDXA[1]  
TDXA[2]  
TDXA[3]  
00h  
01h  
TDXA[4]  
TEN  
TDATA  
H1 H2 H3  
P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3 H4  
TSOX  
Transfer  
Cell To:  
PORT 1  
PORT 2  
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-8 shows a multidevice transmit-interface multiple cell transfer to different PHY devices. On clock edge 2,  
the ATM device places address ‘00h’ on the address bus (which is mapped to Port 1). PHY device '1' (Port 1)  
indicates to the ATM device that it has a complete cell to send by asserting RDXA[1]. On clock edge 4, the ATM  
device selects PHY device '1'. On clock edge 5, the ATM device asserts REN. On clock edge 6, the PHY device ‘1’  
starts a cell transfer to the ATM device by placing the first byte of cell data on RDATA, and asserting RSOX to  
indicate the transfer of the first byte of the cell. On clock edge 7, the PHY device deasserts RSOX as it continues to  
place additional bytes of the cell on RDATA. On clock edge 13, PHY device ‘2’ asserts RDXA[2] to indicate to the  
ATM device that it is ready to send a cell. On clock edge 15, PHY device '1’ indicates that it cannot transfer a  
complete cell by deasserting RDXA[1]. On clock edge 16, the ATM device deselects PHY device '1' and selects  
PHY device '2' by deasserting REN and placing PHY device '2's address on RADR. On clock edge 17, the ATM  
device asserts REN. On clock edge 18, PHY device ‘2’ (Port 2) starts the transfer of a cell to the ATM device by  
placing the first byte of cell data on RDATA, and asserting RSOX to indicate the transfer of the first byte of the cell.  
On clock edge 18, the PHY device deasserts RSOX as it continues to place additional bytes of the cell on RDATA.  
Figure 7-8 UTOPIA Level 2 Receive Cell Transfer Direct Mode  
RSCLK  
RADR  
RDXA[1]  
RDXA[2]  
RDXA[3]  
00h  
01h  
RDXA[4]  
REN  
H1 H2 H3  
RDATA  
P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3  
RSOX  
Transfer  
Cell From:  
PORT 1  
PORT 2  
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
36 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-9 shows a multidevice transmit-interface multiple cell transfer to different PHY devices. On clock edge 2,  
the ATM device polls PHY device 'N'. On clock edge 3, PHY device 'N' indicates to the ATM device that it can  
accept cell data by asserting TPXA. On clock edge 4, the ATM device selects PHY device 'N'. On clock edge 5, the  
ATM device starts a cell transfer to PHY device 'N' by asserting TEN, placing the first byte of cell data on TDATA,  
and asserting TSOX to indicate the transfer of the first byte of the cell. On clock edge 6, the ATM device deasserts  
TSOX as it continues to place additional bytes of the cell on TDATA. On clock edge 6, the ATM device also polls  
PHY device 'O'. On clock edge 7, PHY device 'O' indicates that it can accept the transfer of a complete cell. On  
clock edge 14, the ATM device polls PHY device 'N'. On clock edge 15, PHY device 'N' indicates that it cannot  
accept the transfer of a complete cell. On clock edge 16, the ATM device deselects PHY device 'N' and selects  
PHY device 'O' by deasserting TEN and placing PHY device 'O's address on TADR. On clock edge 17, the ATM  
device starts the transfer of a cell to PHY device 'O' by asserting TEN, placing the first byte of cell data on TDATA,  
and asserting TSOX to indicate the transfer of the first byte of the cell. On clock edge 18, the ATM device  
deasserts TSOX as it continues to place additional bytes of the cell on TDATA.  
Figure 7-9 UTOPIA Level 2 Transmit Multiple Cell Transfer Polled Mode  
TCLK  
TADR  
TPXA  
TEN  
M
1F  
M
N
1F  
N
N
1F  
N
O
1F  
O
1F  
P
L
1F  
M
1F  
N
1F  
N
O
1F  
P
1F  
P
L
L
M
O
H1 H2  
TDATA  
TSOX  
H3  
P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3 H4  
N
O
Transfer  
Cell To:  
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-10 shows a multidevice receive-interface multiple cell transfer from different PHY devices. On clock edge  
2, the ATM device polls PHY device 'N'. On clock edge 3, PHY device 'N' indicates to the ATM device that it has a  
complete cell ready for transfer by asserting RPXA. On clock edge 4, the ATM device selects PHY device 'N'. On  
clock edge 5, the ATM device asserts REN. On clock edge 6, PHY device 'N' starts a cell transfer by placing the  
first byte of cell data on RDATA, and asserting RSOX to indicate the transfer of the first byte of the cell. On clock  
edge 7, PHY device 'N' deasserts RSOX as it continues to place additional bytes of the cell on RDATA. On clock  
edge 12, the ATM device polls PHY device 'O'. On clock edge 13, PHY device 'O' indicates to the ATM device that  
it has a complete cell ready for transfer by asserting RPXA. On clock edge 16, the ATM device deselects PHY  
device 'N' and selects PHY device 'O' by deasserting REN and placing PHY device 'O's address on RADR. On  
clock edge 17, the ATM device asserts REN and PHY device 'N' stops transferring cell data and tri-states its  
RDATA and RSOX outputs. On clock edge 18, PHY device 'O' starts a cell transfer by placing the first byte of cell  
data on RDATA, and asserting RSOX to indicate the transfer of the first byte of the cell. On clock edge 19, PHY  
device 'O' deasserts RSOX as it continues to place additional bytes of the cell on RDATA.  
Figure 7-10 UTOPIA Level 2 Receive Multiple Cell Transfer Polled Mode  
RCLK  
M
1F  
M
N
1F  
N
N
1F  
N
O
1F  
O
1F  
L
M
1F  
M
O
1F  
O
P
1F  
P
O
1F  
O
N
1F  
N
P
RADR  
RPXA  
REN  
H1 H2  
P41 P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3  
RDATA  
RSOX  
Transfer  
Cell From:  
N
O
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-11 shows a multidevice receive-interface unexpected multiple cell transfer. Prior to clock edge 1, the cell  
transfer was started. On clock edge 4, since no other PHY device has a cell ready for transfer, the ATM device  
assumes another cell transfer from PHY device 'N' and leaves REN asserted. On clock edge 5, PHY device 'N'  
stops transferring cell data and indicates that it does not have another cell ready for transfer by not asserting  
RSOX. On clock edge 6, the ATM device deasserts REN to end the cell transfer process. At the same time, PHY  
device 'N' indicates to the ATM device that it now has a complete cell ready for transfer by placing the first byte of  
cell data on RDAT, and asserting RSOX to indicate the transfer of the first byte of the cell. On clock edge 7, PHY  
device 'N' tri-states its RDAT and RSOX outputs because REN is deasserted. On clock edge 8, the ATM device  
selects PHY device 'N'. On clock edge 9, the ATM device asserts REN. On clock edge 10, PHY device 'N'  
continues the cell transfer by placing the second byte of cell data on RDAT, and deasserting RSOX.  
Figure 7-11 UTOPIA Level 2 Receive Unexpected Multiple Cell Transfer  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
RCLK  
RADR  
RPXA  
REN*  
RDAT  
RSOX  
L
1F  
L
M
1F  
M
N
1F  
N
O
1F  
O
N
1F  
N
P
1F  
P
L
1F  
L
M
1F  
M
O
1F  
O
P
1F  
P
L
P45 P46 P47 P48  
X
H1  
H2 H3 H4  
P1  
P2  
P3  
P4  
P5  
P6  
P7  
P8  
N
Transfer  
Cell From:  
N
N
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
7.3.2 UTOPIA Level 3 Functional Timing  
Figure 7-12 shows a multiport transmit-interface multiple cell transfer to different PHY devices. PHY port '1', ‘3’, ‘4’  
indicate to the ATM device that they can accept cell data by asserting the TDXA[n]. On clock edge 2, the ATM  
device selects PHY port '1' by putting address ‘00h’ on the address bus. On clock edge 5, the ATM device starts a  
cell transfer to PHY port '1' by asserting TEN, placing the first byte of cell data on TDATA, and asserting TSOX to  
indicate the transfer of the first byte of the cell. On clock edge 6, the ATM device deasserts TSOX as it continues to  
place additional bytes of the cell on TDATA. On clock edge 13, PHY port ‘2’ asserts TDXA[2] to indicate it is ready  
to accept a cell. On clock edge 15, PHY port ‘1’ deasserts TDXA[1] to indicate to the ATM device that it does not  
have the availability to receive another complete cell. On clock edge 16, the ATM device selects PHY port '2' by  
deasserting TEN and placing PHY port '2's address on TADR. On clock edge 17, the ATM device starts the  
transfer of a cell to PHY port '2' by asserting TEN, placing the first byte of cell data on TDATA, and asserting TSOX  
to indicate the transfer of the first byte of the cell. On clock edge 18, the ATM device deasserts TSOX as it  
continues to place additional bytes of the cell on TDATA.  
Figure 7-12 UTOPIA Level 3 Transmit Multiple Cell Transfer Direct Mode  
TSCLK  
TADR  
TDXA[1]  
TDXA[2]  
TDXA[3]  
00h  
01h  
TDXA[4]  
TEN  
TDATA  
H1 H2 H3  
P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3 H4  
TSOX  
Transfer  
Cell To:  
PORT 1  
PORT 2  
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-13 shows a multiport transmit-interface multiple cell transfer to different PHY devices. On clock edge 1,  
the ATM device polls PHY port 'N'. On clock edge 3, PHY port 'N' indicates to the ATM device that it can accept  
cell data by asserting TPXA. On clock edge 5, the ATM device selects PHY port 'N'. On clock edge 6, the ATM  
device starts a cell transfer to PHY port 'N' by asserting TEN, placing the first byte of cell data on TDATA, and  
asserting TSOX to indicate the transfer of the first byte of the cell. On clock edge 7, the ATM device deasserts  
TSOX as it continues to place additional bytes of the cell on TDATA. On clock edge 11, the ATM device polls PHY  
port 'M'. On clock edge 12, the ATM device polls PHY port 'N'. On clock edge 13, PHY port 'M' indicates that it can  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
accept the transfer of a complete cell. On clock edge 14, PHY port 'N' indicates that it cannot accept the transfer of  
a complete cell. On clock edge 16, the ATM device deselects PHY port 'N' and selects PHY port 'M' by deasserting  
TEN and placing PHY port 'M's address on TADR. On clock edge 17, the ATM device starts the transfer of a cell to  
PHY port 'M' by asserting TEN, placing the first byte of cell data on TDATA, and asserting TSOX to indicate the  
transfer of the first byte of the cell. On clock edge 18, the ATM device deasserts TSOX as it continues to place  
additional bytes of the cell on TDATA.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-13 UTOPIA Level 3 Transmit Multiple Cell Transfer Polled Mode  
TCLK  
TADR  
TPXA  
TEN  
M
K
N
L
O
M
P
N
Q
O
N
P
R
Q
J
K
R
L
J
M
K
N
L
O
M
P
N
Q
O
M
P
R
Q
J
K
R
L
J
X
X
TDATA  
X
X
X
X
X
X
H1  
H2  
H3  
P43 P44 P45 P46 P47 P48  
X
H1  
H2  
H3  
P1  
TSOX  
Transfer  
Cell To:  
N
10  
M
1
2
3
4
5
6
7
8
9
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
Figure 7-14 shows a multiport receive-interface multiple cell transfer from different PHY ports. On clock edge 3,  
PHY port 'N' indicates to the ATM device that it has a complete cell ready for transfer by asserting RPXA. On clock  
edge 5, the ATM device selects PHY port 'N'. On clock edge 6, the ATM device indicates to PHY port 'N' that it is  
ready to accept a complete cell transfer by asserting REN. On clock edge 8, PHY port 'N' starts a cell transfer by  
placing the first byte of cell data on RDATA, and asserting RSOX to indicate the transfer of the first byte of the cell.  
On clock edge 9, PHY port 'N' deasserts RSOX as it continues to place additional bytes of the cell on RDAT. On  
clock edge 11, the ATM device polls PHY device 'N'. On clock edge 12, PHY port 'M' indicates to the ATM device  
that it has a complete cell ready for transfer by asserting RPXA. On clock edge 12, PHY port 'N' indicates to the  
ATM device that it does not have a complete cell ready for transfer by deasserting RPXA. On clock edge 15, the  
ATM device deselects PHY port 'N' and selects PHY port 'M' by deasserting REN and placing PHY port 'M's  
address on RADR. On clock edge 16, the ATM device asserts REN. On clock edge 17, PHY port 'N' stops  
transferring cell data. On clock edge 18, PHY port 'M' starts a cell transfer by placing the first byte of cell data on  
RDATA, and asserting RSOX to indicate the transfer of the first byte of the cell. On clock edge 19, PHY port 'M'  
deasserts RSOX as it continues to place additional bytes of the cell on RDATA.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-14 UTOPIA Level 3 Receive Multiple Cell Transfer Direct Mode  
RSCLK  
RADR  
RDXA[1]  
RDXA[2]  
RDXA[3]  
00h  
01h  
RDXA[4]  
REN  
RDATA  
H1 H2 H3  
P42 P43 P44 P45 P46 P47 P48  
H1 H2 H3  
RSOX  
Transfer  
Cell From:  
PORT 1  
PORT 2  
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-15 shows a multiport receive-interface multiple cell transfer from different PHY ports. On clock edge 1, the  
ATM device polls PHY port 'N'. On clock edge 3, PHY port 'N' indicates to the ATM device that it has a complete  
cell ready for transfer by asserting RPXA. On clock edge 5, the ATM device selects PHY port 'N'. On clock edge 6,  
the ATM device indicates to PHY port 'N' that it is ready to accept a complete cell transfer by asserting REN. On  
clock edge 8, PHY port 'N' starts a cell transfer by placing the first byte of cell data on RDATA, and asserting  
RSOX to indicate the transfer of the first byte of the cell. On clock edge 9, PHY port 'N' deasserts RSOX as it  
continues to place additional bytes of the cell on RDAT. On clock edge 11, the ATM device polls PHY device 'N'.  
On clock edge 12, PHY port 'M' indicates to the ATM device that it has a complete cell ready for transfer by  
asserting RPXA. On clock edge 12, PHY port 'N' indicates to the ATM device that it does not have a complete cell  
ready for transfer by deasserting RPXA. On clock edge 15, the ATM device deselects PHY port 'N' and selects  
PHY port 'M' by deasserting REN and placing PHY port 'M's address on RADR. On clock edge 16, the ATM device  
asserts REN. On clock edge 17, PHY port 'N' stops transferring cell data. On clock edge 18, PHY port 'M' starts a  
cell transfer by placing the first byte of cell data on RDATA, and asserting RSOX to indicate the transfer of the first  
byte of the cell. On clock edge 19, PHY port 'M' deasserts RSOX as it continues to place additional bytes of the cell  
on RDATA.  
Figure 7-15 UTOPIA Level 3 Receive Multiple Cell Transfer Polled Mode  
RCLK  
RADR  
RPXA  
REN  
M
K
N
L
O
P
Q
O
N
P
R
Q
J
K
R
L
J
N
L
O
P
Q
O
M
P
R
Q
J
K
R
L
J
M
K
M
N
N
M
N
M
RDAT  
X
X
X
X
X
X
X
X
H1 H2  
P43 P44 P45 P46 P47 P48  
X
H1 H2  
P1  
RSOX  
Transfer  
Cell From:  
N
M
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
7.3.3 POS-PHY Level 2 Functional Timing  
Figure 7-16 shows a multidevice transmit interface in byte transfer mode multiple packet transfer to different PHY  
ports. Prior to clock edge 1, the POS device started a packet transfer to PHY port '1'. On clock edge 2, PHY port '1'  
deasserts its TDXA to indicate to the POS device that it cannot accept any more data transfers. On clock edge 3,  
the POS device stops the packet transfer to PHY port '1', and starts a packet transfer to PHY port '2' by leaving  
TEN asserted, placing PHY port '2's address on TADR, placing the first byte of packet data on TDATA, and  
asserting TSOX to indicate the transfer of the first byte of the packet. On clock edge 7, PHY port '2' deasserts its  
TDXA to indicate to the POS device that it cannot accept any more data transfers. On clock edge 8, the POS  
device stops the packet transfer to PHY port '2', and resumes a packet transfer to PHY port '3'. On clock edge 12,  
PHY port '2' indicates to the POS device that it can accept a block of packet data by asserting its TDXA. Also, the  
POS device indicates it is transferring the last byte of packet data by asserting TEOP. On clock edge 13, the POS  
device ends the packet transfer to PHY port '3', and starts a packet transfer to PHY port '4'. On clock edge 15, PHY  
port '1' indicates to the POS device that it can accept a block of packet data. On clock edge 17, PHY port '4'  
deasserts its TDXA to indicate to the POS device that it cannot accept any more data transfers. On clock edge 18,  
the POS device stops the packet transfer to PHY port '4', and resumes a packet transfer to PHY port '1'.  
Figure 7-16 Transmit Multiple Packet Transfer to Different PHY ports (direct status mode)  
TCLK  
'1'  
'2'  
'3'  
'4'  
'1'  
TADR  
TDXA[1]  
TDXA[2]  
TDXA[3]  
TDXA[4]  
TEN  
TDATA  
P35  
P34  
P1  
P2  
P41 P42 P19 P20  
P63 P64 P1  
P2  
P49 P50 P36 P37 P38  
TSOX  
TEOP  
TERR  
Transfer  
To Port  
'1'  
1
'2'  
'3'  
'4'  
'1'  
19  
2
3
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
20  
Figure 7-17 shows a multidevice receive interface in byte transfer mode multiple packet transfer from different PHY  
ports/devices. Prior to clock edge 1, a packet data transfer was initiated from PHY port '1', and PHY ports '2', '3',  
and '4' indicated to the POS device that they have a block of packet data or an end of packet ready for transfer by  
asserting their RDXA. On clock edge 2, the POS device indicates to PHY port '1' that it cannot accept any more  
data transfers by removing its address from RADR, and indicates to PHY port '2' that it is ready to accept a block of  
packet data by placing its address on RADR and leaving REN asserted. On clock edge 3, PHY port '1' stops  
transferring packet data, and PHY port '2' starts a packet transfer by leaving RVAL asserted, placing the first byte  
of the packet on RDATA, and asserting RSOX to indicate that this is the first transfer of the packet. On clock edge  
4, PHY port '2' deasserts RSOX as it leaves RVAL asserted and continues to place additional bytes of the packet  
on RDATA. On clock edge 8, the POS device deasserts REN to indicate to PHY port '2' that it cannot accept any  
more data transfers. On clock edge 9, PHY port '2' ends the packet transfer process by deasserting RVAL and tri-  
stating its RVAL, RDATA, RSOX, REOP, and RERR outputs. And, the POS device indicates to PHY port '3' that it  
is ready to accept a block of packet data by placing its address on RADR and reasserting REN. On clock edge 10,  
PHY port '3' continues a packet transfer by asserting RVAL and placing the next byte of packet data on RDATA.  
On clock edge 14, PHY port '3' places the last byte of the packet on RDATA, and asserts REOP to indicate that  
this is the last transfer of the packet. On clock edge 15, PHY port '3' deasserts RVAL and REOP ending the packet  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
transfer process, as well as, deasserting RDXA to indicate that it does not have another block of packet data or an  
end of packet ready for transfer. On clock edge 16, the POS device indicates to PHY port '4' that it is ready to  
accept a block of packet data by placing its address on RADR and leaving REN asserted. On clock edge 17, PHY  
port '4' starts a packet transfer by leaving RVAL asserted, placing the first byte of the packet on RDATA, and  
asserting RSOX to indicate that this is the first transfer of the packet. On clock edge 18, PHY port '4' deasserts  
RSOX as it leaves RVAL asserted and continues to place additional bytes of the packet on RDATA.  
Figure 7-17 POS-PHY Level 2 Receive Multiple Packet Transfer from Different PHY  
Ports/Devices (direct status mode)  
RCLK  
'1'  
'2'  
1F  
'3'  
'4'  
RADR  
RDXA[1]  
RDXA[2]  
RDXA[3]  
RDXA[4]  
REN  
RVAL  
P35  
RDATA  
P34  
P1  
P2  
P41 P42 P43  
P19 P20  
P63 P64  
X
X
P1  
P2  
P3  
P4  
RSOX  
REOP  
RERR  
Transfer  
From PHY  
'1'  
1
'2'  
'3'  
12  
'4'  
19  
2
3
4
5
6
7
8
9
10  
11  
13  
14  
15  
16  
17  
18  
20  
Figure 7-18 shows a multidevice transmit interface in packet transfer mode multiple packet transfer to different  
PHY ports. On clock edge 2, the POS device polls PHY port 'N'. On clock edge 3, PHY port 'N' indicates to the  
POS device that it can accept a block of packet data by asserting TPXA. On clock edge 4, the POS device selects  
PHY port 'N'. On clock edge 5, the POS device starts a packet transfer to PHY port 'N' by asserting TEN, placing  
the first byte of packet data on TDATA, and asserting TSOX to indicate the transfer of the first byte of the packet.  
On clock edge 6, the POS device deasserts TSOX as it continues to place additional bytes of the packet on  
TDATA. And, PHY port 'N' drives its TSPA output high. On clock edge 10, the POS device polls PHY port 'M'. On  
clock edge 11, the POS device asserts TEOP to indicate the transfer of the last byte of the packet to PHY port 'N'  
and PHY port 'M' indicates to the POS device that it can accept a block of packet data by asserting TPXA. On clock  
edge 12, the POS device deasserts TEN to end the packet transfer process to PHY port 'N' and selects PHY port  
'M'. On clock edge 13, the POS device starts a packet transfer to PHY port 'M' by asserting TEN, placing the first  
byte of packet data on TDATA, and asserting TSOX to indicate the transfer of the first byte of the packet. And, PHY  
port 'N' tri-states its TSPA output. On clock edge 14, the POS device deasserts TSOX as it continues to place  
additional bytes of the packet on TDATA. And, PHY port 'M' drives its TSPA output high.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-18 POS-PHY Level 2 Transmit Multiple Packet Transfer to Different PHY Ports  
(polled status mode)  
TCLK  
TADR  
TPXA  
TSPA  
TEN  
1F  
M
N
X
1F  
N
N
X
1F  
N
O
1F  
O
1F  
L
M
1F  
M
M
X
1F  
M
N
1F  
N
O
1F  
O
P
1F  
P
L
X
X
P1  
P2  
P3  
P62 P63 P64  
P1  
P2  
P3  
P4  
P5  
P6  
P7  
P8  
TDAT  
TSOX  
TEOP  
TERR  
Transfer  
To PHY  
N
M
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-19 shows a multidevice receive interface in packet transfer mode multiple packet transfer. On clock edge  
2, the POS device polls PHY port 'N'. On clock edge 3, PHY port 'N' indicates to the POS device that it has a block  
of packet data or an end of packet ready for transfer by asserting RPXA. On clock edge 4, the POS device selects  
PHY port 'N'. On clock edge 5, the POS device indicates to PHY port 'N' that it is ready to accept a block of packet  
data by placing its address on RADR and asserting REN. On clock edge 6, PHY port 'N' starts packet transfer by  
asserting RVAL, placing the first byte of the packet on RDATA, and asserting RSOX to indicate that this is the first  
transfer of the packet. On clock edge 7, PHY port 'N' deasserts RSOX as it leaves RVAL asserted and continues to  
place additional bytes of the packet on RDATA. On clock edge 14, PHY port 'N' places the last byte of the packet  
on RDATA, and asserts REOP to indicate that this is the last transfer of the packet. On clock edge 15, PHY port 'N'  
deasserts RVAL and REOP ending the packet transfer process. On clock edge 16, the POS device deasserts REN  
and selects PHY port 'P'. On clock edge 17, PHY port 'N' tri-states its RVAL, RDATA, RSOX, REOP, and RERR  
outputs and the POS device indicates to PHY port 'P' that it is ready to accept a block of packet data by placing its  
address on RADR and asserting REN. On clock edge 18, PHY port 'P' starts packet transfer by asserting RVAL,  
placing the first byte of the packet on RDATA, and asserting RSOX to indicate that this is the first transfer of the  
packet. On clock edge 19, PHY port 'P' deasserts RSOX as it leaves RVAL asserted and continues to place  
additional bytes of the packet on RDATA. While this example shows a different PHY port ('P') being selected for  
the next packet transfer, the timing is identical if the same PHY port ('N') is chosen for the next packet transfer.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-19 POS-PHY Level 2 Receive Multiple Packet Transfer (polled status mode)  
RCLK  
RADR  
RPXA  
REN  
1F  
M
N
1F  
N
N
1F  
N
O
1F  
O
P
1F  
P
1F  
L
M
1F  
M
O
1F  
O
P
1F  
P
L
1F  
L
M
RVAL  
RDAT  
RSOX  
REOP  
RERR  
P1  
P2  
P3  
P4  
P61 P62 P63 P64  
X
X
P1  
P2  
P3  
Transfer  
From PHY  
N
P
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
7.3.4 POS-PHY Level 3 Functional Timing  
Figure 7-20 shows a multiport transmit interface multiple packet transfer to different PHY ports. On clock edge 1,  
PHY port 'N' indicates to the POS device that it can accept a block of packet data by asserting TPXA. On clock  
edge 3, the POS device selects PHY port 'N' by placing its address on TDATA and asserting TSX while TEN is  
deasserted. On clock edge 4, the POS device starts a packet transfer to PHY port 'N' by deasserting TSX,  
asserting TEN, placing the first byte of packet data on TDATA, and asserting TSOX to indicate the transfer of the  
first byte of the packet. On clock edge 5, the POS device deasserts TSOX as it continues to place additional bytes  
of the packet on TDATA and PHY port 'N' asserts TSPA. On clock edge 11, the POS device polls PHY port 'L'. On  
clock edge 12, PHY port 'N' indicates that it cannot accept any more data transfers by deasserting TSPA. On clock  
edge 13, PHY port 'L' indicates to the POS device that it can accept a block of packet data by asserting TPXA. On  
clock edge 14, the POS device deasserts TEN to end the packet transfer process to PHY port 'N' and selects PHY  
port 'L' by placing its address on TDATA and asserting TSX while TEN is deasserted. On clock edge 15, the POS  
device starts a packet transfer to PHY port 'L' by asserting TEN, deasserting TSX, placing the first byte of packet  
data on TDATA, and asserting TSOX to indicate the transfer of the first byte of the packet. On clock edge 16, the  
POS device deasserts TSOX as it continues to place additional bytes of the packet on TDATA and PHY port 'L'  
asserts TSPA.  
Figure 7-20 POS-PHY Level 3 Transmit Multiple Packet Transfer In-Band Addressing  
TCLK  
TADR  
TPXA  
TSPA  
TEN  
P
L
M
P
N
L
O
M
P
N
L
O
P
L
M
P
N
L
O
P
L
M
P
N
L
O
P
N
O
M
M
N
O
M
N
O
M
N
TSX  
X
X
N
P1  
P2  
P38 P39 P40 P41 P42 P43 P44  
L
P1  
P2  
P3  
P4  
P5  
P6  
TDAT  
TSOX  
TEOP  
TERR  
Transfer  
To PHY  
N
L
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
Figure 7-21 shows a multiport receive-interface multiple packet transfer from different ports. On clock edge 1, the  
POS device indicates to PHY port 'N' that it is ready to accept a block of packet data by asserting REN. On clock  
edge 3, the PHY device selects port 'N' for transfer by asserting RSX and placing its address on RDATA. On clock  
edge 4, PHY port 'N' starts packet transfer by deasserting RSX, asserting RVAL, placing the first byte of the packet  
on RDATA, and asserting RSOX to indicate that this is the first transfer of the packet. On clock edge 5, PHY port  
'N' deasserts RSOX as it leaves RVAL asserted and continues to place additional bytes of the packet on RDATA.  
On clock edge 10, PHY port 'N' places the last byte of the packet on RDATA, and asserts REOP to indicate that  
this is the last transfer of the packet. On clock edge 11, the PHY device deasserts RVAL and REOP ending the  
packet transfer process from port 'N' and selects PHY port 'L' for transfer by asserting RSX and placing its address  
on RDATA. On clock edge 12, PHY port 'L' starts packet transfer by deasserting RSX, asserting RVAL, placing the  
first byte of the packet on RDATA, and asserting RSOX to indicate that this is the first transfer of the packet. On  
clock edge 13, PHY port 'L' deasserts RSOX as it leaves RVAL asserted and continues to place additional bytes of  
the packet on RDATA.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 7-21 POS-PHY Level 3 Receive Multiple Packet Transfer In-Band Addressing  
RCLK  
REN  
RVAL  
RSX  
X
N
P1  
P2  
P3  
P62 P63 P64  
L
P1  
P2  
P3  
P4  
P5  
P6  
P7  
P8  
P9  
RDAT  
RSOX  
REOP  
RERR  
Transfer  
From PHY  
N
L
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
8 FUNCTIONAL DESCRIPTION  
8.1 Cell / Packet Interface Description  
The CELL / PACKET INTERFACE demaps the ATM cells or HDLC packets from a physical data stream in the  
receive direction and maps ATM cells or HDLC packets into a physical data stream in the transmit direction. In cell  
mode, the system interface is connected to an ATM Layer device and cells are transported via a UTOPIA 2,  
UTOPIA 3, POS-PHY 2, or a POS-PHY 3 Bus. In packet mode, the system interface is connected to a Link Layer  
device and the packets are transported via a POS-PHY 2 or a POS-PHY 3 Bus.  
The receive direction extracts the payload from physical data stream, performs cell/packet processing on the  
individual lines, stores the cell/packet data from each line in the FIFO, removes cell/packet data for each port from  
the FIFO, and outputs the cell/packet data to the ATM/Link Layer device via the system interface.  
The transmit direction inputs the cell/packet data from the ATM/Link Layer device via the system interface, stores  
the cell/packet data for each port in the FIFO, removes the cell/packet data for each line from the FIFO, performs  
cell/packet processing for each individual lines, multiplexes the individual lines into the payload, and inserts the  
payload into the physical data stream.  
The Receive Channel Mark and Transmit Channel Mark registers in the receive and transmit framer section are  
used to map channels (DS0s) to the cell/packet interface.  
8.1.1 Reset Descriptions  
Unless noted otherwise, during a reset (RESET pin low) all inputs will be ignored, and all outputs will be low. Unless  
noted otherwise, during a data path reset (LDRST bit = 0), with the exception of the register interface signals, all  
inputs will be ignored, and all should be low. During a data path reset, the register interface signals will operate  
normally allowing the registers to be written and read.  
8.1.2 BIT / BYTE Ordering  
The bits in a byte are received MSB first, LSB last. When they are output serially, they are output MSB first, LSB  
last. The bits in a byte in an incoming signal are numbered in the order they are received, 1 (MSB) to 8 (LSB).  
However, when a byte is stored in memory, the MSB is stored in the highest numbered bit (7), and the LSB is  
stored in the lowest numbered bit (0). This is to differentiate between a byte in memory and the corresponding byte  
in a signal.  
8.2 UTOPIA/POS-PHY/SPI-3 System Interface  
8.2.1 General Description  
The UTOPIA/POS-PHY system interface transports ATM cells or HDLC packets between the DS26556 and an  
ATM or Link Layer device. In UTOPIA mode, the DS26556 is connected to an ATM layer device and cells are  
transported via a UTOPIA L2 or UTOPIA L3 Bus. In POS-PHY packet mode, the DS26556 is connected to a Link  
Layer device and the packets are transported via a POS-PHY 2 or a POS-PHY 3 (or SPI-3) Bus. In POS-PHY cell  
mode, the DS26556 is connected to an ATM layer device and cells are transported via a POS-PHY 2 or a POS-  
PHY 3 (or SPI-3) Bus. The system interface supports 8-bit or 16-bit transfers at a rate of 52 MHz or less.  
The receive direction removes cell/packet data for each port from the FIFO, and outputs the cell/packet data to the  
ATM/Link Layer device via the system interface.  
The transmit direction inputs the cell/packet data from the ATM/Link Layer device via the system interface, and  
stores the cell/packet data for each port in the FIFO.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
8.2.2 Features  
Programmable system interface type – When performing cell mapping/demapping, the system interface can  
be programmed as a UTOPIA Level 2 Bus, a UTOPIA Level 3 Bus, a POS-PHY Level 2 Bus, or a POS-PHY  
Level 3 (or SPI-3) Bus. When performing packet mapping/demapping, the system interface can be  
programmed as a POS-PHY Level 2 Bus or a POS-PHY Level 3 (or SPI-3) Bus.  
Selectable system interface bus width – The data bus can be a 16-bit or 8-bit bus at operations speeds up  
to 52 MHz.  
Supports multiple ports on the system interface – Each T1 or E1 line has its own port address for access  
via the system interface.  
Supports per-port system loopback – Each port can be placed in system loopback which causes  
cells/packets from the transmit FIFO to be looped back to the receive FIFO.  
System interface byte reordering – In 16-bit modes, the received/transmitted order of the bytes transferred  
across the system interface is programmable. i.e., the first byte received/transmitted by ATM cell / packet  
processing can be transferred in [15:8] or [7:0].  
8.2.6 System Interface Bus Controller  
The Transmit and Receive System Interface Bus Controller can be programmed to operate as a UTOPIA Level 2,  
UTOPIA Level 3, POS-PHY Level 2, or POS-PHY Level 3 (or SPI-3) bus controller. It controls the system interface  
bus timing and provides a common interface to the Transmit and Receive FIFO for FIFO status polling and  
cell/packet data transfer. Normally, the first byte transmitted is transferred across the system interface as the most  
significant byte (TDATA[15:8] in 16-bit mode). If byte reordering is enabled, the first byte transmitted is transferred  
across the system interface as the least significant byte (TDATA[7:0]).On the receive side, the first byte received is  
transferred across the system interface as the most significant byte (RDATA[15:8] in 16-bit mode). If byte  
reordering is enabled, the first byte received is transferred across the system interface as the least significant byte  
(RDATA[7:0]).  
See Figure 8-1 and Figure 8-2. Byte reordering is ignored in 8-bit mode.  
Figure 8-1 Normal Packet Format in 16-Bit Mode  
Bit 15  
Byte 1  
Bit 0  
Byte 2  
1st Transfer  
2nd Transfer  
Byte 3  
Byte 4  
Byte 2n-3  
Byte 2n-2  
(n-1)th Transfer  
nth Transfer  
Byte 2n-1  
Byte 2n  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 8-2 Byte Reordered Packet Format in 16-Bit Mode  
Bit 15  
Byte 2  
Bit 0  
Byte 1  
1st Transfer  
2nd Transfer  
Byte 4  
Byte 3  
Byte 2n-2  
Byte 2n-3  
(n-1)th Transfer  
nth Transfer  
Byte 2n  
Byte 2n-1  
8.2.6.4 UTOPIA Level 2, Transmit Side  
In UTOPIA Level 2, an ATM layer device pushes cells across the system interface. The ATM layer device polls the  
individual ports of the DS26556 to determine which ports have space available for a cell, and selects a port for cell  
transfer. More than one PHY layer device can be present on a UTOPIA Level 2 bus. Whether or not the HEC byte  
is transferred with the cells is programmable.  
The Transmit System Interface Bus Controller accepts a transmit clock (TSCLK), transmit address (TADR[4:0]),  
transmit enable (TEN), and a transmit data bus consisting of transmit data (TDATA[15:0]), transmit parity (TPRTY),  
and transmit start of cell (TSOX). It outputs transmit direct cell available (TDXA) and transmit polled cell available  
(TPXA) signals. The transmit data bus is used to transfer cell data whenever one of the ports is selected for cell  
data transfer. TSOX is asserted during the first transfer of a cell, cell data is transferred on TDATA, and the data  
bus parity is indicated on TPRTY. All signals are sampled or updated using TSCLK. The TDXA and TPXA signals  
are used to indicate when the Transmit FIFO has space available for a programmable number of cells. There is a  
TDXA for each port in the device. TDXA goes high when the associated port's Transmit FIFO has more space  
available than a programmable number of cells. TDXA goes low when the associated port's Transmit FIFO is full  
(does not have space for another cell). TPXA reflects the current status of a port's TDXA signal when the port is  
polled. The TPXA signal is tri-stated unless one of the ports is being polled for FIFO fill status.  
8.2.6.5 UTOPIA Level 3, Transmit Side  
In UTOPIA Level 3, the ATM layer device pushes cells across the system interface. The ATM layer device polls the  
individual ports of the DS26556 to determine which ports have space available for a cell, and selects a port for cell  
transfer. Only one PHY layer device can be present on a UTOPIA Level 3 bus. Whether or not the HEC byte is  
transferred with the cells is programmable.  
The Transmit System Interface Bus Controller accepts a transmit clock (TSCLK), transmit address (TADR[7:0]),  
transmit enable (TEN), and a transmit data bus consisting of transmit data (TDATA[15:0]), transmit parity (TPRTY),  
and transmit start of cell (TSOX). It outputs transmit direct cell available (TDXA) and transmit polled cell available  
(TPXA) signals. The transmit data bus is used to transfer cell data whenever one of the ports is selected for cell  
data transfer. TSOX is asserted during the first transfer of a cell, cell data is transferred on TDATA, and the data  
bus parity is indicated on TPRTY. All signals are sampled or updated using TSCLK. The TDXA and TPXA signals  
are used to indicate when the Transmit FIFO has space available for a programmable number of cells.  
There is a TDXA for each port in the device. TDXA goes high when the associated port's Transmit FIFO has more  
space available than a programmable number of cells. TDXA goes low when the associated port's Transmit FIFO  
is full (does not have space for another cell). TPXA reflects the current status of a port's TDXA signal when the port  
is polled. The TPXA signal is always driven.  
8.2.6.6 UTOPIA Level 2, Receive Side  
In UTOPIA Level 2, the ATM layer device pulls cells across the system interface. The ATM layer device polls the  
individual ports to determine which ports have cells available, and selects a port for cell transfer. More than one  
PHY layer device can be present on a UTOPIA Level 2 bus. Whether or not the HEC byte is transferred with the  
cells is programmable.  
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The Receive System Interface Bus Controller accepts a receive clock (RSCLK), receive address (RADR[4:0]), and  
receive enable (REN). It outputs a receive data bus consisting of receive data (RDATA[15:0]), receive parity  
(RPRTY), and receive start of cell (RSOX), as well as, receive direct cell available (RDXA) and receive polled cell  
available (RPXA) signals. The receive bus is used to transfer cell data whenever one of the ports is selected for  
cell data transfer. RSOX is asserted during the first transfer of a cell, cell data is transferred on RDATA, and the  
data bus parity is indicated on RPRTY. All signals are sampled or updated using RSCLK. The data bus is tri-stated  
unless REN is asserted (low) and one of the ports is selected for data transfer. The RDXA and RPXA signals are  
used to indicate when the Receive FIFO has a programmable number of cells available for transfer. There is an  
RDXA for each port in the device. RDXA goes high when the associated port's Receive FIFO contains more than a  
programmable number of cells. RDXA goes low when the associated port's Receive FIFO is empty (does not  
contain any cells). RPXA reflects the current status of a port's RDXA signal when the port is polled. The RPXA  
signal is tri-stated unless one of the ports is being polled for FIFO fill status.  
8.2.6.2 UTOPIA Level 3, Receive Side  
In UTOPIA Level 3, the ATM layer device pulls cells across the system interface. The ATM layer device polls the  
individual ports to determine which ports have cells available, and selects a port for cell transfer. Only one PHY  
layer device can be present on a UTOPIA Level 3 bus. Whether or not the HEC byte is transferred with the cells is  
programmable.  
The Receive System Interface Bus Controller accepts a receive clock (RSCLK), receive address (RADR[7:0]), and  
receive enable (REN). It outputs a receive data bus consisting of receive data (RDATA[15:0]), receive parity  
(RPRTY), and receive start of cell (RSOX), as well as, receive direct cell available (RDXA) and receive polled cell  
available (RPXA) signals. The receive data bus is used to transfer cell data whenever one of the ports is selected  
for cell data transfer. RSOX is asserted during the first transfer of a cell, cell data is transferred on RDATA, and the  
data bus parity is indicated on RPRTY. All signals are sampled or updated using RSCLK. The data bus is always  
driven. The RDXA and RPXA signals are used to indicate when the Receive FIFO has a programmable number of  
cells available for transfer. There is an RDXA for each port in the device. RDXA goes high when the associated  
port's Receive FIFO contains more than a programmable number of cells. RDXA goes low when the associated  
port's Receive FIFO is empty (does not contain any cell ends). RPXA reflects the current status of a port's RDXA  
signal when the port is polled. The RPXA signal is always driven.  
8.2.6.3 POS-PHY Level 2, Transmit Side  
In POS-PHY Level 2, the Link layer device pushes packets across the system interface. The Link layer device polls  
the individual ports of the DS26556 to determine which ports have space available for packet data, and selects a  
port for packet data transfer. More than one PHY layer device can be present on a POS-PHY Level 2 bus.  
The Transmit System Interface Bus Controller accepts a transmit clock (TSCLK), transmit address (TADR[4:0]),  
transmit enable (TEN), and a transmit data bus consisting of transmit data (TDATA[15:0]), transmit parity (TPRTY),  
transmit start of packet (TSOX), transmit end of packet (TEOP), transmit error (TERR), and transmit modulus  
(TMOD). It outputs transmit direct packet available (TDXA), transmit polled packet available (TPXA), and transmit  
selected packet available (TSPA) signals. The transmit data bus is used to transfer packet data whenever one of  
the ports is selected for packet data transfer. TSOX is asserted during the first transfer of a packet, TEOP is  
asserted during the last transfer of a packet, TERR is asserted when a packet has an error, TMOD indicates the  
number of bytes transferred on TDATA during the last transfer of a packet, packet data is transferred on TDATA,  
and the data bus parity is indicated on TPRTY. All signals are sampled and updated using TSCLK. The TDXA,  
TPXA, and TSPA signals are used to indicate when the Transmit FIFO has space available for a programmable  
number of bytes. There is a TDXA for each port in the device. TDXA goes high when the associated port's  
Transmit FIFO has space available for more than a programmable number of bytes. TDXA goes low when the  
associated port's Transmit FIFO is full. TPXA reflects the current status of a port's TDXA signal when the system  
interface is in polled mode. TSPA reflects the current status of a port's TDXA signal when the port is selected. The  
TSPA signal is tri-stated unless TEN is asserted (low) and one of the ports is selected for packet data transfer. The  
TPXA signal is tri-stated unless one of the ports is being polled for FIFO fill status.  
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8.2.6.4 POS-PHY Level 3 (or SPI-3), Transmit Side  
In POS-PHY Level 3 (or SPI-3), the Link layer device pushes packets across the system interface. The Link layer  
device polls the individual ports of the DS26556 to determine which ports have space available for packet data,  
and selects a port for packet data transfer. Only one PHY layer device can be present on a POS-PHY Level 3 (or  
SPI-3) bus.  
The Transmit System Interface Bus Controller accepts a transmit clock (TSCLK), transmit enable (TEN), and a  
transmit data bus consisting of transmit data (TDATA[15:0]), transmit parity (TPRTY), transmit start of packet  
(TSOX), transmit end of packet (TEOP), transmit error (TERR), transmit start of transfer (TSX), and transmit  
modulus (TMOD). It outputs transmit direct packet available (TDXA), transmit polled packet available (TPXA), and  
transmit selected packet available (TSPA) signals. The transmit bus is used to transfer packet data whenever one  
of the ports is selected for packet data transfer. TSOX is asserted during the first transfer of a packet, TEOP is  
asserted during the last transfer of a packet, TERR is asserted when a packet has an error, TMOD indicates the  
number of bytes transferred on TDATA during the last transfer of a packet, TSX is asserted when the selected  
FIFO's port address has been placed on TDATA, packet data is transferred on TDATA, and the data bus parity is  
indicated on TPRTY. All signals are sampled and updated using TSCLK. The TDXA, TPXA, and TSPA signals are  
used to indicate when the Transmit FIFO has space available for a programmable number of bytes. There is a  
TDXA for each port in the device. TDXA goes high when the associated port's Transmit FIFO has space available  
for more than a programmable number of bytes. TDXA goes low when the associated port's Transmit FIFO is full.  
TPXA reflects the current status of a port's TDXA signal when the port is polled. TSPA reflects the current status of  
a port's TDXA signal when the port is selected. The TPXA and TSPA signals are always driven.  
8.2.6.5 POS-PHY Level 2, Receive Side  
In POS-PHY Level 2, the Link layer device pulls packets across the system interface. The Link layer device polls  
the individual ports to determine which ports have packet data available, and selects a port for packet data  
transfer. More than one PHY layer device can be present on a POS-PHY Level 2 bus.  
The Receive System Interface Bus Controller accepts a receive clock (RSCLK), receive address (RADR[4:0]), and  
receive enable (REN). It outputs a receive data bus consisting of receive data (RDATA[15:0]), receive parity  
(RPRTY), receive start of packet (RSOX), receive end of packet (REOP), receive error (RERR), receive data valid  
(RVAL), and receive modulus (RMOD), as well as, a receive direct packet available (RDXA) signal and a receive  
polled packet available (RPXA) signal. The receive data bus is used to transfer packet data whenever one of the  
ports is selected for packet data transfer. RSOX is asserted during the first transfer of a packet, REOP is asserted  
during the last transfer of a packet, RERR is asserted when a packet has an error, RMOD indicates the number of  
bytes transferred on RDATA during the last transfer of a packet, RVAL is asserted when the receive data bus is  
valid, RDATA transfers packet data, and RPRTY indicates the data bus parity. All signals are sampled and  
updated using RSCLK. The RDXA and RPXA signals are used to indicate when the Receive FIFO has a  
programmable number of bytes or an end of packet available for transfer. There is an RDXA for each port in the  
device. RDXA goes high when the associated port's Receive FIFO contains more than a programmable number of  
bytes or an end of packet. RDXA goes low when the associated port's Receive FIFO is empty. RPXA reflects the  
current status of a port's RDXA signal when the port is polled. The data bus is tri-stated unless REN is asserted  
(low) and one of the ports is selected for packet data transfer. The RPXA signal is tri-stated unless one of the ports  
is being polled for FIFO fill status.  
8.2.6.6 POS-PHY Level 3 (or SPI-3), Receive Side  
In POS-PHY Level 3, the DS26556 pushes packets across the system interface. The DS26556 selects a port for  
packet data transfer when it has packet data available. Only one PHY layer device can be present on a POS-PHY  
Level 3 (or SPI-3) bus.  
The Receive System Interface Bus Controller accepts a receive clock (RSCLK) and receive enable (REN). It  
outputs a receive data bus consisting of receive data (RDATA[15:0]), receive parity (RPRTY), receive start of  
packet (RSOX), receive end of packet (REOP), receive error (RERR), receive data valid (RVAL), receive start of  
transfer (RSX), and receive modulus (RMOD). The receive data bus is used to transfer packet data whenever one  
of the ports has packet data available for transfer. RSOX is asserted during the first transfer of a packet, REOP is  
asserted during the last transfer of a packet, RERR is asserted when a packet has an error, RMOD indicates the  
number of bytes transferred on RDATA during the last transfer of a packet, RSX is asserted when the Link layer  
port address has been placed on RDATA, RVAL is asserted when the receive data bus is valid, RDATA transfers  
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packet data, and RPRTY indicates the data bus parity. All signals are sampled and updated using RSCLK. The  
data bus is always driven.  
In POS-PHY Level 3 (or SPI-3) the Receive System Interface Bus Controller determines which port to transfer data  
from using a round-robin arbitration scheme (the ports are checked one after another in numerical order according  
to their line number x. A transfer is initiated from a port when it is not almost empty (contains more data than the  
almost empty level or contains an end of packet). Transfer from a port is terminated when the maximum burst  
length has been transferred, the FIFO is emptied, or an end of packet is transferred while the Receive FIFO is  
almost empty (contains the same or less data than the almost empty level and does not contain an end of packet).  
When a transfer is terminated, a transfer is initiated from the next available port that is not almost empty. At the end  
of a packet or between a transfer from one port and the transfer from the next port, RVAL will go low for a  
programmable number of clock cycles (0-7) to allow the POS-PHY master to halt data transfer. At the end of a  
packet, data transfer will continue from the same port if the port is not almost empty. When the maximum burst  
length has been transferred, data transfer will continue from the same port if no other port has data available, and  
the port is not almost empty. The maximum burst length is programmable (8 – 256 bytes in four byte increments),  
or can be disabled.  
8.3 ATM Cell / HDLC Packet Processing  
8.3.1 General Description  
The ATM cell / packet processing demaps the ATM cells or HDLC packets from the receive data stream and maps  
ATM cells or HDLC packets into the transmit data stream. ATM cell / packet processing supports any framed or  
unframed bit synchronous or byte synchronous (octet aligned) data stream.  
The receive direction extracts the payload from physical data stream, performs cell/packet processing on the  
individual lines, and stores the cell/packet data from each line in the FIFO.  
The transmit direction removes the cell/packet data for each line from the FIFO, performs cell/packet processing  
for each individual line and inserts the payload into the physical data stream.  
8.3.2 Features  
8.3.2.1 General  
Supports bit or byte wide, framed or unframed data lines – Each port is programmable as bit synchronous  
or octet aligned, the data stream can be framed or unframed, and the clock can be continuous or gapped.  
Bit reordering – The received/transmitted order of the bits as transferred across the system interface is  
programmable on a per-port basis. That is, in bit synchronous mode, the first bit received/transmitted by ATM  
cell/packet processing can be transferred in bit position 7 (15 or 7) or bit position 0 (8 or 0). In octet aligned  
mode, the bit received/transmitted by ATM cell/packet processing in bit position 7 can be transferred in bit  
position 7 (15 or 7) or bit position 0 (8 or 0).  
8.3.2.2 ATM Cell Processor  
Programmable HEC insertion and extraction – The transmit side can be programmed to accept cells from  
the system interface that do or do not contain a HEC byte. If cells are transferred without a HEC byte, the HEC  
byte will be computed and inserted. If cells are transferred with a HEC byte, then the transferred HEC byte can  
be programmed to be passed through or overwritten with a newly calculated HEC. The receive side can be  
programmed to send cells to the system interface that do or don't contain the HEC byte.  
Programmable erred cell insertion – An HEC error mask can be programmed for insertion of single or  
multiple errors individually or continuously at a programmable rate.  
Programmable transmit cell synchronization – The transmit data line can be provisioned to be bit  
synchronous or octet aligned.  
Programmable header cell pass-through – Receive cell filtering can pass-through only those cells that  
matching a programmable header value.  
Selectable idle/unassigned/invalid/programmable header cell padding and filtering – Transmit cell  
padding can be programmed for idle cell or programmable header cell padding. The padded cell payload byte  
contents are also programmable. Receive cell filtering can be programmed for any combination of idle cell,  
unassigned cell, invalid cell, or programmable header cell filtering. Or, all cell filtering can be disabled.  
Optional header error correction – Receive side single bit header error correction can enabled.  
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Separate corrected and uncorrected erred cell counts – Separate counts of erred cells containing a  
corrected HEC error, and cells containing non-corrected HEC errors are kept.  
Optional HEC uncorrected erred cell filtering – Uncorrected erred cell extraction can be disabled.  
Selectable cell scrambling/descrambling – Cell scrambling and/or descrambling can be disabled. The  
scrambling can be a self-synchronous scrambler (x43 + 1) over the payload only, a self-synchronous scrambler  
over the entire cell, or a Distributed Sample Scrambler (x31 + x28 + 1).  
Optional HEC calculation coset polynomial addition – The performance of coset polynomial addition during  
HEC calculation can be disabled.  
8.3.2.3 HDLC Packet Processor  
Programmable FCS insertion and extraction – The transmit side can be programmed to accept packets  
from the system interface that do or don't contain FCS bytes. If packets are transferred without FCS bytes, the  
FCS will be computed and appended to the packet. If packets are transferred with FCS bytes, then the FCS  
can be programmed to be passed through or overwritten with a newly calculated FCS. The receive side can be  
programmed to send packets to the system interface that do or don't contain FCS bytes.  
Programmable transmit packet synchronization – The transmit data line can be provisioned to be bit  
synchronous or octet aligned.  
Programmable FCS type – The FCS can be programmed to be a 16-bit FCS or a 32-bit FCS.  
Supports FCS error insertion – FCS error insertion can be programmed for insertion of errors individually or  
continuously at a programmable rate.  
Supports bit or byte stuffing/destuffing – The bit or byte synchronous (octet aligned) mode determines the  
bit or byte stuffing/destuffing.  
Programmable packet size limits – The receive side can be programmed to abort packets over a  
programmable maximum size or under a programmable minimum size. The maximum packet size allowed is  
65,535 bytes.  
Selectable packet scrambling/descrambling – Packet scrambling and/or descrambling can be disabled.  
Separate FCS erred packet and aborted packet counts – Separate counts of aborted packets, size violation  
packets, and FCS erred packets are kept.  
Optional erred packet filtering – Erred packet extraction can be disabled  
Programmable inter-frame fill – The transmit inter-frame fill value is programmable.  
8.3.3 Transmit Cell/Packet Processor  
The Transmit Cell Processor and Transmit Packet Processor both receive the 32-bit parallel data stream from the  
Transmit FIFO, however, only one of the processors will be enabled. Which processor is enabled is determined by  
the system interface mode. In UTOPIA mode, the Transmit Cell Processor is enabled. In POS-PHY mode, if the  
CPC1.PMCPE bit is low, the Transmit Packet Processor is enabled. If the CPC1.PMCPE bit (is high, the Transmit  
Cell Processor is enabled.  
8.3.4 Receive Cell/Packet Processor  
The Receive Cell Processor and Receive Packet Processor both receive the incoming data stream from the  
Receive Framer (minus all overhead and stuff data), however, only one of the processors will be enabled. The  
other will be disabled. Which processor is enabled is determined by the system interface mode. In UTOPIA mode,  
the Receive Cell Processor is enabled. In POS-PHY mode, if the CPC1.PMCPE bit is low, the Receive Packet  
Processor is enabled. If the CPC1.PMCPE bit is high, the Receive Cell Processor is enabled.  
The bits in a byte are received MSB first, LSB last. When they are output serially, they are output MSB first, LSB  
last. The bits in a byte in an incoming signal are numbered in the order they are received , 1 (MSB) to 8 (LSB).  
However, when a byte is stored in a register, the MSB is stored in the highest numbered bit (7], and the LSB is  
stored in the lowest numbered bit (0). This is to differentiate between a byte in a register and the corresponding  
byte in a signal.  
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8.3.5 Cell Processor  
8.3.5.1 Transmit Cell Processor  
The Transmit Cell Processor accepts data from the Transmit FIFO and performs bit reordering, cell padding, HEC  
processing, cell error insertion, and cell scrambling. The data output from the Transmit Cell Processor can be  
either a serial data stream (bit synchronous mode) or an 8-bit parallel data stream (octet-aligned mode). Cell  
processing can be disabled. Disabling cell processing disables cell padding, HEC processing, and cell error  
insertion. Only bit reordering and cell scrambling are not disabled.  
When cell processing is disabled, data is continually read out of the Transmit FIFO. When the Transmit FIFO is  
empty, the output data stream is padded with FFh until the Transmit FIFO contains more data than the "almost  
empty" level.  
The 32-bit data words read from the Transmit FIFO are multiplexed into an 8-bit parallel data stream and passed  
on to bit reordering.  
Bit reordering changes the bit order of each byte. If bit reordering is enabled, the incoming 8-bit data stream  
DT[7:0] with DT[7] being the MSB and DT[0] being the LSB is rearranged so that the MSB is in DT[0] and the LSB  
is in DT[7] of the outgoing data stream DT[7:0]. In bit synchronous mode, DT[7] is the first bit transmitted. If cell  
processing is disabled the data stream is passed on to cell scrambling, bypassing cell padding, HEC processing,  
and cell error insertion.  
Cell padding inserts fill cells. After a cell end, fill cells are inserted into the data stream if the Transmit FIFO does  
not contain a complete cell. The fill cell type and fill cell payload value are programmable. The resulting data  
stream is passed on to HEC processing. If cell processing is disabled, cell padding will not be performed.  
HEC processing calculates a HEC and inserts it into the cell. HEC calculation is a CRC-8 calculation over the four  
header bytes. The polynomial used is x8 + x2 + x + 1. The coset polynomial, x6 + x4 + x2 + 1, is added (modulo 2) to  
the residue. The calculated HEC is then inserted into the byte immediately following the header. HEC coset  
polynomial addition is programmable. If the cell received from the Transmit FIFO contains a HEC byte, the  
received HEC byte can be passed through or overwritten with the calculated HEC byte. HEC byte pass through is  
programmable. If the cell received from the Transmit FIFO does not contain a HEC byte, the calculated HEC byte  
is inserted into the cell. If cell processing is disabled, HEC processing will not be performed.  
Cell error insertion inserts errors into the HEC byte. The HEC bits to be errored are programmable. Error insertion  
can be controlled by a register or by the manual error insertion input (TMEI). The error insertion initiation type  
(register or input) is programmable. If a register controls error insertion, the number and frequency of the errors are  
programmable. If cell processing is disabled, cell error insertion will not be performed.  
Cell scrambling can scramble the 48-byte cell payload, scramble the entire cell data stream, or scramble the data  
stream with a Distributed Sample Scrambler (DSS). If the payload or the entire data stream is scrambled, a self-  
synchronous scrambler with a generation polynomial of x43 + 1 is used. For payload scrambling, the scrambler  
scrambles the 48-byte payload, and does not scramble the four header or the HEC bytes. For a DSS scrambled  
data stream, a distributed sample scrambler with a generation polynomial of x31 + x28 + 1 is used for scrambling.  
The transmit DSS scrambler scrambles the 48-byte payload and the four byte header. It scrambles the first HEC  
bit (HEC[1]) with the first transmit DSS scrambler sample (the transmit DSS scrambler bit from 211 bits earlier),  
scrambles the second HEC bit (HEC[2]) with the second transmit DSS scrambler sample (the current transmit DSS  
scrambler bit), and does not scramble the remaining HEC bits (HEC[3:8]). DSS scrambling can only be performed  
in bit synchronous mode. Cell scrambling is programmable (payload, entire data stream, or DSS). If cell processing  
is disabled, the entire data stream will be scrambled whenever scrambling is enabled  
Once all cell processing has been completed, in bit synchronous mode, the 8-bit parallel data stream is multiplexed  
into a serial data stream and passed on. In octet aligned mode, the 8-bit parallel data stream is passed on.  
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8.3.5.2 Receive Cell Processor  
The Receive Cell Processor performs cell descrambling, cell delineation, cell filtering, header pattern comparison,  
OCD detection, HEC error monitoring, HEC byte filtering, and bit reordering. The data coming in can be either a  
serial data stream (bit synchronous mode) or an 8-bit parallel data stream (octet aligned mode). The type of data  
stream received affects cell descrambling and cell delineation, however, it does not affect OCD detection, HEC  
error monitoring, cell filtering, header pattern comparison, HEC byte filtering, or bit reordering. Cell processing can  
be disabled (clear-channel enable). Disabling cell processing disables cell delineation, OCD detection, cell filtering,  
header pattern comparison, HEC error monitoring, and HEC byte filtering. Only cell descrambling and bit  
reordering are not disabled.  
Cell descrambling can descramble the 48-byte cell payload, descramble the entire cell data stream, or descramble  
a data stream scrambled by a Distributed Sample Scrambler (DSS). If the payload or the entire data stream is  
descrambled, a self-synchronous scrambler with a generation polynomial of x43 + 1 is used for descrambling.  
Payload descrambling descrambles the 48-byte payload, and does not descramble the four header bytes or the  
HEC byte. For a DSS scrambled data stream, a distributed sample scrambler with a generation polynomial of x31  
+
x28 + 1 is used for descrambling. The receive DSS scrambler is synchronized to the transmit DSS scrambler by  
DSS scrambler synchronization. DSS descrambling can only be performed in bit synchronous mode. Cell  
descrambling is programmable (payload, entire data stream, or DSS). In bit synchronous mode, descrambling is  
performed one bit at a time, and the serial data stream is demultiplexed in to an 8-bit data stream before being  
passed on. In octet aligned mode, descrambling is performed 8-bits at a time, and only payload or entire data  
stream descrambling can be performed. When cell processing is disabled, the entire data stream will be  
descrambled if descrambling is enabled.  
DSS Scrambler Synchronization synchronizes the receive DSS scrambler with the transmit DSS scrambler used to  
scramble the incoming data stream. The DSS Scrambler Synchronization state machine has three states:  
"Acquisition", "Verification", and "Steady State". The "Acquisition" state adds the transmit DSS scrambler samples  
from 16 incoming cells into the receive DSS scrambler (32 samples total). The samples are derived from the two  
MSBs (HEC[1:2]) of the incoming HEC byte. Each time the samples in a cell are loaded into the receive DSS  
scrambler, the confidence counter is incremented. When the confidence counter reaches 16, DSS scrambler  
synchronization transitions to the “Verification” state. The "Verification" state verifies the samples in the incoming  
cells by comparing the samples from the cell with the corresponding receive DSS scrambler bits. Each time both  
samples from a cell match the corresponding receive DSS scrambler bits, the confidence counter is incremented.  
Each time one of the samples from a cell does not match the corresponding receive DSS scrambler bit, the  
confidence counter is decremented if the confidence counter reaches 24, DSS scrambler synchronization  
transitions to the “Steady State” state. If the confidence counter reaches 8, DSS scrambler synchronization  
transitions to the “Acquisition” state. The "Steady State" state continues to verify the samples in the incoming cells.  
Each time both samples from a cell match the corresponding receive DSS scrambler bits, the confidence counter is  
incremented (maximum count = 24). Each time one of the samples from a cell does not match the corresponding  
receive DSS scrambler bit, the confidence counter is decremented. If the confidence counter reaches 16, DSS  
scrambler synchronization transitions to the “Acquisition” state. The DSS scrambler synchronization state diagram  
is shown in Figure 8-3. DSS scrambler synchronization starts in the “Acquisition” state. Note: All ATM cells are  
discarded during the “Acquisition” and “Verification” states.  
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Figure 8-3 Receive DSS Scrambler Synchronization State Diagram  
Steady  
State  
8 Cells Fail Verification  
32 Samples Loaded  
Verification  
Acquisition  
If cell processing is disabled, a cell boundary is arbitrarily chosen, and the data is divided into "cells" whose size is  
programmable. If HEC transfer is enabled in the receive system interface, the incoming data stream will be divided  
into 53-byte "cells". If HEC transfer is disabled in the receive system interface, the data is divided into 52-byte  
"cells". These cells are then passed on to bit reordering bypassing cell delineation, OCD detection, cell filtering,  
header pattern comparison, HEC error monitoring, and HEC byte filtering.  
Cell delineation determines the cell boundary by identifying the header bytes and the HEC byte of a cell, and  
detects an out of cell delineation (OCD) condition or a change of cell delineation (COCD). Cell delineation is  
performed off-line, and the data path cell boundary is only updated by cell delineation if an OCD condition is  
present. Performing cell delineation off-line results in fewer cells being discarded when the cell boundary changes.  
If DSS scrambling is enabled (bit synchronous mode only), only the six least significant bits (LSBs) of the HEC  
(HEC[3:8]) are used for cell delineation, as the two most significant bits (MSBs) are scrambled. An OCD condition  
is declared if seven consecutive cells are received with incorrect HEC bytes. An OCD condition is terminated if  
“Delta” consecutive cells are received with correct HEC bytes, if cell delineation updates the data path cell  
boundary. All ATM cells are discarded during an OCD condition. A COCD is declared when Cell Delineation  
updates the data path cell boundary with a cell boundary that is different from the current data path cell boundary .  
Cell delineation has three states: "Hunt", "Presync", and "Sync". The "Hunt" state searches for the cell boundary.  
Each time slot is checked for an HEC byte (six LSBs of the HEC byte if DSS is enabled). The cell boundary is set  
once the header and HEC bytes are identified, and cell delineation transitions to the “Presync” state. The "Presync"  
state verifies the cell boundary identified in the “Hunt” state. The HEC is checked in each incoming cell. If “Delta”  
cells (including the "Hunt" to "Presync" transition cell) with a correct HEC are received, cell delineation transitions  
to the “Sync” state. If a cell with an incorrect HEC is received, cell delineation transitions to the “Hunt” state. The  
"Sync" state checks the HEC in each cell. If a cell with a correct HEC is received, cell delineation updates the data  
path cell boundary if an OCD condition is present. If a cell with an incorrect HEC is received, cell delineation  
transitions to the “Hunt” state. The cell delineation state diagram is shown in Figure 8-4. The cell delineation  
process starts in the "Hunt" state. In octet-aligned mode, the HEC check is performed one byte at a time, so up to  
53 checks may be needed to find the cell boundary. In bit synchronous mode, the HEC check is performed one bit  
at a time, so up to 424 checks may be needed to find the cell boundary. HEC calculation coset polynomial addition  
can be disabled. The cell delineation process can be programmed to ignore the first header byte (for DQDB  
applications) when calculating the HEC. If cell processing is disabled, cell delineation will not be performed. A  
“Delta” of eight is used for unframed modes and a “Delta” of six is used for framed modes. In bit synchronous  
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mode, the serial data stream is demultiplexed into an 8-bit parallel data stream (as determined by the data path cell  
boundary updated) before being passed on to cell filtering.  
Figure 8-4 Cell Delineation State Diagram  
Sync  
Incorrect HEC  
Presync  
Hunt  
Correct HEC  
Cell filtering discards specific cell types. The 8-bit parallel data stream is monitored for idle, unassigned, and invalid  
cells. (Cells discarded during cell delineation or DSS descrambling are not monitored for cell filtering.) If cell  
filtering is enabled and the indicated cell type is found, the cell is discarded. Idle cell, unassigned cell, and invalid  
cell filtering are programmable. Idle cells have a header value of 00000000 00000000 00000000 00000001.  
Unassigned cells have a header value of xxxx0000 00000000 00000000 0000xxx0. Where x can be any value.  
Invalid cells have a header value of xxxxyyyy yyyy0000 00000000 0000xxxx. Where x can be any value and  
yyyyyyyy can be any value other than 00000000. All cells discarded are counted. If cell processing is disabled, cell  
filtering will not be performed.  
Header pattern comparison checks for a specific pattern in the header, and either discards and counts cells with a  
matching header (discard match), discards and counts cells without a matching header (discard no match), counts  
cells with a matching header (count match), or counts cells without a matching header (count no match). (Cells  
discarded during OCD detection, DSS descrambling, or cell filtering processes are not monitored for header  
pattern comparison.) The 8-bit parallel data stream is monitored for cells that have a header that matches the  
comparison header. In discard match mode, cells with a matching header are counted and discarded. In discard no  
match mode, cells without a matching header are counted and discarded. In count match mode, cells with a  
matching header are counted and passed on. In count no match mode, cells without a matching header are  
counted and passed on. The comparison header and comparison header pattern mode are programmable. If cell  
processing is disabled, header pattern comparison will not be performed.  
HEC error monitoring checks the HEC and detects errored and correctable cell headers. (Cells discarded during  
OCD detection, DSS descrambling, cell filtering, or header pattern comparisons are not monitored for HEC errors.).  
HEC Error Monitoring has two states, the "Correction" and "Detection" states. . In the “Correction” state, cells  
received without any header errors (good cells) are passed on. Cells received with a single header error  
(correctable cells) are corrected and passed on. The corrected cell count is incremented. Cells received with  
multiple errors are considered errored cells. If errored cell extraction is enabled, errored cells are discarded, and  
the errored cell count is incremented. If errored cell extraction is disabled, errored cells are passed on. If a cell is  
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received with an incorrect HEC, HEC error monitoring transitions to the “Detection” state. In the “Detection” state,  
good cells are passed on. Cells received with one or more errors are considered errored cells. If m cells are  
received with a correct HEC or the data path cell boundary is updated, HEC error monitoring will transition to the  
“Correction” state. The value of m is programmable (1, 2, 4, or 8). The HEC Error Monitoring state diagram is  
shown in Figure 8-5. HEC Error Monitoring starts in the “Correction” state. If header error correction is disabled,  
HEC error monitoring will remain in the “Detection” state. If cell processing is disabled, HEC error monitoring will  
not be performed.  
Figure 8-5 HEC Error Monitoring State Diagram  
corrected cell  
mth good cell  
Correction  
Detection  
cell boundary update  
errored cell  
HEC byte filtering discards the HEC byte. If HEC transfer is disabled in the receive system interface, the HEC byte  
is extracted from the cell and discarded. The resulting 52-byte cell is then passed on for storage in the Receive  
FIFO. If HEC transfer is enabled, the 53-byte cell is passed on for storage in the Receive FIFO. If cell processing is  
disabled, HEC byte filtering will not be performed.  
Bit reordering changes the bit order of each byte. If bit reordering is enabled, the incoming 8-bit data stream  
DT[7:0] with DT[7] being the MSB and DT[0] being the LSB is rearranged so that the MSB is in DT[0] and the LSB  
is in DT[7] of the outgoing FIFO data stream DT[7:0]. In bit synchronous mode, DT[7] is the first bit received.  
Once all cell processing has been completed, the 8-bit parallel data stream is demultiplexed into a 32-bit parallel  
data stream and passed on to the Receive FIFO. Cells are stored in the Receive FIFO in a cell format. regardless  
of whether or not they are transferred across a UTOPIA or POS-PHY interface.  
Figure 8-6 Cell Format for 53-Byte Cell With 16-Bit Data Bus  
Bit 15  
Header 1  
Bit 0  
Header 2  
1st Transfer  
2nd Transfer  
3rd Transfer  
4th Transfer  
Header 3  
HEC  
Header 4  
00h  
Payload 1  
Payload 2  
Payload 45  
Payload 46  
26th Transfer  
27th Transfer  
Payload 47  
Payload 48  
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Figure 8-7 Cell Format for 52-Byte Cell With 16-Bit Data Bus  
Bit 15  
Header 1  
Bit 0  
Header 2  
1st Transfer  
2nd Transfer  
3rd Transfer  
Header 3  
Header 4  
Payload 1  
Payload 2  
Payload 45  
Payload 46  
25th Transfer  
26th Transfer  
Payload 47  
Payload 48  
8.3.6 Packet Processor  
8.3.6.1 Transmit Packet Processor  
The Transmit Packet Processor accepts data from the Transmit FIFO performs bit reordering, FCS processing,  
packet error insertion, stuffing, packet abort sequence insertion, inter-frame padding, and packet scrambling. The  
data output from the Transmit Packet Processor can be either a serial data stream (bit synchronous mode) or an 8-  
bit parallel data stream (octet-aligned mode). The type of data stream output from the Transmit Packet Processor  
affects stuffing, abort insertion, inter-octet padding, inter-frame padding, and packet scrambling, however, it does  
not affect bit reordering, FCS processing, or packet error insertion. Packet processing can be disabled. Disabling  
packet processing disables FCS processing, packet error insertion, stuffing, packet abort sequence insertion, and  
inter-frame padding. Only bit reordering and packet scrambling are not disabled.  
When packet processing is disabled, data is continually read out of the Transmit FIFO. When the Transmit FIFO is  
read empty, the output data stream will be padded with FFh until the Transmit FIFO contains more data than the  
"almost empty" level. The 32-bit data words read from the Transmit FIFO are multiplexed into an 8-bit parallel data  
stream and passed on to bit reordering.  
Bit reordering changes the bit order of each byte. If bit reordering is enabled, the incoming 8-bit data stream  
DT[7:0] with DT[7] being the MSB and DT[0] being the LSB is rearranged so that the MSB is in DT[0] and the LSB  
is in DT[7] of the outgoing data stream DT[7:0]. In bit synchronous mode, DT[7] is the first bit transmitted. If packet  
processing is disabled the data stream is passed on to packet scrambling, bypassing FCS processing, packet error  
insertion, stuffing, packet abort sequence insertion, and inter-frame padding. If packet processing is disabled in bit  
synchronous mode, the serial data stream is demultiplexed in to an 8-bit data stream before being passed on.  
FCS processing calculates a FCS and appends it to the packet. FCS calculation is a CRC-16 or CRC-32  
calculation over the entire packet. The polynomial used for FCS-16 is x16 + x12 + x5 + 1. The polynomial used for  
FCS-32 is x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1. The FCS is inverted after  
calculation. The FCS type is programmable. If FCS append is enabled, the calculated FCS is appended to the  
packet. If FCS append is disabled, the packet is transmitted without a FCS. The FCS append mode is  
programmable. If packet processing is disabled, FCS processing is not performed.  
Packet error insertion inserts errors into the FCS bytes. A single FCS bit is corrupted in each errored packet. The  
FCS bit corrupted is changed from errored packet to errored packet. Error insertion can be controlled by a register  
or by the manual error insertion input (TMEI). The error insertion initiation type (register or input) is programmable.  
If a register controls error insertion, the number and frequency of the errors are programmable. If FCS append is  
disabled, packet error insertion will not be performed. If packet processing is disabled, packet error insertion is not  
performed.  
Stuffing inserts control data into the packet to prevent packet data from mimicking flags. Stuffing is performed from  
the beginning of a packet until the end of a packet. In bit synchronous mode, the 8-bit parallel data stream is  
multiplexed into a serial data stream, and bit stuffing is performed. Bit stuffing consists of inserting a '0' directly  
following any five contiguous '1's. In octet aligned mode, byte stuffing is performed. Byte stuffing consists of  
detecting bytes that mimic flag and escape sequence bytes (7Eh and 7Dh), and replacing the mimic bytes with an  
escape sequence (7Dh) followed by the mimic byte exclusive ORed with 20h. If packet processing is disabled,  
stuffing is not performed.  
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Inter-frame padding inserts start flags, end flags and inter-frame fill between packets. There will be at least one flag  
plus a programmable number of additional flags between packets. In octet aligned mode, the inter-frame fill is  
flags. In bit synchronous mode, the inter-frame fill can be flags or all 1s followed by a start flag. If the inter-frame fill  
is all '1's, the number of '1's between the end and start flags may not be an integer number of bytes, however,  
there will be at least 15 consecutive '1's between the end and start flags. The bit synchronous mode inter-frame  
padding type is programmable. If packet processing is disabled, inter-frame padding is not performed.  
Packet abort insertion inserts a packet abort sequences as necessary. If a packet abort indication is detected, a  
packet abort sequence is inserted and inter-frame padding is done until a packet start flag is detected. In bit  
synchronous mode, the abort sequence is FFh. In octet aligned mode, the abort sequence is 7D7Eh. If packet  
processing is disabled, packet abort insertion is not performed.  
The packet scrambler is a x43 + 1 self-synchronous scrambler that scrambles the entire packet data stream. Packet  
scrambling is programmable.  
Once all packet processing has been completed, in bit synchronous mode, the 8-bit parallel data stream is  
multiplexed into a serial data stream and passed on. In octet aligned mode, the 8-bit parallel data stream is passed  
on.  
8.3.6.2 Receive Packet Processor  
The Receive Packet Processor performs packet descrambling, packet delineation, inter-frame fill filtering, packet  
abort detection, destuffing, packet size checking, FCS error monitoring, FCS byte extraction, and bit reordering.  
The data coming in can be either a serial data stream or an 8-bit parallel data stream, depending on the framing  
mode The type of data stream received affects packet descrambling, packet delineation, inter-frame fill filtering,  
packet abort detection, and destuffing, however, it does not affect packet size checking, FCS error monitoring, FCS  
byte extraction, or bit reordering. Packet processing can be disabled (clear-channel enable). Disabling packet  
processing disables packet delineation, inter-frame fill filtering, packet abort detection, destuffing, packet size  
checking, FCS error monitoring, and FCS byte extraction. Only packet descrambling and bit reordering are not  
disabled.  
The packet descrambler is a self-synchronous x43 + 1 descrambler that descrambles the entire packet data stream.  
Packet descrambling is programmable. If packet processing is disabled in bit synchronous mode, the serial data  
stream is demultiplexed in to an 8-bit data stream before being passed on.  
If packet processing is disabled, a packet boundary is arbitrarily chosen, and the data is divided into "packets"  
whose size is programmable (maximum packet size setting). These packets are then passed on to bit reordering  
bypassing packet delineation, inter-frame fill filtering, packet abort detection, destuffing, packet size checking, FCS  
error monitoring, and FCS byte extraction.  
Packet delineation determines the packet boundary by identifying a packet start or end flag. Each time slot is  
checked for a flag sequence (7Eh). Once a flag is found, it is identified as a start or end flag, and the packet  
boundary is set. If packet processing is disabled, packet delineation is not performed.  
Inter-frame fill filtering removes the inter-frame fill between packets. When a packet end flag is detected, all data is  
discarded until a packet start flag is detected. In bit synchronous mode, the inter-frame fill can be flags or all '1's.  
When the interframe fill is all ‘1’s, the number of '1's between the start and end flags does not need to be an integer  
number of bytes. In bit synchronous mode when inter-frame fill is flags, there may be only one flag between  
packets, or the flags may have a shared zero (011111101111110). In octet aligned mode, the inter-frame fill can  
only be flags, and there may be only one flag between packets. If packet processing is disabled, inter-frame fill  
filtering is not performed.  
Packet abort detection searches for a packet abort sequence. Between a packet start flag and a packet end flag, if  
an abort sequence is detected, the packet is marked with an abort indication, the aborted packet count is  
incremented, and all subsequent data is discarded until a packet start flag is detected. In bit synchronous mode,  
the abort sequence is seven consecutive ones. In octet aligned mode, the abort sequence is 7D7Eh. If packet  
processing is disabled, packet abort detection is not performed.  
Destuffing removes the extra data inserted to prevent data from mimicking a flag or an abort sequence. In bit  
synchronous mode, bit destuffing is performed. Bit destuffing consists of discarding any '0' that directly follows five  
contiguous '1's. In octet aligned mode, byte destuffing is performed. Byte destuffing consists of detecting an  
escape sequence (7Dh), discarding it and exclusive ORing the next byte with 20h. In bit synchronous mode, after  
destuffing is completed, the serial bit stream is demultiplexed into an 8-bit parallel data stream and passed on to  
packet size checking. If there is less than eight bits in the last byte, an invalid packet flag is raised, the packet is  
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tagged with an abort indication, and the packet size violation count is incremented. In octet aligned mode, after  
destuffing is completed, the 8-bit parallel data stream is passed on to packet size checking. If packet processing is  
disabled, destuffing is not performed.  
Packet size checking checks each packet for a programmable maximum and programmable minimum size. As the  
packet data comes in, the total number of bytes is counted. If the packet length is below the minimum size limit, the  
packet is marked with an aborted indication, and the packet size violation count is incremented. If the packet length  
is above the maximum size limit, the packet is marked with an aborted indication, the packet size violation count is  
incremented, and all packet data is discarded until a packet start is received. The minimum and maximum lengths  
include the FCS bytes, and are determined after destuffing has occurred. If packet processing is disabled, packet  
size checking is not performed.  
FCS error monitoring checks the FCS and aborts errored packets. If a FCS error is detected, the FCS errored  
packet count is incremented and the packet is marked with an aborted indication. The FCS type (16-bit or 32-bit) is  
programmable. If FCS processing or packet processing is disabled, FCS byte extraction is not performed.  
FCS byte extraction discards the FCS bytes. If FCS extraction is enabled, the FCS bytes are extracted from the  
packet and discarded. If FCS extraction is disabled, the FCS bytes are stored in the receive FIFO with the packet.  
If FCS processing or packet processing is disabled, FCS byte extraction is not performed.  
Bit reordering changes the bit order of each byte. If bit reordering is enabled, the incoming 8-bit data stream  
DT[7:0] with DT[7] being the MSB and DT[0] being the LSB is rearranged so that the MSB is in DT[0] and the LSB  
is in DT[7] of the outgoing FIFO data stream DT[7:0]. In bit synchronous mode, DT[7] is the first bit received.  
Once all packet processing has been completed, the 8-bit parallel data stream is demultiplexed into a 32-bit  
parallel data stream and passed on to the Receive FIFO.  
8.3.7 FIFO  
8.3.7.1 Transmit FIFO  
The Transmit FIFO block contains memory for 64 32-bit data words. The Transmit FIFO separates the transmit  
system interface timing from the transmit physical interface timing. The Transmit FIFO functions include filling the  
memory, tracking the memory fill level, maintaining the memory read and write pointers, and detecting memory  
overflow and underflow conditions. The number of data transfers that can occur after the Transmit FIFO "full"  
indication is deasserted is programmable. The Transmit FIFO port address used for selection and polling by the  
Transmit System Interface Bus Controller is programmable. In system loopback, the data from the Transmit FIFO  
is looped back to the Receive FIFO, and a FIFO empty indication is passed on to the Transmit Cell/Packet  
Processor.  
In cell processing mode, all operations are cell based. The Transmit FIFO is considered empty when it does not  
contain any data. The Transmit FIFO is considered "almost empty" when it does not contain a cell. The Transmit  
FIFO is considered "almost full" when it does not have space available to store a programmable number of cells.  
The Transmit FIFO is considered full when it does not have space available for a complete cell. When the  
Transmit FIFO level drops below the “almost full” indication, the TDXA[n] is asserted. The Transmit FIFO accepts  
cell transfers from the Transmit System Interface Bus Controller until it is full. If a start of cell is received while full,  
the cell is discarded and a FIFO overflow condition is declared. Once a FIFO overflow condition is declared, the  
Transmit FIFO will discard cell data until a start of cell is received while the FIFO has more space available than  
the "almost full" level. If the Transmit FIFO receives cell data other than a start of cell after a complete cell has  
been received, an invalid transfer is declared and all cell data is discarded until a start of cell is received. If a start  
of cell is received before a previous cell transfer has been completed, the current cell is discarded and a short  
transfer is declared. The new cell is processed normally. If the Transmit Cell Processor attempts a read while the  
Transmit FIFO is empty, a FIFO underflow condition is declared. Once a FIFO underflow condition is declared, the  
Transmit FIFO data will be discarded until a start of cell is received.  
In packet processing mode, all operations are byte based. The Transmit FIFO is considered empty when its  
memory does not contain any data. The Transmit FIFO is considered "almost empty" when its memory does not  
contain a packet end and there is a programmable number of bytes or less stored in the memory. The Transmit  
FIFO is considered "almost full" when its memory has a programmable number of bytes or less available for  
storage. When the Transmit FIFO has more bytes available for storage than the “almost full” level the TDXA[n] or  
TPXA pin will be asserted to signal to the POS device that it is ready to receive more packet data. The Transmit  
FIFO is considered full when it does not have any space available for storage. When the Transmit FIFO is full, the  
TDXA[n] pin will be deasserted. The Transmit FIFO accepts data from the Transmit System Interface Bus  
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Controller until full. If a start of packet or short packet (32-bit data word with a start of packet and end of packet) is  
received while full, the data is discarded and a FIFO overflow condition is declared. If any other packet data is  
received while full, the current packet being transferred is marked with an abort indication, and a FIFO overflow  
condition is declared. Once a FIFO overflow condition is declared, the Transmit FIFO will discard data until a start  
of packet is received while the FIFO has more space available than the "almost full" level. If a packet error (a  
transfer with TERR and TEOP asserted) is received from the Transmit System Interface Bus Controller, an aborted  
transfer is declared, the data is stored in memory with a packet abort indication, and the Transmit FIFO will discard  
data until a start of packet is received. If an end of a packet has been received and the Transmit FIFO receives  
packet data other than a start of packet, an invalid transfer is declared, and all packet data is discarded until a start  
of packet is received. If a start of packet is received before a previous packet transfer has been completed (an end  
of packet was never received), the current packet being transferred is marked with an abort indication and a short  
transfer is declared. The new packet is processed normally. If the Transmit Packet Processor attempts a read  
while the Transmit FIFO is empty, a FIFO underflow condition is declared. Once a FIFO underflow condition is  
declared, the Transmit FIFO data will be discarded until a start of cell is received.  
8.3.7.2 Receive FIFO  
The Receive FIFO block contains memory for 64 32-bit data words. The Receive FIFO separates the receive  
system interface timing from the receive physical interface timing. The Receive FIFO functions include filling the  
memory, tracking the memory fill level, maintaining the memory read and write pointers, and detecting memory  
overflow and underflow conditions. The Receive FIFO port address used for selection and polling by the Receive  
System Interface Bus Controller is programmable. In system loopback, data is looped back from the Transmit FIFO  
to the Receive FIFO.  
In cell processing mode, all operations are cell based. The Receive FIFO is considered empty unless it contains a  
cell. The Receive FIFO is considered "almost empty" when it contains a programmable number of cells or less.  
When the Receive FIFO level has more data available for transfer than the “almost empty” level, the RDXA[n] pin is  
asserted. The Receive FIFO is considered "almost full" when it does not have space available to store a complete  
cell. The Receive FIFO is considered full when it does not have any space available. The Receive FIFO accepts  
cell data from the Receive Cell Processor until full. If cell data is received while the FIFO is full, the cell is discarded  
and a FIFO overflow condition is declared. Once a FIFO overflow condition is declared, the Receive FIFO will  
discard cell data until a cell start is received while the FIFO has space available to store a complete cell. If the  
Receive System Interface Bus Controller attempts a read while the FIFO is empty, the read is ignored.  
In packet processing mode, all operations are 32-bit word based. The Receive FIFO is considered empty when it  
does not contain any data. The Receive FIFO is considered "almost empty" when its memory does not contain a  
packet end and there is a programmable number of words or less stored in the memory. When the Receive FIFO  
has more bytes available for transfer than the “almost empty” level or has an end of packet, the RDXA[n] pin is  
asserted (POS-PHY Level 2). The Receive FIFO is considered "almost full" when its memory has a programmable  
number of words or less available for storage. The Receive FIFO is considered full when it does not have any  
space available for storage. The Receive FIFO accepts data from the Receive Packet Processor until full. If a  
packet start or short packet is received while full, the data is discarded and a FIFO overflow condition is declared. If  
any other packet data (packet end or middle) is received while full, the current packet being received is marked  
with an abort indication, and a memory overflow condition is declared. Once a memory overflow condition is  
declared, the Receive FIFO will discard data until a packet start is received while the FIFO has more space  
available than the "almost full" level. If the Receive System Interface Bus Controller attempts a read while the FIFO  
is empty, the read is ignored.  
8.3.8  
System Loopback  
There is a system loopback available in the ATM/HDLC Mapper. The loopback can be performed on a per-port  
basis. When a port is placed in system loopback, the data coming in from the System Interface is looped back from  
the Transmit FIFO to the Receive FIFO, a FIFO empty indication is passed on to the Transmit Cell/Packet  
Processor, and all data coming from the Receive Cell/Packet Processor is discarded. The maximum throughput of  
a single port is limited to half of the Receive System Interface bandwidth in 16-bit mode. A loss of data may occur if  
the Cell Packet Receive clock (RSCLK) has a frequency that is greater than one and one half times the Cell Packet  
Transmit clock (TSCLK).  
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8.4 T1 Receive Framer Description and Operation  
The DS26556 includes four fully independent DS1/E1 framers. Each framer can be individually programmed to  
accept AMI, B8ZS, HDB3, or NRZ data. In T1 mode, each framer supports D4 (SF), ESF, and SLC-96 frame  
formats, and detects/reports common alarms such as AIS, RAI, LOS, and OOF, as well as AIS-CI and RAI-CI.  
Performance monitor counters are maintained for each port, which report bipolar/line-code violations, F-bit/CRC  
errors, and number of out-of-sync multiframes.  
Each framer has an HDLC controller that can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 mode), or  
the FDL (T1 mode), and has 64-byte FIFO buffers in both the transmit and receive paths.  
The HDLC controllers perform the necessary overhead for generating and receiving performance report messages  
(PRM) as described in ANSI T1.403 and the messages as described in AT&T TR54016. The HDLC controllers  
automatically generate and detect flags; generate and check the CRC checksum; generate and detect abort  
sequences and stuff and destuff zeros; and byte align to the data stream. The FIFO buffers are large enough to  
allow a full PRM to be received or transmitted without host intervention.  
Other features contained within each framer include a BOC detector with programmable code integration and three  
independent 16-bit loop-code detectors. Host interface is simplified with status registers optimized for either  
interrupt driven or polled environments. In many cases, status bits are reported in both real-time and latched on  
change-of-state with separate bits for each state change. Most latched bits can be mapped to generate an external  
interrupt on the INT pin.  
8.4.1 T1 Loopbacks  
Figure 8-8 Remote Loopback  
RECEIVE  
FRAMER  
BACKPLANE  
I/F  
TRANSMIT  
FRAMER  
BACKPLANE  
I/F  
REMOTE LOOPBACK  
In this loopback, data input at the RTIP and RRING pins is transmitted back to the TTIP and TRING pins. Data  
continues to pass through the DS26556’s receive-side framer as it would normally, and the data from the transmit-  
side formatter is ignored.  
Figure 8-9 Payload Loopback  
RECEIVE  
FRAMER  
BACKPLANE  
I/F  
TRANSMIT  
FRAMER  
BACKPLANE  
I/F  
PAYLOAD LOOPBACK  
(CAN BE DONE ON A PER-CHANNEL BASIS)  
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When PLB is enabled, the following occurs:  
1) Data is transmitted from the TTIP and TRING pins synchronous with RCLK instead of TCLK.  
2) All the receive-side signals continue to operate normally.  
3) TCHMKR is forced low.  
4) Data at the TDATAI pin is ignored.  
Normally, this loopback is only enabled when ESF framing is being performed, but it can also be enabled in D4  
framing applications. In a PLB situation, the DS26556 loops the 192 bits of payload data (with BPVs corrected)  
from the receive section back to the transmit section. The FPS framing pattern, CRC6 calculation, and the FDL bits  
are not looped back, they are reinserted by the DS26556.  
Figure 8-10 Framer Loopback  
RECEIVE  
FRAMER  
BACKPLANE  
I/F  
TRANSMIT  
FRAMER  
BACKPLANE  
I/F  
FRAMER LOOPBACK  
This loopback is useful in testing and debugging applications. In FLB, the DS26556 loops data from the transmit  
side back to the receive side. When FLB is enabled, the following occurs:  
1) (T1 mode) An unframed all-ones code is transmitted at TTIP and TRING.  
(E1 mode) Normal data is transmitted at TTIP and TRING.  
2) Data at RTIP and RRING is ignored.  
3) All receive-side signals take on timing synchronous with TCLK instead of RCLK.  
8.4.2 H.100 (CT Bus) Compatibility  
The H.100 (or CT Bus) is a synchronous, bit-serial, TDM transport bus operating at 8.192MHz. The H.100 standard  
also allows compatibility modes to operate at 2.048MHz, 4.096MHz, or 8.192MHz. The control bit, H100EN  
(RIOCR.5), when combined with HSSYNCINV, allows the DS26556 to accept a CT-Bus-compatible frame-sync  
signal (CT_FRAME) at the HSSYNC input. The following rules apply to the H100EN control bit:  
1) The H100EN bit controls the sampling point for the HSSYNC input signal only.  
2) The H100EN bit does not invert the expected signal; HSSYNCINV (TIOCR) must be set high to invert the  
inbound sync signal.  
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Figure 8-11 HSSYNC Input in H.100 (CT Bus) Mode  
HSSYNC1  
HSSYNC2  
HSYSCLK  
HTDATA,  
HRDATA  
Bit 8  
Bit 1  
Bit 2  
3
tbc  
NOTE 1: HSSYNC IN NORMAL OPERATION.  
NOTE 2: HSSYNC WITH H100EN = 1 and HSSYNCINV = 1.  
NOTE 3: tbc (BIT-CELL TIME) = 122ns (typ). tbc = 244ns or 488ns ALSO ACCEPTABLE.  
8.4.3 T1 Receive Status and Information  
When a particular event has occurred (or is occurring), the appropriate bit in one of these registers is set to 1.  
Status bits can operate in either a latched or real-time fashion. Some latched bits can be enabled to generate a  
hardware interrupt through the INT signal.  
Real-Time Bits  
Some status bits operate in a real-time fashion. These bits are read-only and indicate the present state of an alarm  
or a condition. Real-time bits remain stable and valid during the host read operation. The current value of the  
internal status signals can be read at any time from the real-time status registers without changing any of the  
latched status register bits.  
Latched Bits  
When an event or an alarm occurs and a latched bit is set to 1, it remains set until the user clears it. These bits  
typically respond on a change-of-state for an alarm, condition, or event, and operate in a read-then-write fashion.  
The user should read the value of the desired status bit and then write a 1 to that particular bit location to clear the  
latched value (write a zero to locations not to be cleared). Once the bit is cleared, it is not set again until the event  
has occurred again.  
Mask Bits  
Some of the alarms and events can be either masked or unmasked from the interrupt pin through the interrupt  
mask registers (RIMx). When unmasked, the INT signal is forced low when the enabled event or condition occurs.  
The INT pin is allowed to return high (if no other unmasked interrupts are present) when the user reads, then clears  
(with a write) the alarm bit that caused the interrupt to occur. Note that the latched status bit and the INT pin clear  
even if the alarm is still present.  
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Note that some conditions can have multiple status indications. For example, receive loss-of-frame (RLOF)  
provides the following indications:  
Real-time indication that the receiver is not  
RRTS1.0  
(RLOF)  
synchronized with incoming data stream. Read-only  
bit that remains high as long as the condition is  
present.  
Latched indication that the receiver has lost  
synchronization since the bit was last cleared. Bit  
will clear when written by the user, even if the  
condition is still present (rising edge detect of  
RRTS1.0).  
RLS1.0  
(RLOFD)  
Latched indication that the receiver has reacquired  
synchronization since the bit was last cleared. Bit  
will clear when written by the user, even if the  
condition is still present (falling edge detect of  
RRTS1.0).  
RLS1.4  
(RLOFC)  
Table 8-1 T1 Alarm Criteria  
ALARM  
SET CRITERIA  
CLEAR CRITERIA  
When over a 3ms window, 5 or fewer When over a 3ms window, 6 or more  
AIS (Blue Alarm) (Note 1)  
zeros are received  
zeros are received  
RAI (Yellow Alarm)  
1) D4 Bit 2 Mode  
(RCR2.0 = 0)  
When bit 2 of 256 consecutive  
channels is set to zero for at least  
254 occurrences  
When bit 2 of 256 consecutive channels  
is set to zero for less than 254  
occurrences  
2) D4 12th F-Bit Mode  
(RCR2.0 = 1; also referred to  
as the Japanese Yellow  
Alarm)  
When the 12th framing bit is set to  
one for two consecutive occurrences for two consecutive occurrences  
When the 12th framing bit is set to zero  
When 16 consecutive patterns of  
00FF appear in the FDL  
When 14 or less patterns of 00FF hex  
out of 16 possible appear in the FDL  
3) ESF Mode  
When 14 or more ones out of 112  
possible bit positions are received  
starting with the first one received  
LOS (also referred to as  
Receive Carrier Loss (RCL))  
When 192 consecutive zeros are  
received  
Note 1: The definition of the Alarm Indication Signal (Blue Alarm) is an unframed all-ones signal. AIS detectors  
should be able to operate properly in the presence of a 10E-3 error rate, and they should not falsely trigger on a  
framed all-ones signal. The AIS alarm criteria in the DS26556 has been set to achieve this performance. It is  
recommended that the RAIS bit be qualified with the RLOF bit.  
Note 2: The following terms are equivalent:  
RAIS = Blue Alarm  
RLOS = RCL  
RLOF = Loss of Frame  
RRAI = Yellow Alarm  
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8.4.4 Receive AIS-CI and RAI-CI Detection  
AIS-CI is a repetitive pattern of 1.26 seconds. It consists of 1.11 seconds of an unframed all ones pattern and 0.15  
seconds of all ones modified by the AIS-CI signature. The AIS-CI signature is a repetitive pattern 6176 bits in  
length in which, if the first bit is numbered bit 0, bits 3088, 3474 and 5790 are logical zeros and all other bits in the  
pattern are logical ones (T1.403). AIS-CI is an unframed pattern and therefore is defined for all T1 framing formats.  
The RAIS-CI bit is set when the AIS-CI pattern has been detected and RAIS (RRTS1.2) is set. RAIS-CI is a latched  
bit and should be cleared by the host when read. RAIS-CI will continue to set approximately every 1.2 seconds  
that the condition is present. The host will need to ‘poll’ the bit, in conjunction with the normal AIS indicators to  
determine when the condition has cleared.  
RAI-CI is a repetitive pattern within the ESF data link with a period of 1.08 seconds. It consists of sequentially  
interleaving 0.99 seconds of “00000000 11111111” (right-to-left) with 90ms of “00111110 11111111”. The RRAI-CI  
bit is set when a bit-oriented code of “00111110 11111111” is detected while RRAI (RRTS1.3) is set. The RRAI-CI  
detector uses the receive BOC filter bits (RBF0 & RBF1) located in RBOCC to determine the integration time for  
RAI-CI detection. Like RAIS-CI, the RRAI-CI bit is latched and should be cleared by the host when read. RRAI-CI  
will continue to set approximately every 1.1 seconds that the condition is present. The host will need to ‘poll’ the bit,  
in conjunction with the normal RAI indicators to determine when the condition has cleared. It may be useful to  
enable the 200ms ESF RAI integration time with the RAIIE control bit (RCR2.1) in networks that use RAI-CI.  
8.4.5 T1 Receive-Side Digital Milliwatt Code Generation  
Receive-side digital milliwatt code generation involves using the receive-digital milliwatt registers (T1RDMR1/2/3)  
to determine which of the 24 T1 channels of the T1 line going to the backplane should be overwritten with a digital  
milliwatt pattern. The digital milliwatt code is an 8-byte repeating pattern that represents a 1kHz sine wave  
(1E/0B/0B/1E/9E/8B/8B/9E). Each bit in the T1RDMRx registers, represents a particular channel. If a bit is set to 1,  
then the receive data in that channel is replaced with the digital milliwatt code. If a bit is set to zero, no replacement  
occurs.  
8.4.6 T1 Error Count Registers  
The DS26556 contains three T1 performance counters that are used to accumulate line coding errors, path errors,  
and synchronization errors. Counter update options include one-second boundaries, 42ms (T1 mode only), 62.5ms  
(E1 mode only), or manually. See the Error Counter Configuration Register (ERCNT) section. When updated  
automatically, the user can use the interrupt from the timer to determine when to read these registers. The line-  
code violation count register has the potential to saturate, but the bit error would have to exceed 10E-2 before this  
would occur. All other counters roll over.  
Several options are available for latching the performance counters:  
1) Each framer’s counters are latched independently based on independent one-second interval timers.  
2) Each framer’s counters are latched independently based on independent 42ms interval timers.  
3) Each framer’s counters are latched independently with a low-to-high transition on the respective MECU control  
bit.  
4) Counters from selected framers are latched synchronously at the one-second interval supplied by Framer #1.  
5) Counters from selected framers are synchronously latched manually with the global counter latch-enable  
(GCLE) bit in GCR1.  
The following table shows control bit settings in the ERCNT register to support each of the five modes discussed  
above.  
Control Bit  
EAMS  
ECUS  
MECU  
MCUS  
1SECS  
Mode 1  
Mode 2  
Mode 3  
Mode 4  
Mode 5  
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
X
0 to 1  
0
0
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8.4.7 T1 Receive Signaling Operation  
There are two methods of accessing receive-signaling data: through processor-based (i.e., software-based)  
signaling or hardware-based signaling. Processor-based refers to access through the receive-signaling registers,  
RS1 through RS12. Hardware-based refers to the HRSIG pin. Hardware based signaling is available only when the  
port is configured in the multiplexed bus mode utilizing the high speed TDM port. Both methods can be used  
simultaneously. NOTE: The receive framer does not normally remove robbed-bit signaling from the data  
stream. Signaling information is present in the data stream at the RSER pin unless the receive framer has  
been programmed to over-lay certain channels with idle codes or to force signaling bit positions to a “one”  
state. The signaling data in data stream at the HRDATA pin can be re-aligned to a users multiframe  
reference. See Signaling Re-insertion below.  
8.4.8 Software Signaling  
Robbed-bit signaling (the LSB of each channel during frames 6, 12, 18 and 24 in ESF mode and frames 6 and 12  
in D4 mode ) is sampled in the receive data stream and copied into the receive-signaling registers, RS1 through  
RS12. The signaling information in these registers is always updated on multiframe boundaries. This function is  
referred to as “Software Based Signaling” and is always enabled. The signaling bit position of each channels is  
sampled even thought the channel may not be carrying signaling information. The user may simply ignore these  
channels.  
8.4.8.1 Change of State  
To avoid constant monitoring of the receive-signaling registers, the DS26556 can be programmed to alert the host  
when any specific channel or channels undergo a change of their signaling state. For T1, RSCSE1 through  
RSCSE3 are used to select which channels can cause a change-of-state indication. The change of state is  
indicated in latched status register 4 (RLS4.3). The user can enable the INT pin to toggle low upon detection of a  
change in signaling by setting the interrupt mask bit RIM4.3.  
The user can identify which channels have undergone a signaling change of state by reading the receive-signaling  
status (RSS1–RSS3) registers. The information from these registers tells the user which RSx register to read for  
the new signaling data. All changes are indicated in the RSS1 through RSS3 registers regardless of the state of t  
he RSCSE1 through RSCSE3 registers.  
8.4.9 Hardware Signaling  
A TDM signaling stream is available via the HRSIG pin when the port is configured to use the high speed  
multiplexed TDM bus. HRSIG is a signaling-PCM stream output on a channel-by-channel basis from the signaling  
buffer and multiplexed with any other port configured to use the high speed TDM bus. In ESF mode the HRSIG  
data is updated once a multiframe (3ms) unless a freeze is in effect. In the D4 framing mode, the AB signaling bits  
are output twice on RSIG in the lower nibble of each channel. Hence, bits 5 and 6 contain the same data as bits 7  
and 8, respectively, in each channel. The HRSIG data is updated once a multiframe (1.5ms) unless a freeze is in  
effect.  
8.4.9.1 Signaling Debounce  
When signaling integration is enabled (RSIGC.0 = 1), the signaling data at the HRSIG pin is automatically  
debounced. Signaling must be constant for three multiframes before being updated at HRSIG. Signaling debounce  
is enabled on a global basis (all channels or none). NOTE: This feature is available only on the high speed  
TDM bus.  
8.4.10 Signaling Re-insertion  
The signaling buffer allows signaling data to be reinserted into the original data stream in a different alignment  
determined by a multiframe sync signal from the HSSYNC pin. Registers RSI1 through RSI4 are used to select  
signaling re-insertion on a channel-by-channel basis. Ports configured to be multiplexed on the high speed TDM  
bus can have the same signaling alignment. In T1 mode re-insertion generally results in there being two copies of  
robbed signaling for each port in the data stream, one at the original position and one at the user defined position.  
NOTE: It is possible to configure only one port to the high speed multiplexed bus. In this case the RSER  
pin for that port and the HRDATA pin are duplicates.  
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8.4.11 Receive Signaling Freeze  
NOTE: This feature is available only on the high speed TDM bus. The signaling data in the four multiframe  
signaling buffer will be frozen in a known good state upon either a loss of framing (RLOF), carrier loss (RLOS), or  
change of frame alignment (COFA). To allow this freeze action to occur, the RSFE control bit (RSIGC.1) should be  
set high. The user can force a freeze by setting the RSFF control bit (RSIGC.2) high. The four multiframe buffer  
provides a three multiframe delay in the signaling bits provided at the HRSIG pin (and at the HRDATA pin if receive  
signaling reinsertion is enabled). When freezing is enabled (RSFE = 1), the signaling data will be held in the last  
known good state until the error condition subsides. The signaling data will be held in the old state for at least an  
additional 6ms before being allowed to update with new signaling data.  
8.4.12 Fractional T1 Support (Gapped-Clock Mode)  
The DS26556 can be programmed to output gapped clocks for selected channels in the receive and transmit  
paths. When the gapped-clock feature is enabled, a gated clock is output on the RCHMRK pin. The channel  
selection is controlled through the receive-gapped-clock channel-select registers (RGCCS1–RGCCS4). The  
receive path is enabled for gapped-clock mode with the RGCE bit (RESCR.6). Both 56kbps and 64kbps channel  
formats are supported as determined by RESCR.7. When 56kbps mode is selected, the clock corresponding to the  
data/control bit in the channel is omitted (only the seven most significant bits of the channel have clocks).  
8.4.13 T1 Bit-Oriented Code (BOC) Controller  
The DS26556 contains a BOC generator on the transmit side and a BOC detector on the receive side. The BOC  
function is available only in T1 mode.  
In ESF mode, the DS26556 continuously monitors the receive message bits for a valid BOC message. The BOC-  
detect (BD) status bit at RLS7.0 is set once a valid message has been detected for time determined by the receive-  
BOC-filter bits RBF0 and RBF1 in the RBOCC register. The 6-bit BOC message is available in the RBOC register.  
Once the user has cleared the BD bit, it remains clear until a new BOC is detected (or the same BOC is detected  
following a BOC-clear event). The BOC-clear (BC) bit at RLS7.1 is set when a valid BOC is no longer being  
detected for a time determined by the receive-BOC-disintegration bits RBD0 and RBD1 in the RBOCC register.  
The BD and BC status bits can create a hardware interrupt on the INT signal as enabled by the associated  
interrupt mask bits in the RIM7 register.  
8.4.14 Receive SLC-96 Operation  
In an SLC-96-based transmission scheme, the standard Fs-bit pattern is robbed to make room for a set of  
message fields. The SLC-96 multiframe is made up of six D4 superframes, hence it is 72 frames long. In the 72-  
frame SLC-96 multiframe, 36 of the framing bits are the normal Ft pattern and the other 36 bits are divided into  
alarm, maintenance, spoiler, and concentrator bits, as well as 12 bits of the normal Fs pattern. Additional SLC-96  
information can be found in BellCore document TR–TSY–000008.  
To enable the DS26556 to synchronize onto an SLC-96 pattern, the following configuration should be used:  
Set to D4 framing mode (RCR1.5 = 1)  
Set to cross-couple Ft and Fs bits (RCR1.3 = 1)  
Enable SLC-96 synchronizer (RCR2.4 = 1)  
Set to minimum sync time (RCR1.7 = 0)  
The status bit RSLC96 located at RLS7.3 is useful for retrieving SLC-96 message data. The RSLC96 bit indicates  
when the framer has received the 12-bit Fs-alignment pattern and updated the data-link registers RSLC1–RSLC3  
with the latest message data from the incoming data stream. Once the RSLC96 bit is set, the user has 2ms to  
retrieve the most recent message data from the RSLC1/2/3 registers. Note that RSLC96 is not set if the DS26556  
is unable to detect the 12-bit SLC-96 alignment pattern.  
8.4.15 Receive FDL  
In the receive section, the recovered FDL bits or Fs bits are shifted bit-by-bit into the receive FDL register (RFDL).  
Since the RFDL is 8 bits in length, it fills up every 2ms (8 x 250μs). The framer signals an external microcontroller  
that the buffer has filled through the RLS7.2 bit. If enabled through RIM7.2, the INT pin toggles low, indicating that  
the buffer has filled and needs to be read. The user has 2ms to read this data before it is lost. Note that no zero  
destuffing is applied for the data provided through the RFDL register.  
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8.4.16 Programmable In-Band Loop-Code Detection  
The DS26556 can generate and detect a repeating bit pattern from 1 to 8 bits or 16 bits in length. This function is  
available only in T1 mode. The framer has three programmable pattern detectors. Typically, two of the detectors  
are used for loop-up and loop-down code detection. The user programs the codes to be detected in the receive-up-  
code definition (RUPCD1 and RUPCD2) registers and the receive-down-code definition (RDNCD1 and RDNCD2)  
registers, and the length of each pattern is selected through the RIBCC register. A third detector (spare) is defined  
and controlled through the RSPCD1/RSPCD2 and RSCC registers. When detecting a 16-bit pattern, both receive-  
code-definition registers are used together to form a 16-bit register. For 8-bit patterns, both receive-code-definition  
registers are filled with the same value. Detection of a 1-, 2-, 3-, 4-, 5-, 6-, and 7-bit pattern only requires the first  
receive-code-definition register to be filled. The framer detects repeating pattern codes in framed and unframed  
circumstances with bit-error rates as high as 10E-2. The detectors can handle F-bit-inserted and F-bit-overwrite  
patterns. Writing the least significant byte of the receive-code-definition register resets the integration period for  
that detector. The code detector has a nominal integration period of 36ms. Therefore, after about 36ms of receiving  
a valid code, the proper status bit (LUP, LDN, and LSP) is set to 1. Note that real-time status bits, as well as  
latched set and clear bits, are available for LUP, LDN, and LSP (RRTS3 and RLS3). Normally codes are sent for 5  
seconds. It is recommended that the software poll the framer every 50ms to 1000ms until 5 seconds has elapsed  
to ensure the code is continuously present.  
8.4.17 Receive HDLC Controller  
The HDLC controller can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 mode), or the FDL (T1 mode).  
The HDLC controller has a 64-byte FIFO buffer in the transmit and receive paths. The user can select any specific  
bits within the time slot(s) to assign to the HDLC controller, as well as specific Sa bits (E1 mode).  
The HDLC controller performs the necessary overhead for generating and receiving performance report messages  
(PRM) as described in ANSI T1.403 and the messages as described in AT&T TR54016. The HDLC controller  
automatically generates and detects flags; generates and checks the CRC checksum; generates and detects abort  
sequences and stuffs and destuffs zeros; and byte aligns to the data stream. The 64-byte buffers in the HDLC  
controller are large enough to allow a full PRM to be received or transmitted without host intervention.  
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8.4.18 Receive HDLC Controller Example  
The HDLC status registers in the DS26556 allow for flexible software interface to meet the user’s preferences.  
When receiving HDLC messages, the host can choose to be interrupt-driven, or to poll to desired status registers,  
or a combination of polling and interrupt processes can be used. shows an example routine for using the DS26556  
HDLC receiver.  
Figure 8-12 Receive HDLC Example  
Configure Receive  
HDLC Controller  
(RHC, RHBSE, RHFC)  
Reset Receive  
HDLC Controller  
(RHC.6)  
Start New  
Message Buffer  
Enable Interrupts  
RPE and RHWM  
No Action Required  
Work Another Process  
NO  
Interrupt?  
YES  
Read Register  
RHPBA  
Read N Bytes From  
Rx HDLC FIFO (RHF)  
N = RHPBA[5..0]  
NO  
MS = 0?  
(MS = RHPBA[7])  
YES  
Read RRTS5 for  
Packet Status (PS2..0)  
Take appropriate action  
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8.5 T1 Transmit Formatter Description and Operation  
Four fully independent DS1/E1 transmit formatters are included within the DS26556. Each port can be individually  
programmed to transmit AMI, B8ZS, HDB3, or NRZ data. In T1 mode each formatter supports D4 (SF), ESF, and  
SLC-96 frame formats, and transmits common alarms such as AIS, RAI, AIS-CI, and RAI-CI.  
Each framer also has an HDLC controller which can be mapped into a single time slot, or Sa4 to Sa8 bits (E1  
Mode) or the FDL (T1 Mode) and has 64 byte FIFO buffers in both the transmit and receive paths. The user can  
select any specific bits within the time slot(s) to assign to the HDLC controllers, as well as specific Sa bits (E1  
Mode).  
The HDLC controllers perform all the necessary overhead for generating and receiving Performance Report  
Messages (PRM) as described in ANSI T1.403 and the messages as described in AT&T TR54016. The controllers  
automatically generate and detects flags, generate and check the CRC check sum, generate and detect abort  
sequences, stuff and de-stuff zeros, and byte align to the data stream. The large FIFO buffers allow a full PRM to  
be received or transmitted without host intervention.  
Other features contained within each framer include a BOC generator and a 16-bit loop code generator. Host  
interface is simplified with status registers optimized for either interrupt driven or polled environments. In many  
cases, status bits are reported both real-time and latched on change-of-state with separate bits for each state  
change. Most latched bits can be enabled to generate an external interrupt on the INT pin.  
Additional details concerning the operation of the DS1 formatter are included within the register descriptions within  
this section.  
8.5.1 T1 Per-Channel Loopback  
The Per-Channel Loopback Registers (PCLRs) determine which channels (if any) from the backplane should be  
replaced with the data from the receive side or in other words, off of the T1 or E1 line. If this loopback is enabled,  
then transmit and receive clocks and frame syncs must be synchronized. One method to accomplish this would be  
to tie RCLK to TCLK and RFSYNC to TSYNC. There are no restrictions on which channels can be looped back or  
on how many channels can be looped back.  
8.5.2 T1 Transmit DS0 Monitoring Function  
The DS26556 has the ability to monitor one DS0 (64kbps) channel in the transmit direction and one DS0 channel  
in the receive direction at the same time. In the transmit direction the user will determine which channel is to be  
monitored by properly setting the TCM0 to TCM4 bits in the TDS0SEL register. In the receive direction, the RCM0  
to RCM4 bits in the RDS0SEL register need to be properly set. The DS0 channel pointed to by the TCM0 to TCM4  
bits will appear in the Transmit DS0 Monitor (TDS0M) register and the DS0 channel pointed to by the RCM0 to  
RCM4 bits will appear in the Receive DS0 (RDS0M) register. The TCM4 to TCM0 and RCM4 to RCM0 bits should  
be programmed with the decimal decode of the appropriate T1or E1 channel. T1 channels 1 through 24 map to  
register values 0 through 23. E1 channels 1 through 32 map to register values 0 through 31. For example, if DS0  
channel 6 in the transmit direction and DS0 channel 15 in the receive direction needed to be monitored, then the  
following values would be programmed into TDS0SEL and RDS0SEL:  
TCM[4:0] = 00101  
RCM[4:0] = 01110  
8.5.3 T1 Transmit Signaling Operation  
There are two methods of providing transmit signaling data—processor-based (i.e., software-based) or hardware-  
based. Processor-based refers to access through the transmit signaling registers, TS1 through TS12, while  
hardware-based refers to using the HTSIG pins. Hardware based signaling is available only when the port is  
configured in the multiplexed bus mode utilizing the high speed TDM port. Both methods can be used  
simultaneously. Note: Signaling data may already be imbedded in the transmit data streams at the TSER or  
HTDATA pins. In this case the two methods mentioned above may be used to update any or all channels.  
8.5.3.1 Software Signaling  
Signaling data is loaded into the Transmit Signaling registers (TS1–TS12) via the host interface. On multiframe  
boundaries, the contents of these registers are loaded into a shift register for placement in the appropriate bit  
position in the outgoing data stream. The user can utilize the Transmit Multiframe Interrupt in Latched Status  
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Register 1 (TLS1.2) to know when to update the signaling bits. The user need not update any transmit signaling  
register for which there is no change of state for that register.  
Each Transmit Signaling Register contains the robbed bit signaling for two time slots that will be inserted into the  
outgoing stream if enabled to do so via TCR1.6. Signaling data can be sourced from the TSx registers on a per-  
channel basis by utilizing the Software Signaling Insertion Enable registers, SSIE1 through SSIE3.  
In T1 ESF framing mode, there are four signaling bits per channel (A, B, C, and D). TS1 through TS12 contain a  
full multiframe of signaling data. In T1 D4 framing mode, there are only two signaling bits per channel (A and B). In  
T1 D4 framing mode, the framer uses A and B bit positions for the next multiframe. The C and D bit positions  
become ‘don’t care’ in D4 mode.  
8.5.3.2 Hardware Signaling  
Hardware signaling is only available when the port is configured to use the high speed TDM bus. Note: the  
cell/packet interface is unavailable to this port in this mode. In hardware mode, signaling data is input via the  
HTSIG pin. This signaling PCM stream is demultiplexed, buffered and inserted to the data stream input from the  
demultiplexed HTDATA pin.  
The user has the ability to control which channels are to have signaling data from the HTSIG pin inserted into them  
on a per-channel basis via the THSCS1 through THSCS3 registers.  
8.5.4 T1 Transmit Per-Channel Idle Code Insertion  
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive directions.  
Twenty-four Transmit Idle Definition Registers (TIDR1-TIDR24) are provided to set the 8-bit idle code for each  
channel. The Transmit Channel Idle Code Enable registers (TCICE1-3) are used to enable idle code replacement  
on a per channel basis.  
8.5.5 T1 Transmit Channel Mark Registers  
The Transmit Channel Mark Registers (TCMR1/TCMR2/TCMR3/TCMR4) control the mapping of channels to the  
transmit cell/packet interface and the TCHMRK pin. The TCHMRK signal is used internally to select which  
channels will be mapped to the transmit cell/packet interface. Externally, the signal can be used to multiplex TDM  
data into channels not used by the transmit cell/packet interface. When the appropriate bits are set to 1, the  
transmit cell/packet function is mapped to that channel and externally the TCHMRK pin is held high during the  
entire corresponding channel time. In T1 mode, only RCMR1 to RCMR3 and the LSB of RCMR4 are used.  
8.5.6 Fractional T1 Support (Gapped Clock Mode)  
The DS26556 can be programmed to output gapped clocks for selected channels in transmit path. When the  
TCHMRK pin is in the channel clock mode and gapped channel clock is enabled, a gated clock is output on the  
TCHMRK pin during selected channel times. The channel selection is controlled via the transmit-gapped-clock  
channel-select registers (TGCCS1-TGCCS4). If TCHMRK is in the channel clock mode, clock mode is enabled by  
the TGCLKEN bit (TESCR.6). Both 56kbps and 64kbps channel formats are supported as determined by  
TESCR.7. When 56kbps mode is selected, the clock corresponding to the Data/Control bit in the channel is  
omitted (only the seven most significant bits of the channel have clocks).  
8.5.7 T1 Transmit Bit Oriented Code (BOC) Controller  
The DS26556 contains a BOC generator on the transmit side and a BOC detector on the receive side. The BOC  
function is available only in T1 mode.  
Bits 0 through 5 in the TBOC register contain the BOC message to be transmitted. Setting SBOC = 1 (THC2.6)  
causes the transmit BOC controller to immediately begin inserting the BOC sequence into the FDL bit position. The  
transmit BOC controller automatically provides the abort sequence. BOC messages will be transmitted as long as  
SBOC is set. Note that the TFPT (TCR1.6) control bit must be set to 'zero' for the BOC message to overwrite F-bit  
information being sampled on TSER.  
8.5.8 T1 Transmit FDL  
When enabled with TCR2.7, the transmit section will shift out into the T1 data stream, either the FDL (in the ESF  
framing mode) or the Fs bits (in the D4 framing mode) contained in the Transmit FDL register (TFDL). When a new  
value is written to the TFDL, it will be multiplexed serially (LSB first) into the proper position in the outgoing T1 data  
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stream. After the full eight bits has been shifted out, the framer will signal the host microcontroller that the buffer is  
empty and that more data is needed by setting the TLS2.4 bit to a one. The INT will also toggle low if enabled via  
TIM2.4. The user has 2ms to update the TFDL with a new value. If the TFDL is not updated, the old value in the  
TFDL will be transmitted once again. Note that in this mode, no zero stuffing will be applied to the FDL data.  
In the D4 framing mode, the framer uses the TFDL register to insert the Fs framing pattern. To allow the device to  
properly insert the Fs framing pattern, the TFDL register must be programmed to 1Ch and the following bits must  
be programmed as shown: TCR2.7 = 0 (source Fs data from the TFDL register) TCR2.6 = 1 (allow the TFDL  
register to load on multiframe boundaries).  
8.5.9 Transmit SLC–96 Operation  
In a SLC–96 based transmission scheme, the standard Fs bit pattern is robbed to make room for a set of message  
fields. The SLC–96 multiframe is made up of six D4 superframes, hence it is 72 frames long. In the 72-frame  
SLC–96 multiframe, 36 of the framing bits are the normal Ft pattern and the other 36 bits are divided into alarm,  
maintenance, spoiler, and concentrator bits as well as 12 bits of the normal Fs pattern. Additional SLC-96  
information can be found in BellCore document TR–TSY–000008.  
To insert the SLC-96 message fields, the user has the option to either use the external TLINK pin or the use the  
onboard TFDL register. Use of the TLINK pin will require additional circuitry, and to enable this option the TCR2.7  
bit should be set to one. To insert the SLC-96 message using the TFDL register, the user should configure the  
DS26556 as shown below:  
TCR2.6 (TSLC96) = 1 Enable Transmit SLC-96  
TCR2.7 (TFDLS) = 0  
TCR3.2 (TFM) = 1  
TCR1.6 (TFPT) = 0  
Source FS bits via TFDL or SLC96 formatter  
D4 framing Mode  
Do not 'pass through' TSER F-bits.  
The DS26556 will automatically insert the 12-bit alignment pattern in the Fs bits for the SLC96 data link frame.  
Data from the TSLC1–TSLC3 will be inserted into the remaining Fs bit locations of the SLC96 multiframe. The  
status bit TSLC96 located at TLS1.4 will set to indicate that the SLC96 data link buffer has been transmitted and  
that the user should write new message data into TSLC1–TSLC3. The host will have 2.5ms after the assertion of  
TLS1.4 to write the registers TSLC1–TSLC3. If no new data is provided in these registers, the previous values will  
be retransmitted.  
8.5.10 Transmit HDLC Controller  
The HDLC controller can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 Mode) or the FDL (T1 Mode).  
The HDLC controller has a 64-byte FIFO buffer in both the transmit and receive paths. The user can select any  
specific bits within the time slot(s) to assign to the HDLC controller, as well as specific Sa bits (E1 Mode).  
The HDLC controller performs all the necessary overhead for generating and receiving Performance Report  
Messages (PRM) as described in ANSI T1.403 and the messages as described in AT&T TR54016. The HDLC  
controller automatically generates and detects flags, generates and checks the CRC check sum, generates and  
detects abort sequences, stuffs and de-stuffs zeros, and byte aligns to the data stream.  
8.5.10.1 Transmit HDLC FIFO Control  
Control of the transmit FIFO is accomplished via the Transmit HDLC FIFO Control (THFC). The FIFO Control  
register sets the watermarks for the receive FIFO.  
When the transmit FIFO empties below the low watermark, the TLWM bit in the appropriate HDLC status register  
will be set. TLWM is a real-time bit and remains set as long as the transmit FIFO’s write pointer is below the  
watermark. If enabled, this condition can also cause an interrupt via the INT pin.  
8.5.11 HDLC Transmit Example  
The HDLC status registers in the DS26556 allow for flexible software interface to meet the user’s preferences.  
When transmitting HDLC messages, the host can chose to be interrupt driven, or to poll to desired status registers,  
or a combination of polling and interrupt processes may be used. An example routine for using the DS26556 HDLC  
transmitter is given in Figure 8-13 HDLC Message Transmit Example.  
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Figure 8-13 HDLC Message Transmit Example  
Configure Transmit  
HDLC Controller  
(THC1,THC2,THBSE,THFC)  
Reset Transmit  
HDLC Controller  
(THC.5)  
Enable TLWM  
Interrupt and  
Verify TLWM Clear  
Set TEOM  
(THC1.2)  
Push Last Byte  
into Tx FIFO  
Read TFBA  
N = TFBA[6..0]  
Push Message Byte  
into Tx HDLC FIFO  
(THF)  
Enable TMEND  
Interrupt  
Loop N  
NO  
Last Byte of  
Message?  
YES  
TMEND  
Interrupt?  
A
NO  
YES  
Read TUDR  
Status Bit  
NO  
TLWM  
Interrupt?  
A
YES  
NO  
TUDR = 1  
YES  
A
No Action Required  
Work Another Process  
Disable TMEND Interrupt  
Prepare New  
Disable TMEND Interrupt  
Resend Message  
Message  
8.5.12 Programmable In-Band Loop-Code Generator  
The DS26556 can generate and detect a repeating bit pattern from one to eight bits or sixteen bits in length. This  
function is available only in T1 mode. To transmit a pattern, the user will load the pattern to be sent into the  
Transmit Code Definition registers (TCD1&TCD2) and select the proper length of the pattern by setting the TC0  
and TC1 bits in Transmit Control Register 4 (TCR4). When generating a 1-, 2-, 4-, 8-, or 16-bit pattern both  
transmit code definition registers (TCD1&TCD2) must be filled with the proper code. Generation of a 3, 5, 6 and 7  
bit pattern only requires TCD1 to be filled. Once this is accomplished, the pattern will be transmitted as long as the  
TLOOP control bit (TCR3.0) is enabled. Normally (unless the transmit formatter is programmed to not insert the F-  
bit position) the framer will overwrite the repeating pattern once every 193 bits to allow the F-bit position to be sent.  
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As an example, to transmit the standard “loop-up” code for Channel Service Units (CSUs), which is a repeating  
pattern of ...10000100001..., set TCD1 = 80h, TC0=0, TC1=0, and TCR3.0 = 1.  
8.5.13 Interfacing the T1 Tx Formatter to the BERT  
Data from the BERT can be inserted into the DS26556 transmit formatter data stream. Either framed or unframed  
format can be transmitted, controlled by the TBFUS bit in the TBICR. Any signal DS0, combination of DS0s, or the  
entire bandwidth can be replaced with the BERT data as controlled by the TBCS registers.  
8.5.14 T1 Transmit Synchronizer  
When enabled, the DS26556 transmitter has the ability to identify the D4 or ESF frame boundary within the  
incoming NRZ data stream at TSER. The TFM (TCR3.2) control bit determines whether the transmit synchronizer  
searches for the D4 or ESF multiframe. Additional control signals for the transmit synchronizer are located in the  
TSYNCC register. The Transmit Latched Status 3 (TLS3) register provides a latched status bit (LOFD) to indicate  
that a Loss-of-Frame synchronization has occurred, and a real-time bit (LOF) which is set high when the  
synchronizer is searching for frame/multiframe alignment. The LOFD bit can be enabled to cause an interrupt  
condition on INT.  
Note that when the transmit synchronizer is used, the TSYNC signal should be set as an output (TSIO = 1) and the  
recovered frame sync pulse will be output on this signal. The recovered multiframe sync pulse will be output if  
enabled with TIOCR.0 (TSM = 1).  
8.6 E1 Receive Framer Description and Operation  
Four fully independent DS1/E1 framers are included within the DS26556. Each framer can be individually  
programmed to accept AMI, HDB3 (E1), B8ZS (T1), or NRZ data. In E1 mode each framer supports FAS, CRC-4,  
and CAS frame formats, and detects/reports common alarms such as AIS, RAI, LOS, and LOF. Performance  
monitor counters are maintained for each port that reports bipolar/line code violations, CRC-4 errors, FAS errors,  
and E-bits.  
Each framer has an HDLC controller which can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 Mode) or  
the FDL (T1 Mode) and includes 64 byte FIFO buffers in both the transmit and receive paths.  
Host interface is simplified with status registers optimized for either interrupt driven or polled environments. In  
many cases, status bits are reported both real-time and latched on change-of-state with separate bits for each  
state change. Most latched bits can be mapped to generate an external interrupt on the INT pin.  
8.6.1 H.100 (CT Bus) Compatibility  
The H.100 (or CT Bus) is a synchronous, bit-serial, TDM transport bus operating at 8.192MHz. The H.100  
standard also allows compatibility modes to operate at 2.048MHz, 4.096MHz, or 8.192MHz. The control bit  
H100EN (RIOCR.5), when combined with HSSYNCINV allows the DS26556 to accept the CT-Bus compatible  
frame sync signal (/CT_FRAME) at the HSSYNC input. The following rules apply to the H100EN control bit:  
1) The H100EN bit controls the sampling point for the HSSYNC only.  
2) The H100EN bit in RIOCR controls HSSYNC.  
3) The H100EN bit does not invert the expected signal; HSSYNCINV (TIOCR) must be set ‘high’ to invert the  
inbound sync signals.  
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Figure 8-14 HSSYNC Input in H.100 (CT Bus) Mode  
HSSYNC1  
HSSYNC2  
HSYSCLK  
HTDATA,  
HRDATA  
Bit 8  
Bit 1  
Bit 2  
3
tbc  
NOTE 1: HSSYNC IN NORMAL OPERATION.  
NOTE 2: HSSYNC WITH H100EN = 1 and HSSYNCINV = 1.  
NOTE 3: tbc (BIT-CELL TIME) = 122ns (typ). tbc = 244ns or 488ns ALSO ACCEPTABLE.  
8.6.2 E1 Error Count Registers  
The DS26556 contains four counters that are used to accumulate line coding errors, path errors, and  
synchronization errors. Counter update options include one-second boundaries, 42ms (T1 mode only), 62.5ms (E1  
mode only), or manually. See Error Counter Configuration Register (ERCNT). When updated automatically, the  
user can use the interrupt from the timer to determine when to read these registers. All four counters will saturate  
at their respective maximum counts and they will not rollover. The Line-Code Violation Count Register has the  
potential to saturate, but the bit error would have to exceed 10E-2 before this would occur. All other counters will  
roll over.  
Several options are available for latching the performance counters:  
1) Each framer’s counters are latched independently based on independent one-second interval timers.  
2) Each framer’s counters are latched independently based on independent 62.5ms interval timers.  
3) Each framer’s counters are latched independently with a low to high transition on the respective MECU control  
bit.  
4) Counters from selected framers are latched synchronously at the one-second interval supplied by framer_#1.  
5) Counters from selected framers are synchronously latched manually with the Global Counter Latch Enable  
(GCLE) bit in GCR1.  
The following table shows configuration bit settings in the ERCNT register for each of the 5 modes mentioned  
above:  
Control Bit  
EAMS  
ECUS  
MECU  
MCUS  
1SECS  
Mode 1  
Mode 2  
Mode 3  
Mode 4  
Mode 5  
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
X
0 to 1  
0
0
8.6.2.1 E1 Line Code Violation Count Register (LCVCR)  
Either bipolar violations or code violations can be counted. Bipolar violations are defined as consecutive marks of  
the same polarity. In this mode, if the HDB3 mode is set for the receive side; HDB3 codewords are not counted as  
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BPVs. If ERCNT.0 is set, then the LVC counts code violations as defined in ITU O.161. Code violations are defined  
as consecutive bipolar violations of the same polarity. In most applications, the framer should be programmed to  
count BPVs when receiving AMI code and to count CVs when receiving HDB3 code. This counter increments at all  
times and is not disabled by loss of sync conditions. The counter saturates at 65,535 and will not rollover. The bit  
error rate on an E1 line would have to be greater than 10** - 2 before the VCR would saturate. See Table 8-2.  
Table 8-2 E1 Line Code Violation Counting Options  
E1 CODE VIOLATION SELECT  
WHAT IS COUNTED IN THE LCVCRs  
(ERCNT.0)  
0
1
BPVs  
CVs  
8.6.3 DS0 Monitoring Function  
The DS26556 has the ability to monitor one DS0 64kbps channel in the transmit direction and one DS0 channel in  
the receive direction at the same time. In the receive direction, the RCM0 to RCM4 bits in the RDS0SEL register  
need to be properly set and the DS0 channel pointed to by the RCM0 to RCM4 bits will appear in the Receive DS0  
(RDS0M) register. The RCM0 to RCM4 bits should be programmed with the decimal decode of the appropriate E1  
channel. E1 channels 1 through 32 map to register values 0 through 31. For example, if DS0 channel 15 in the  
receive direction needed to be monitored, then the following values would be programmed into RDS0SEL:  
RCM4 = 0  
RCM3 = 1  
RCM2 = 1  
RCM1 = 1  
RCM0 = 0  
8.6.4 E1 Receive Signaling Operation  
Signaling data is sampled in the receive data stream and copied into the receive signaling registers, RS1 through  
RS16. The signaling information in these registers is always updated on multiframe boundaries. This function is  
always enabled. NOTE: The receive framer does not normally remove TS16 signaling from the data stream.  
Signaling information is present in the data stream at the RSER pin unless the receive framer has been  
programmed to over-lay TS16 with idle codes or to force signaling bit positions to a “one” state. The  
signaling data in data stream at the HRDATA pin can be re-aligned to a users multiframe reference. See  
Signaling Reinsertion below.  
CAS signaling (time slot 16) is sampled in the receive data stream and copied into the receive-signaling registers,  
RS1 through RS16. The signaling information in these registers is always updated on CAS multiframe boundaries.  
This function is referred to as “Software Based Signaling” and is always enabled. Time slot 16 is always sampled  
and loaded into the signaling registers even though CAS signaling data may not be present.  
When the high speed multiplexed TDM bus is utilized, a TDM signaling stream is available at the HRSIG pin. This  
is referred to as “Hardware Based Signaling”.  
8.6.4.1 Change Of State  
In order to avoid constantly monitoring of the receive signaling registers the DS26556 can be programmed to alert  
the host when any specific channel or channels undergo a change of their signaling state. RSCSE1 through  
RSCSE4 for E1 are used to select which channels can cause a change of state indication. The change of state is  
indicated in Latched Status Register 4 (RLS4.3). If signaling integration is enabled then the new signaling state  
must be constant for 3 multiframes before a change of state indication is indicated. The user can enable the INT  
pin to toggle low upon detection of a change in signaling by setting the appropriate interrupt mask bit RIM4.3. The  
signaling integration mode is global and cannot be enabled on a channel-by-channel basis.  
The user can identity which channels have undergone a signaling change of state by reading the Receive  
Signaling Status (RSS1 through RSS4) registers. The information from these registers tells the user which RSx  
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register to read for the new signaling data. All changes are indicated in the RSS1–RSS4 registers regardless of  
the RSCSE1–RSCSE4 registers.  
8.6.4.2 Hardware-Based Receive Signaling  
HRSIG is a signaling PCM stream output on a channel-by-channel basis from the signaling buffer. The ABCD  
signaling bits are output on HRSIG in the lower nibble of each channel. HRSIG is updated once per CAS  
multiframe (2ms) unless a freeze is in effect. TS16 signaling data is still present in the original data stream at  
RSER. A signaling buffer provides signaling data to the HRSIG pin and also allows signaling data to be re-inserted  
into the original data stream in a different alignment that is determined by a multiframe signal from the RSYNC pin.  
When signaling integration is enabled the signaling data at RSIG is automatically debounced. Signaling must be  
constant for three multiframes before being up-dated at RSIG. Signaling debounce is enabled on a global basis.  
8.6.5 Fractional E1 Support (Gapped Clock Mode)  
The DS26556 can be programmed to output gapped clocks for selected channels in receive path. When the  
RCHMRK pin is in the channel clock mode and gapped channel clock is enabled, a gated clock is output on the  
RCHMRK pin during selected channel times. The channel selection is controlled via the receive-gapped-clock  
channel-select registers (RGCCS1-RGCCS4). If RCHMRK is in the channel clock mode, clock mode is enabled by  
the RGCLKEN bit (RESCR.6). Both 56kbps and 64kbps channel formats are supported as determined by  
RESCR.7. When 56kbps mode is selected, the clock corresponding to the Data/Control bit in the channel is  
omitted (only the seven most significant bits of the channel have clocks).  
8.6.6 Additional Sa-Bit and Si-Bit Receive Operation (E1 Mode)  
When operated in the E1 mode the DS26556 receiver provides extended access to both the Sa and the Si bits.  
The RAF and RNAF registers will always report the data as it received in the Sa and Si bit locations. The RAF and  
RNAF registers are updated on align frame boundaries. The setting of the Receive Align Frame bit in Latched  
Status Register 2 (RLS2.0) will indicate that the contents of the RAF and RNAF have been updated. The host can  
use the RLS2.0 bit to know when to read the RAF and RNAF registers. The host has 250μs to retrieve the data  
before it is lost.  
Also there are eight registers (RsiAF, RSiNAF, RRA, Rsa4 to Rsa8) that report the Si and Sa bits as they are  
received. These registers are updated with the setting of the Receive CRC4 Multiframe bit in Latched Status  
Register 2 (RLS2.1). The host can use the RLS2.1 bit to know when to read these registers. The user has 2ms to  
retrieve the data before it is lost. See the register descriptions below for additional information.  
8.6.7 HDLC Overhead Control Receive Example  
The HDLC status registers in the receive framer allow for flexible software interface to meet the user’s preferences.  
When receiving HDLC messages, the host can chose to be interrupt driven, or to poll to desired status registers, or  
a combination of polling and interrupt processes may be used. An example routine for using the DS26556 HDLC  
receiver is given in Figure 8-15.  
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Figure 8-15 Receive HDLC Example  
Configure Receive  
HDLC Controller  
(RHC, RHBSE, RHFC)  
Reset Receive  
HDLC Controller  
(RHC.6)  
Start New  
Message Buffer  
Enable Interrupts  
RPE and RHWM  
No Action Required  
Work Another Process  
NO  
Interrupt?  
YES  
Read Register  
RHPBA  
Read N Bytes From  
Rx HDLC FIFO (RHF)  
N = RHPBA[5..0]  
NO  
MS = 0?  
(MS = RHPBA[7])  
YES  
Read RRTS5 for  
Packet Status (PS2..0)  
Take appropriate action  
8.6.8 Interfacing the E1 Rx Framer to the BERT  
The Receive BERT receives data from the framer when the receive BERT is enabled. Any single DS0 or  
combination of DS0s can be extracted from the data stream up to the entire T1 payload as controlled by the RBCS  
registers.  
Details concerning the on-chip BERT can be found in Section 13.  
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8.6.9 E1 Transmit Formatter Description and Operation  
Four fully independent DS1/E1 transmit formatters are included within the DS26556. Each port can be individually  
programmed to transmit AMI, HDB3 (E1), or NRZ data. In E1 mode, each formatter supports FAS, CRC-4, and  
CAS frame formats, transmits common alarms such as AIS and RAI.  
Each transmitter has an HDLC controllers which can be mapped into a single time slot, or Sa4 to Sa8 bits (E1  
mode) or the FDL (T1 mode) and has 64-byte FIFO buffers in both the transmit and receive paths.  
Host interface is simplified with status registers optimized for either interrupt driven or polled environments. In  
many cases, status bits are reported both real-time and latched on change-of-state with separate bits for each  
state change. Most latched bits can be mapped to generate an external interrupt on the INT pin.  
Additional details concerning the operation of the E1 formatter are included within the register descriptions within  
this section.  
8.6.10 Automatic Alarm Generation  
The device can be programmed to automatically transmit AIS or Remote Alarm. When automatic AIS generation is  
enabled (TCR2.6 = 1), the device monitors the receive side framer to determine if any of the following conditions  
are present: loss of receive frame synchronization, AIS alarm (all one’s) reception, or loss of receive carrier (or  
signal). If any one (or more) of the above conditions is present, then the framer forces an AIS.  
When automatic RAI generation is enabled (TCR2.5 = 1), the framer monitors the receive side to determine if any  
of the following conditions are present: loss of receive frame synchronization, AIS alarm (all ones) reception, or  
loss of receive carrier (or signal) or if CRC4 multiframe synchronization cannot be found within 128ms of FAS  
synchronization (if CRC4 is enabled). If any one (or more) of the above conditions is present, then the framer will  
transmit a RAI alarm. RAI generation conforms to ETS 300 011 specifications and a constant Remote Alarm will  
be transmitted if the DS26556 cannot find CRC4 multiframe synchronization within 400ms as per G.706.  
Note: It is an illegal state to have both automatic AIS generation and automatic Remote Alarm generation enabled  
at the same time.  
8.6.11 G.706 Intermediate CRC-4 Updating (E1 Mode Only)  
When a port is operating in a full or partial TDM mode and the E1 CRC framing structure is present in the data  
stream at TSER, the transmit framer can recalculate the CRC4 check-sum. The recalculation will take into account  
any changes made to the Sa bits by the host without disturbing any bit error information contained in CRC4  
structure present at TSER.  
The E1 transmit framer can implement the G.706 CRC-4 recalculation at intermediate path points. When this  
mode is enabled, the data stream presented at TSER will already have the FAS/NFAS, CRC multiframe alignment  
word and CRC-4 checksum in time slot 0. The user can modify the Sa bit positions and this change in data content  
will be used to modify the CRC-4 checksum. This modification however will not corrupt any error information the  
original CRC-4 checksum may contain. In this mode of operation, TSYNC must be configured to multiframe mode.  
The data at TSER must be aligned to the TSYNC signal. If TSYNC is an input then the user must assert TSYNC  
aligned at the beginning of the multiframe relative to TSER. If TSYNC is an output, the user must multiframe-align  
the data presented to TSER. This mode is enabled with the TCR3.0 control bit (CRC4R).  
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Figure 8-16 CRC Update Flow Diagram  
TPOSO/TNEGO  
INSERT  
NEW CRC-4  
CODE  
EXTRACT  
OLD CRC-4  
CODE  
TSER  
CRC-4  
CALCULATOR  
XOR  
MODIFY  
Sa BIT  
+
POSITIONS  
NEW Sa BIT  
DATA  
8.6.12 E1 Transmit DS0 Monitoring Function  
The DS26556 can monitor one DS0 64kbps channel in the transmit direction and one DS0 channel in the receive  
direction at the same time. In the transmit direction the user will determine which channel is to be monitored by  
properly setting the TCM0 to TCM4 bits in the TDS0SELregister. In the receive direction, the RCM0 to RCM4 bits  
in the RDS0SEL register need to be properly set. The DS0 channel pointed to by the TCM0 to TCM4 bits will  
appear in the Transmit DS0 Monitor (TDS0M) register and the DS0 channel pointed to by the RCM0 to RCM4 bits  
will appear in the Receive DS0 (RDS0M) register. The TCM4 to TCM0 and RCM4 to RCM0 bits should be  
programmed with the decimal decode of the appropriate T1or E1 channel. T1 channels 1 through 24 map to  
register values 0 through 23. E1 channels 1 through 32 map to register values 0 through 31. For example, if DS0  
channel 6 in the transmit direction and DS0 channel 15 in the receive direction needed to be monitored, then the  
following values would be programmed into TDS0SEL and RDS0SEL:  
TCM4 = 0  
TCM3 = 0  
TCM2 = 1  
TCM1 = 0  
TCM0 = 1  
RCM4 = 0  
RCM3 = 1  
RCM2 = 1  
RCM1 = 1  
RCM0 = 0  
8.6.13 E1 Transmit Signaling Operation  
There are two methods of providing transmit signaling data—processor-based (i.e., software-based) or hardware-  
based. Processor-based refers to access through the transmit signaling registers, TS1 through TS16, while  
hardware-based refers to using the HTSIG pins. Hardware based signaling is available only when the port is  
configured in the multiplexed bus mode utilizing the high speed TDM port. Both methods can be used  
simultaneously. Note: Signaling data may already be imbedded in the transmit data streams at the TSER or  
HTDATA pins. In this case the two methods mentioned above may be used to update any or all channels.  
8.6.13.1 Software Signaling  
Signaling data is loaded into the Transmit Signaling registers (TS1–TS16) via the host interface. On multiframe  
boundaries, the contents of these registers are loaded into a shift register for placement in the appropriate bit  
position in the outgoing data stream. The user can utilize the Transmit Multiframe Interrupt in Latched Status  
Register 1 (TLS1.2) to know when to update the signaling bits. The user need not update any transmit signaling  
register for which there is no change of state for that register.  
Each Transmit Signaling Register contains the TS16 CAS signaling (E1) for one time slot that will be inserted into  
the outgoing stream if enabled to do so via TCR1.6. Signaling data can be sourced from the TS registers on a per-  
channel basis by utilizing the Software Signaling Insertion Enable registers, SSIE1 through SSIE4.  
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TS16 carries the signaling information. This information can be in either CCS (Common Channel Signaling) or  
CAS (Channel Associated Signaling) format. The 32 time slots are referenced by two different channel number  
schemes in E1. In “Channel” numbering, TS0 through TS31 are labeled channels 1 through 32. In “Phone  
Channel” numbering TS1 through TS15 are labeled channel 1 through channel 15 and TS17 through TS31 are  
labeled channel 15 through channel 30.  
8.6.13.2 Hardware Signaling  
Hardware signaling is only available when the port is configured to use the high speed TDM bus. Note: the  
cell/packet interface is unavailable to this port in this mode. In hardware mode, signaling data is input via the  
HTSIG pin. This signaling PCM stream is demultiplexed, buffered and inserted to the data stream input from the  
demultiplexed HTDATA pin.  
The user has the ability to control which channels are to have signaling data from the HTSIG pin inserted into them  
on a per-channel basis via the THSCS1 through THSCS4 registers.  
Figure 8-17 Time Slot Numbering Schemes  
0
1
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32  
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  
TS  
2
1
3
2
4
3
5
4
6
5
7
6
8
7
Channel  
8
Phone  
Channel  
8.6.14 Fractional E1 Support (Gapped Clock Mode)  
The DS26556 can be programmed to output gapped clocks for selected channels in transmit path. When the  
TCHMRK pin is in the channel clock mode and gapped channel clock is enabled, a gated clock is output on the  
TCHMRK pin during selected channel times. The channel selection is controlled via the transmit-gapped-clock  
channel-select registers (TGCCS1-TGCCS4). If TCHMRK is in the channel clock mode clock mode is enabled by  
the TGCLKEN bit (TESCR.6). Both 56kbps and 64kbps channel formats are supported as determined by  
TESCR.7. When 56kbps mode is selected, the clock corresponding to the Data/Control bit in the channel is  
omitted (only the seven most significant bits of the channel have clocks).  
8.6.15 Additional (Sa) and International (Si) Bit Operation (E1 Mode)  
On the transmit side, data is sampled from the TAF and TNAF registers with the setting of the Transmit Align  
Frame bit in Transmit Status Register 1 (TLS1.3). The host can use the TLS1.3 bit to know when to update the  
TAF and TNAF registers. It has 250μs to update the data or else the old data will be retransmitted. NOTE: If the  
TAF an TNAF registers are only being used to source the align frame and non-align frame sync patterns  
then the host need only write once to these registers. Data in the Si bit position will be overwritten if either the  
framer is programmed: (1) to source the Si bits from the TSER pin, (2) in the CRC4 mode, or (3) have automatic E-  
bit insertion enabled.  
There is also a set of eight registers (TSiAF, TSiNAF, TRA, TSa4 to TSa8) that, via the Transmit Sa-Bit Control  
Register (TSaCR), can be programmed to insert both Si and Sa data. Data is sampled from these registers with  
the setting of the Transmit Multiframe bit in Status Register 1 (TLS1.3). The host can use the TLS1.3 bit to know  
when to update these registers. It has 2ms to update the data or else the old data will be retransmitted.  
8.6.16 E1 Transmit HDLC Controller  
Each framer port has an HDLC controller with 64-byte FIFOs.  
The HDLC controller can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 Mode) or the FDL (T1 mode).  
This block has 64-byte FIFO buffers in both the transmit and receive paths. The user can select any specific bits  
within the time slot(s) to assign to the HDLC controller, as well as specific Sa bits (E1 mode). The HDLC controllers  
automatically generate and detect flags, generate and check the CRC checksum, generate and detect abort  
sequences, stuff and destuff zeros, and byte align to the data stream.  
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8.6.17 E1 HDLC Transmit Example  
The HDLC status registers in the DS26556 allow for flexible software interface to meet the user’s preferences.  
When transmitting HDLC messages, the host can choose to be interrupt driven, or to poll to desired status  
registers, or a combination of polling and interrupt processes may be used.  
Figure 8-18 E1 HDLC Message Transmit Example  
Configure Transmit  
HDLC Controller  
(THC1,THC2,THBSE,THFC)  
Reset Transmit  
HDLC Controller  
(THC.5)  
Enable TLWM  
Set TEOM  
Interrupt and  
(THC1.2)  
Verify TLWM Clear  
Push Last Byte  
into Tx FIFO  
Read TFBA  
N = TFBA[6..0]  
Push Message Byte  
into Tx HDLC FIFO  
(THF)  
Enable TMEND  
Interrupt  
Loop N  
NO  
Last Byte of  
Message?  
YES  
TMEND  
Interrupt?  
A
NO  
YES  
Read TUDR  
Status Bit  
NO  
TLWM  
Interrupt?  
A
YES  
NO  
TUDR = 1  
YES  
A
No Action Required  
Work Another Process  
Disable TMEND Interrupt  
Prepare New  
Disable TMEND Interrupt  
Resend Message  
Message  
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8.6.18 Interfacing the E1 Transmitter to the BERT  
If the Transmit BERT is enabled, data will be inserted from the BERT into the transmit formatter. Any single DS0  
or combination of DS0s can be inserted into the data stream up to the entire T1 payload as controlled by the RBCS  
registers.  
Details concerning the BERT can be found in Section 13.  
8.6.19 E1 Transmit Synchronizer  
The DS26556 transmitter can identify the E1 frame boundary, as well as the CRC multiframe boundaries within the  
incoming NRZ data stream at TSER. Control signals for the transmit synchronizer are located in the TSYNCC  
register. The Transmit Synchronizer Status (TSYNCS) register provides a latched status bit (LOFD) to indicate that  
a loss-of-frame synchronization has occurred, and a real-time bit (LOF) which is set high when the synchronizer is  
searching for frame/multiframe alignment. The LOFD bit can be enabled to cause an interrupt condition on INT.  
Note that when the transmit synchronizer is used, the TSYNC signal should be set as an output (TSIO = 1) and the  
recovered frame sync pulse will be output on this signal. The recovered CRC4 multiframe sync pulse will be output  
if enabled with TIOCR.0 (TSM = 1).  
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9 LINE INTERFACE UNIT (LIU)  
The DS26556’s LIU provides the necessary transmit pulse shaping and receive signal processing for long-haul,  
short-haul, FCC CSU build-outs, and clock-synchronization applications. The transmitter and receiver have  
software selectable, internal termination for 75Ω, 100Ω, 110Ω, and 120Ω networks. The LIU block also contains a  
jitter attenuator that can be assigned to either the transmit or receive path, or disabled. Several loopbacks are  
provided for network and system side diagnostics. Each port’s LIU can be configured independently. The table  
below describes the registers involved in control and configuration of the LIUs.  
9.1 LIU Transmitter  
9.1.1 Pulse Shapes  
The transmit pulse shape is configured on a port-by-port basis. Pulse shapes are typically measured and  
compared to the appropriate pulse template at two locations in the network. For T1 long haul and FCC CSU  
applications the pulse is measured at the near-end NI (Network Interface). For T1 short haul applications the pulse  
is measured at the far-end NI. All E1 pulse shapes are measured at the near-end NI.  
9.1.2 Transmit Termination  
The LIU Transmit Impedance Selection Registers can be used to select an internal Transmit Terminating  
Impedance of 100Ω for T1, 110Ω for J1 Mode, 75Ω or 120Ω for E1 Mode, or no internal Termination for E1 or T1  
Mode. In this case the user has to provide the Line Terminating Network. The transmit pulse shape and terminating  
impedance is selected by the LTCR register.  
9.1.3 Power-Down and High-Z  
The DS26556 provides the ability to individually power-down the transmitters and/or place the transmit drivers into  
a High-Z state via register bits or device pins. This is useful for Protection Switching applications.  
The transmitters can be powered down by setting the TPDE bit in the LCCR2 register. Note that powering down  
the transmit LIU results in a High-Z state for the corresponding TTIP and TRING pins.  
9.1.4 Transmit All Ones  
When Transmit All Ones is invoked in the LIU block, continuous ones are transmitted using MCLK as the timing  
reference. Data and clock from the framer is ignored. Transmit all ones can be sent by setting a bit in the LCCR2  
register. Also transmit all ones will be are sent if the corresponding receiver goes into LOS state and the ATOS bit  
is set in the LCCR2 register.  
9.1.5 Driver Fail Monitor  
The transmit drivers have a monitor that will detect short circuit and open-circuit conditions at the TTIP and TRING  
pins. The drive current will be limited if a short circuit is detected. The status registers can be used to alert the user  
to an open circuit or short circuit condition.  
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Figure 9-1 T1/J1 Transmit Pulse Templates  
1.2  
1.1  
1.0  
N
O
0.9  
R
M
AL  
IZ  
ED  
A
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
M
PL  
IT  
UD  
E
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
T1.102/87, T1.403,  
CB 119 (Oct. 79), &  
I.431 Template  
-500  
-400  
-300  
-200  
-100  
0
100  
200  
300  
400  
500  
600  
700  
TIME (ns)  
DS1 Template (per ANSI T1.403 -  
DSX-1 Template (per ANSI T1.102 -  
MAXIMUM CURVE  
MINIMUM CURVE  
MAXIMUM CURVE  
MINIMUM CURVE  
UI  
Time  
Amp.  
UI  
Time  
Amp.  
UI  
Time  
Amp.  
UI  
Time  
Amp.  
-0.77  
-0.39  
-0.27  
-0.27  
-0.12  
0.00  
0.27  
0.35  
0.93  
1.16  
-500  
-255  
-175  
-175  
-75  
0.05  
0.05  
0.80  
1.15  
1.15  
1.05  
1.05  
-0.07  
0.05  
0.05  
-0.77  
-0.23  
-0.23  
-0.15  
0.00  
0.15  
0.23  
0.23  
0.46  
0.66  
0.93  
1.16  
-500  
-150  
-150  
-100  
0
100  
150  
150  
300  
430  
600  
750  
-0.05  
-0.05  
0.50  
0.95  
0.95  
0.90  
0.50  
-0.45  
-0.45  
-0.20  
-0.05  
-0.05  
-0.77  
-0.39  
-0.27  
-0.27  
-0.12  
0.00  
0.27  
0.34  
0.77  
1.16  
-500  
-255  
-175  
-175  
-75  
0.05  
0.05  
0.80  
1.20  
1.20  
1.05  
1.05  
-0.05  
0.05  
0.05  
-0.77  
-0.23  
-0.23  
-0.15  
0.00  
0.15  
0.23  
0.23  
0.46  
0.61  
0.93  
1.16  
-500  
-150  
-150  
-100  
0
100  
150  
150  
300  
430  
600  
750  
-0.05  
-0.05  
0.50  
0.95  
0.95  
0.90  
0.50  
-0.45  
-0.45  
-0.26  
-0.05  
-0.05  
0
0
175  
225  
600  
750  
175  
225  
600  
750  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 9-2 E1 Transmit Pulse Templates  
1.2  
1.1  
1.0  
0.9  
0.8  
0.7  
269ns  
G.703  
Template  
194ns  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
219ns  
-0.1  
-0.2  
-250  
-200  
-150  
-100  
-50  
0
50  
100  
150  
200  
250  
TIME (ns)  
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9.2 Receiver  
The receiver can function with “cable loss” signal attenuation of up to 36 dB for T1 Mode and 43 dB for E1 Mode.  
The receiver’s sensitivity can be limited to 12 dB for E1 mode or 15dB for T1 mode. For bridged monitor  
applications a resistive gain setting can be enabled to provide 14, 20, 26, and 32 dB of resistive gain.  
The peak detector and data slicer process the received signal. The output of the data slicer goes to a clock and  
data recovery circuit. A 2.048/1.544 PLL is internally multiplied by 16 via another internal PLL and fed to the clock  
recovery system that derives the E1 or T1 clock. The clock recovery system uses the clock from the PLL circuit to  
form a 16 times over sampler, which is used to recover the clock and data. This over sampling technique offers  
outstanding performance to meet jitter tolerance specifications.  
9.2.1 Receiver Monitor Mode  
Bridged monitor port isolation resistors typically cause resistive losses of 20dB(T1) and 32dB(E1). The receiver  
front end can be programmed for a fixed gain of 14dB, 20dB, 26dB, and 32dB to compensate for the monitor port’s  
loss. 12dB to 30dB of “cable loss” compensations is still available in monitor applications. See table as shown in  
LIU Receive Control Register (Section 9.2.1).  
Figure 9-3 Typical Monitor Operation  
PRIMARY  
T1/E1 LINE  
Rm  
T1/E1 TERMINATING  
DEVICE  
Rm  
X
F
M
R
DS26556  
Rt  
MONITOR  
PORT JACK  
SECONDARY T1/E1  
TERMINATING  
DEVICE  
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9.2.2 Peak Detector and Slicer  
The Slicer determines the polarity and presence of the received data. The output of the slicer is sent to the clock  
and data recovery circuitry for extraction of data and clock. The slicer has a built-in peak detector for determination  
of the slicing threshold.  
9.2.3 Clock and Data Recovery  
The resultant E1 or T1/J1 clock derived from the 2.048/1.544 PLL (JACLK in) is internally multiplied by 16 via  
another internal PLL and fed to the clock recovery system. The clock recovery system uses the clock from the PLL  
circuit to form a 16 times over sampler, which is used to recover the clock and data. This oversampling technique  
offers outstanding performance to meet jitter tolerance specifications shown in Figure 9-5.  
9.2.4  
Receive Level Indicator  
The signal strength at RTIP and RRING is reported in approximate 2.5dB increments via RSL3-RSL0 in the LRSL  
register. This feature is helpful when trouble-shooting line-performance problems. The DS26556 can initiate an  
interrupt whenever the input falls below a certain level through the input-level under-threshold indicator (SR1.7).  
Using the RLT0–RLT4 bits of the CCR4 register, the user can set a threshold in 2.5dB increments. The SR1.7 bit is  
set whenever the input level at RTIP and RRING falls below the threshold set by the value in RLT0–RLT4. The  
level must remain below the programmed threshold for approximately 50ms for this bit to be set. The accuracy of  
the receive level indication is ±1 LSB (2.5dB) from 25C to 85C and ±2 LSB’s (5dB) from –40C to 25C.  
9.2.5 Loss of Signal  
The DS26556 uses both the digital and analog loss detection method in compliance with the latest T1.231 for  
T1/J1 and ITU G.775 or ETSI 300 233 for E1 mode of operation.  
LOS is detected if the received signal level falls below a threshold for a certain duration. Alternatively, this can be  
termed as having received “zeros” for a certain duration. The signal level and timing duration are defined in  
accordance with the T1.231 or G.775 or ETSI 300 233 specifications.  
For short haul Mode, the loss detection thresholds are based on cable loss of 12/18 dB for both T1/J1 and E1  
Mode. The loss thresholds are selectable based on criteria defined in Table 9-1. For long-haul mode, the LOS  
Detection threshold is based on cable loss of 30/38 dB for T1/J1 and 30/45 dB for E1 Mode. Note there is no  
explicit bit called short-haul mode selection.  
The setting for the receiver sensitivity is through the LIU receive impedance and sensitivity monitor.  
The loss state is exited when the receiver detects a certain ones density at a higher signal level than the loss  
detection level. The loss detection signal level and loss reset signal level are defined with hysteresis to prevent the  
receiver from bouncing between “LOS” and “no LOS” states.  
The following table outlines the specifications governing the loss function:  
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Table 9-1 Loss Criteria T1.231, G.775 and ETSI 300 233 Specifications  
STANDARD  
ITU G.775  
No pulses are detected for No pulses are detected  
T1.231  
ETSI 300 233  
No pulses are detected  
for a duration of 2048 bit  
periods or 1 msec  
Loss reset criteria is not  
defined.  
Loss  
175 +/- 75 bits.  
for duration of 10 to 255  
bit periods.  
Detection  
Criteria  
Loss  
Loss is terminated if a  
The incoming signal has  
duration of 12.5% ones are transitions for duration of  
Reset  
detected over duration of  
175 +/- 75 bits.  
10 to 255 bit periods.  
Criteria  
Loss is not terminated if 8  
consecutive zeros are  
found if B8ZS encoding is  
used. If B8ZS is not used  
loss is not terminated if  
100 consecutive pulses  
are zero.  
9.2.5.1 ANSI T1.231 for T1 and J1 Modes  
For Short-Haul Mode, loss is detected if the received signal level is less than 15/21 dB for a duration of 192 bit  
periods. LOS is reset if the all of the following criteria are met:  
24 or more ones are detected in 192-bit period with a detection threshold of 12/18 dB measured at RTIP  
and RRING.  
During the 192 bits less than 100 consecutive zeros are detected.  
For Long-Haul Mode, loss is detected if the received signal level is less than 33/39 dB for a duration of 192 bit  
periods. LOS is reset if the all of the following criteria are met:  
24 or more ones are detected in 192-bit period with a detection threshold of 30/36 dB measured at RTIP  
and RRING.  
During the 192 bits less than 100 consecutive zeros are detected.  
9.2.5.2 ITU G.775 for E1 Modes  
For Short-Haul Mode, LOS is detected if the received signal level is less than 15/21 dB for a continuous duration of  
192 bit periods. LOS is reset if the receive signal level is greater than 12/18 dB for a duration of 192 bit periods.  
For Long-Haul Mode, LOS is detected if the received signal level is less than 33/46 dB for a continuous duration of  
192 bit periods. LOS is reset if the receive signal level is greater than 30/43.  
9.2.5.3 ETSI 200 233 for E1 Modes  
For short-haul mode, LOS is detected if the received signal level is less than 15/21 dB for a continuous duration of  
2048 (1 msec) bit periods. LOS is reset if the receive signal level is greater than 12/18 dB for a duration of 192 bit  
periods.  
For long-haul mode, LOS is detected if the received signal level is less than 33/46 dB for a continuous duration of  
192 bit periods. LOS is reset if the receive signal level is greater than 30/43 dB for a duration of 192 bit periods.  
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Figure 9-4 Jitter Tolerance  
1k  
DS2655  
TOLERANC  
100  
TR 62411 (DEC. 90)  
10  
1
ITU-T G.823  
0.1  
1
10  
100  
1k  
10k  
100k  
FREQUENCY (Hz)  
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9.3 Jitter Attenuator  
The DS26556’s jitter attenuator that can be set to a depth of either 32 or 128 bits via the JADS bit in the LIU  
Common Control Register (LCCR).  
The 128-bit mode is used in applications where large excursions of wander are expected. The 32-bit mode is used  
in delay sensitive applications. The characteristics of the attenuation are shown in Figure 9-5. The jitter attenuator  
can be placed in either the receive path or the transmit path or disabled by appropriately setting the JAPS1 and  
JAPS0 bits in the LIU Common Control Register (LCCR).  
In order for the jitter attenuator to operate properly, a 2.048 MHz or multiple thereof or 1.544 MHz clock or multiple  
thereof must be applied at MCLK. ITU specification G.703 requires an accuracy of +/-50 ppm for both T1/J1 and  
E1 applications. TR62411 and ANSI specs require an accuracy of +/- 32 ppm for T1/J1 interfaces. Onboard  
circuitry adjusts either the recovered clock from the clock/data recovery block or the clock applied at the TCLK pin  
to create a smooth jitter free clock, which is used to clock data out of the jitter attenuator FIFO. It is acceptable to  
provide a gapped/bursty clock at the TCLK pin if the jitter attenuator is placed on the transmit side. If the incoming  
jitter exceeds either 120 UIP-P (buffer depth is 128 bits) or 28 UIP-P (buffer depth is 32 bits), then the DS26556 will  
set the jitter attenuator limit trip (JALTSLS) bit in the LIU latched status Register (LLSR) when the FIFO is 8 bits  
from underflow or overflow. The FIFO pointer will be 8 bits or 120 bits. In T1/J1 Mode the Jitter Attenuator corner  
frequency is 3.75 Hz and in E1 Mode it is 0.6 Hz.  
Figure 9-5 Jitter Attenuation  
0dB  
ITU G.7XX  
TBR12  
Prohibited  
Area  
Prohibited Area  
-20dB  
-40dB  
-60dB  
E1  
T1  
TR 62411 (Dec. 90)  
Prohibited Area  
1
10  
100  
1K  
10K  
100K  
FREQUENCY (Hz)  
9.4 LIU Loopbacks  
The DS26556 provides three loopbacks in the LIU block: analog loopback (ALB), local loopback (LLB), and remote  
loopback (RLB). Remote loopback (RLB) and local loopback (LLB) may be enabled simultaneously. Additionally,  
the framer block provides framer loopback (FLB) discussed in the framer section of the datasheet.  
9.4.1 Analog Loopback  
TTIP and TRING are looped to RTIP and RRING. Externally, signals at RTIP and RRING are ignored.  
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9.4.2 Local Loopback  
Data from the transmit backplane interface is looped back to the receive backplane interface. Data form the  
transmit system backplane will continue to be transmitted as normal.  
9.4.3 Remote Loopback  
The inputs decoded from the Receive LIU are looped back to the Transmit LIU. The inputs from the Transmit  
Framer are ignored during a remote loopback.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
10 OVERALL REGISTER MAP  
Table 10-1 Overall Register Map  
Address  
Description  
0000 – 01FF  
0200 – 03FF  
0400 – 05FF  
0600 – 07FF  
0800 – 09FF  
0A00 – 0BFF  
0C00 – 0DFF  
0E00 – 0FFF  
1000 – 11FF  
1200 – 13FF  
1400 – 15FF  
1600 – 17FF  
1800 – 18FF  
1900 – 19FF  
1A00 - 1FFF  
Port 1 Framer  
Port 2 Framer  
Port 3 Framer  
Port 4 Framer  
Port 1 LIU  
Port 2 LIU  
Port 3 LIU  
Port 4 LIU  
Port 1 Cell/Packet Processor  
Port 2 Cell/Packet Processor  
Port 3 Cell/Packet Processor  
Port 4 Cell/Packet Processor  
Global Registers  
System Interface Registers  
Unused  
The address offset for each port:  
Port 1 – No Offset  
Port 2 – Port 1 Address + 0200 Hex  
Port 3 – Port 1 Address + 0400 Hex  
Port 4 – Port 1 Address + 0600 Hex  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Table 10-2 Per Port Register Map  
Address offset  
0000 – 00DF  
00E0 – 00EF  
00F0 – 00FF  
0100 – 01DF  
01E0 – 01FF  
0800 – 080F  
0810 – 09FF  
1000 – 103F  
1040 – 104F  
1050 – 107F  
1080 – 108F  
1090 – 10FF  
1100 – 111F  
1120 – 117F  
1180 – 118F  
1190 – 11FF  
1800 – 181F  
1820 – 18FF  
1900 – 190F  
1910 – 193F  
1940 – 194F  
1950 – 1FFF  
Description  
RX FRAMER  
BERT  
UNUSED  
TX FRAMER  
UNUSED  
LIU  
UNUSED  
RX CELL/PKT PROCESSOR  
POS/PHY GEN  
UNUSED  
RX FIFO  
UNUSED  
TX CELL/PKT PROCESSOR  
UNUSED  
TX FIFO  
UNUSED  
GLOBAL REGISTERS (not per port)  
UNUSED  
RX SYSTEM (not per port)  
UNUSED  
TX SYSTEM (not per port)  
UNUSED  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11 REGISTER MAPS AND DESCRIPTIONS  
11.1 Global Registers  
Table 11-1 Global Register Map  
ADDRESS  
NAME  
FUNCTION  
1800  
1801  
1802  
1803  
1804  
1805  
1806  
1807  
1808  
IDR  
GCR1  
GCR2  
GCR3  
GCR4  
GCR5  
GCCR  
GSRR  
GRTPFS  
GSR1  
GSR2  
GSR3  
GSR4  
GSRL4  
GIM1  
Device ID Register  
Global Control Register 1  
Global Control Register 2  
Global Control Register 3  
Global Control Register 4  
Global Control Register 5  
Global Clock Control Register  
Global Software Reset Register  
Global RCHMRK and TCHMRK Pin Function Select Register  
Global Status Register 1  
Global Status Register 2  
Global Status Register 3  
Global Status Register 4  
Global Status Register Latched 4  
Global Interrupt Mask Register 1  
Global Interrupt Mask Register 2  
Global Interrupt Mask Register 3  
Global Interrupt Mask Register Latched 4  
Unused. Must be set = 0 for proper operation.  
1809  
180A  
180B  
180C  
180D  
180E  
180F  
GIM2  
GIM3  
GIM4  
1810  
1811  
1812 – 18FF  
11.1.1 Global Control Registers  
Register Name:  
Register Description:  
Address (hex):  
IDR  
Device Identification Register  
1800  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
ID7  
0
ID6  
0
ID5  
0
ID4  
0
ID3  
0
ID2  
0
ID1  
0
ID0  
0
Bits 7 to 4 : Device ID (ID7 to ID4) The upper four bits of the IDR are used to display the DS26556 ID.  
Bits 3 to 0 : Chip Revision Bits (ID3 to ID0) The lower four bits of the IDR are used to display the die revision of  
the chip. IDO is the LSB of a decimal code that represents the chip revision.  
DEVICE  
ID (ID7 to ID4)  
DS26556  
0000  
100 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GCR1  
Global Control Register 1  
1801  
Bit #  
Name  
Default  
7
SIW1  
0
6
SIW0  
0
5
SIM1  
0
4
SIM0  
0
3
DIREN  
0
2
RST  
0
1
RSTDP  
0
0
GRST  
0
Bits 7 to 6 : System Interface Bus Width (SIW[1:0]) These bits configure the system bus width.  
00 = 8 bit  
01 = 16 bit  
Bits 5 to 4 : System Interface Mode1 & 0 (SIM[1:0]) These bits configure the system bus mode.  
00 = UTOPIA II  
01 = UTOPIA 3  
10 = POS-PHY II  
11 = POS-PHY 3  
Bit 3 : Direct Status Enable (DIREN) This bit selects between the direct status and polled status modes for  
UTOPIA and POS-PHY.  
0 = Polled status mode  
1 = Direct status mode  
Bit 2 : (RST) When this bit is set, all of the UTOPIA/POS-PHY internal data path and status and control registers  
on all ports will be reset to their default state. This bit must be set high for a minimum of 100ns.  
0 = Normal operation.  
1 = Force all internal registers to their default values  
Bit 1 : (RSTDP) When this bit is set, it will force all of the UTOPIA/POS-PHY internal data path registers in the to  
their default state. This bit must be set high for a minimum of 100ns.  
0 = Normal operation.  
1 = Force all framer data path registers to their default values.  
Bit 0 : Global Reset (GRST) When this bit is set, all of the internal data path and status and control registers of  
the DS26556, on all ports, will be reset to their default state. This bit must be set high for a minimum of 100ns.  
0 = Normal operation.  
1 = Force all internal registers to their default values.  
.
101 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GCR2  
Global Control Register 2  
1802  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
BPMU  
0
1
GPMU  
0
0
TMEI  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : BERT Performance Monitor Register Update (BPMU) This bit is used to update all of the performance  
monitor registers (BERT) configured to use this bit. The performance registers configured to use this signal will be  
updated when this bit is toggled low to high, and the counters will be reset. The bit should remain high until the  
performance register update status bit goes high, then it should be brought back low which clears the PMS status  
bit.  
Bit 1 : Global Performance Monitor Register Update (GPMU) This bit is used to update all of the performance  
monitor registers configured to use this bit. The performance registers configured to use this signal will be updated  
when this bit is toggled low to high with the latest count value, and the counters will be reset. The bit should remain  
high until the performance register update status bit goes high, then it should be brought back low which clears the  
PMS status bit.  
Bit 0 : Transmit Manual Error Insert (TMEI) This bit is used insert an error in all ports and error insertion logic  
configured for global error insertion. An error(s) is inserted at the next opportunity when this bit transitions from low  
to high.  
Register Name:  
Register Description:  
Address (hex):  
GCR3  
Global Control Register 3  
1803  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
UPBWE  
0
2
LIUBWE  
0
1
BTBWE  
0
0
FRBWE  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : UTOPIA/POS-PHY Bulk Write Enable (UPBWE) This bit enables the UTOPIA/POS-PHY bulk write mode.  
When this bit is set, a write to the register in the Cell/Packet interface of any port will write to the same register in  
all ports. Reading the registers of any port is not supported and will read back undefined data.  
Bit 2 : LIU Bulk Write Enable (LIUBWE) This bit enables the LIU bulk write mode. When this bit is set, a write to  
the register of any LIU will write to the same register in all the LIUs. Reading the registers of any LIU is not  
supported and will read back undefined data.  
Bit 1 : BERT Bulk Write Enable (BTBWE) This bit enables the BERT bulk write mode. When this bit is set, a write  
to the register of any BERT will write to the same register in all BERTs. Reading the registers of any BERT is not  
supported and will read back undefined data.  
Bit 0 : Framer Bulk Write Enable (FRBWE) This bit enables the framer bulk write mode. When this bit is set, a  
write to the register of any framer will write to the same register in all the framers. Reading the registers of any  
framer is not supported and will read back undefined data.  
102 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GCR4  
Global Control Register 4  
1804  
Bit #  
7
6
5
4
3
2
1
0
Name  
IBOMS1 IBOMS0  
BPCLK1  
BPCLK0 RF/RMSYN  
C
RLOF/ LOTC  
GCLE GIPI  
Default  
0
0
0
0
0
0
0
0
Bits 7 to 6 : Interleave Bus Operation Mode Select (IBOMS[1:0]) These bits determine the configuration of the  
IBO/Estore (interleaved bus/Elastic Store) multiplexer. These bits should be used in conjunction with the Rx and Tx  
IBO and ESTORE control registers within each of the framer units.  
IBOMS1  
IBOMS0  
Devices  
0
0
1
1
0
1
0
1
Disabled  
1
2
4
Bit 5 to 4 : Backplane Clock Select (BPCLK[1:0]) These bits determine the clock frequency output on the  
BPCLK pin.  
BPCLK1  
BPCLK0  
BP Freq  
2.048  
4.096  
8.192  
8.192  
0
0
1
1
0
1
0
1
Bit 3 : Receive Frame/Multiframe Sync Select (RF/RMSYNC) This bit controls the function of all four  
RFSYNC/RMSYNC pins.  
0 = RF/RMSYNC pins output RFSYNC.  
1 = RF/RMSYNC pins output RMSYNC.  
Bit 2 : Receive Loss of Frame / Loss of transmit clock (RLOF/LOTC) This bit controls the function of all four  
RLOF/LOTC pins.  
0 = RLOF/LOTC pins output RLOF(1-4) (Receive Loss of Frame)  
1 = RLOF/LOTC pins output LOTC(1-4) (Loss of Transmit clock)  
Bit 1 : Global Counter Latch Enable (GCLE) A low to high transition on this bit will, when enabled, latch the  
framer performance monitor counters. Each framer can be independently enabled to accept this input. Must be  
cleared and set again to perform another counter latch. The counters in the cell / packet interface block cannot be  
latched from this bit.  
Bit 0 : Global Interrupt Pin Inhibit (GIPI)  
0 = Normal Operation - interrupt pin (INT_B) will toggle low on an un-masked interrupt condition  
1 = Interrupt Inhibit - interrupt pin (INT_B) is forced high (inactive) when this bit is set.  
103 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GCR5  
Global Control Register 5  
1805  
Bit #  
Name  
Default  
7
IBEN4  
0
6
IBEN3  
0
5
IBEN2  
0
4
IBEN1  
0
3
-
0
2
SSEL1  
0
1
SSEL0  
0
0
SYNCIO  
0
Bit 7 : IBO Enable 4 (IBOEN4) This bit is used to determine if framer 4 is part of the IBO bus.  
0 = Framer 4 is not enabled for IBO.  
1 = Framer 4 is enabled for IBO.  
Bit 6 : IBO Enable 3 (IBOEN3) This bit is used to determine if framer 3 is part of the IBO bus.  
0 = Framer 3 is not enabled for IBO.  
1 = Framer 3 is enabled for IBO.  
Bit 5 : IBO Enable 2 (IBOEN2) This bit is used to determine if framer 2 is part of the IBO bus.  
0 = Framer2 is not enabled for IBO.  
1 = Framer2 is enabled for IBO.  
Bit 4 : IBO Enable 1 (IBOEN1) This bit is used to determine if framer1 is part of the IBO bus.  
0 = Framer 1 is not enabled for IBO.  
1 = Framer 1 is enabled for IBO.  
Bit 3 : Unused. Must be set = 0 for proper operation.  
Bits 2 to 1 : HSSYNC Select (HSEL[1:0]) When SYNCIO is low, these bits are used to determine which framer  
drives the sync pulse.  
HSEL1  
HSEL0  
Framer  
FR1  
FR2  
FR3  
FR4  
0
0
1
1
0
1
0
1
Bit 0 : HSSYNC I/O Select (HSSYNCIO)  
0 = HSSYNC is an output. One of the framers’ RSYNC signal (based on HSEL[1:0]) is used as the sync  
pulse for IBO mode.  
1 = HSSYNC is an input. External frame sync is used as the sync pulse for IBO mode.  
104 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GCCR  
Global Clock Control Register  
1806  
Bit #  
Name  
Default  
7
-
0
6
BPREF2  
0
5
BPREF1  
0
4
3
2
MFREQ  
0
1
MPS1  
0
0
MPS0  
0
BPREF0 BPFREQ  
0
0
Bit 7 : Unused. Must be set = 0 for proper operation.  
Bits 6 to 4 : Backplane Reference Clock Select (BPREF[2:0]) This is used to select the reference clock for  
BPCLK generation. The BPCLK can be generated from any of the LIU recovered clocks, external reference or  
derivatives of MCLK input.  
BPREFSEL[2:0]  
BP Ref Clock Select  
BPFREQ  
000  
000  
001  
001  
010  
010  
011  
011  
T1 LIU RCLK1  
E1 LIU RCLK1  
T1 LIU RCLK2  
E1 LIU RCLK2  
T1 LIU RCLK3  
E1 LIU RCLK3  
T1 LIU RCLK4  
E1 LIU RCLK4  
1
0
1
0
1
0
1
0
1.544MHz derived from MCLK. Designates REFCLK to be an output and  
outputs 1.544MHz.  
2.048MHz derived from MCLK. Designates REFCLK to be an output and  
outputs 2.048MHz  
External REFCLK. Designates REFCLK to be an input (either 1.544MHz  
or 2.048MHz)  
100  
101  
110  
1
0
1 or 0  
Bit 3 : Backplane Reference Frequency Select (BPFREQ) In conjunction with BPREF[2:0], this bit selects the  
Reference Clock frequency for the DS26556 Backplane.  
0 = Backplane Reference Clock (determined by BPREFSEL[2:0]) is 2.048MHz.  
1 = Backplane Reference Clock (determined by BPREFSEL[2:0]) is 1.544MHz  
Note that the setting of this bit should match the T1/E1 selection for the LIU whose recovered clock is being used  
to generate the Backplane clock.  
Bit 2 : MCLK Frequency Selection (MFREQ) This bit selects the external MCLK frequency for the DS26556.  
0 = MCLK input is 2.048MHz or a multiple thereof.  
1 = MCLK input is 1.544MHz or a multiple thereof.  
Each of the LIU Framers can be selected for T1/J1 or E1 operation.  
BitS 1 to 0 : Master Period Select (MPS[1:0]) In conjunction with the MFREQ bit, these bits select the external  
MCLK frequency for the DS26556.  
MPS1  
MPS0  
Frequency (MHz)  
1.544  
MFREQ  
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
1
1
1
0
0
0
0
3.088  
6.176  
12.352  
2.048  
4.096  
8.192  
16.384  
105 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GSRR  
Global Software Reset Register  
1807  
Bit #  
7
6
LRST3  
0
5
LRST2  
0
4
LRST1  
0
3
FBRST4  
0
2
1
0
Name  
Default  
LRST4  
0
FBRST3 FBRST2 FBRST1  
0
0
0
Bit 7 to 4 : LIU Software Resets for Ports 1-4 (LRST[4:1])  
0 = Normal Operation  
1 = Resets the LIU  
Bits 3 to 0 : Framer/BERT Software Resets for Ports 1-4 (FBRST[4:1])  
0 = Normal Operation  
1 = Resets the Framer/BERT  
Register Name:  
Register Description:  
Address (hex):  
GRTPFS  
Global RCHMRK and TCHMRK Pin Function Select Register  
1807  
Bit #  
7
6
P3TFS  
0
5
P2TFS  
0
4
P1TFS  
0
3
P4RFS  
0
2
P3RFS  
0
1
P2RFS  
0
0
Name  
Default  
P4TFS  
0
P1RFS  
0
Bit 7 : Port 4 TCHMRK Pin Function Select (P4TFS)  
0 = TCHMRK in cell/packet mapping mode.  
1 = TCHMRK in channel clock mode.  
Bit 6 : Port 3 TCHMRK Pin Function Select (P3TFS)  
0 = TCHMRK in cell/packet mapping mode.  
1 = TCHMRK in channel clock mode.  
Bit 5 : Port 2 TCHMRK Pin Function Select (P2TFS)  
0 = TCHMRK in cell/packet mapping mode.  
1 = TCHMRK in channel clock mode.  
Bit 4 : Port 1 TCHMRK Pin Function Select (P1TFS)  
0 = TCHMRK in cell/packet mapping mode.  
1 = TCHMRK in channel clock mode.  
Bit 3 : Port 4 RCHMRK Pin Function Select (P4RFS)  
0 = RCHMRK in cell/packet mapping mode.  
1 = RCHMRK in channel clock mode.  
Bit 2 : Port 3 RCHMRK Pin Function Select (P3RFS)  
0 = RCHMRK in cell/packet mapping mode.  
1 = RCHMRK in channel clock mode.  
Bit 1 : Port 2 RCHMRK Pin Function Select (P2RFS)  
0 = RCHMRK in cell/packet mapping mode.  
1 = RCHMRK in channel clock mode.  
Bit 0 : Port 1 RCHMRK Pin Function Select (P1RFS)  
0 = RCHMRK in cell/packet mapping mode.  
1 = RCHMRK in channel clock mode.  
106 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.1.2 Global Status Registers  
Register Name:  
Register Description:  
Address (hex):  
GSR1  
Global Status Register 1  
1809  
Bit #  
Name  
Default  
7
BIS4  
0
6
BIS3  
0
5
BIS2  
0
4
BIS1  
0
3
FIS4  
0
2
FIS3  
0
1
FIS2  
0
0
FIS1  
0
Bit 7 : BERT Interrupt Status 4 (BIS4)  
0 = Bert 4 has not issued an interrupt  
1 = Bert 4 has issued an interrupt  
Bit 6 : BERT Interrupt Status 3 (BIS3)  
0 = Bert 3 has not issued an interrupt  
1 = Bert 3 has issued an interrupt  
Bit 5 : BERT Interrupt Status 2 (BIS2)  
0 = Bert 2 has not issued an interrupt  
1 = Bert 2 has issued an interrupt  
Bit 4 : BERT Interrupt Status 1 (BIS1)  
0 = Bert 1 has not issued an interrupt  
1 = Bert 1 has issued an interrupt  
Bit 3 : Framer Interrupt Status 4 (FIS4)  
0 = Framer 4 has not issued an interrupt  
1 = Framer 4 has issued an interrupt  
Bit 2 : Framer Interrupt Status 3 (FIS3)  
0 = Framer 3 has not issued an interrupt  
1 = Framer 3 has issued an interrupt  
Bit 1 : Framer Interrupt Status 2 (FIS2)  
0 = Framer 2 has not issued an interrupt  
1 = Framer 2 has issued an interrupt  
Bit 0 : Framer Interrupt Status 1 (FIS1)  
0 = Framer 1 has not issued an interrupt  
1 = Framer 1 has issued an interrupt  
107 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GIMR1  
Global Interrupt Mask Register 1  
180E  
Bit #  
Name  
Default  
7
BIM4  
0
6
BIM3  
0
5
BIM2  
0
4
BIM1  
0
3
FIM4  
0
2
FIM3  
0
1
FIM2  
0
0
FIM1  
0
Bit 7 : BERT Interrupt Mask 4 (BIM4)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6 : BERT Interrupt Mask 3 (BIM3)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5 : BERT Interrupt Mask 2 (BIM2)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : BERT Interrupt Mask 1 (BIM1)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Framer Interrupt Mask 4 (FIM4)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Framer Interrupt Mask 3 (FIM3)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Framer Interrupt Mask 2 (FIM2)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Framer Interrupt Mask 1 (FIM1)  
0 = interrupt masked  
1 = interrupt enabled  
108 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GSR2  
Global Status Register 2  
180A  
Bit #  
Name  
Default  
7
UPIS4  
0
6
UPIS3  
0
5
UPIS2  
0
4
UPIS1  
0
3
LIS4  
0
2
LIS3  
0
1
LIS2  
0
0
LIS1  
0
Bit 7 : UTOPIA/POS-PHY Interrupt Status 4 (UPIS4)  
0 = UTOPIA/POS-PHY Port 4 has not issued an interrupt  
1 = UTOPIA/POS-PHY Port 4 has issued an interrupt  
Bit 6 : UTOPIA/POS-PHY Interrupt Status 3 (UPIS3)  
0 = UTOPIA/POS-PHY Port 3 has not issued an interrupt  
1 = UTOPIA/POS-PHY Port 3 has issued an interrupt  
Bit 5 : UTOPIA/POS-PHY Interrupt Status 2 (UPIS2)  
0 = UTOPIA/POS-PHY Port 2 has not issued an interrupt  
1 = UTOPIA/POS-PHY Port 2 has issued an interrupt  
Bit 4 : UTOPIA/POS-PHY Interrupt Status 1 (UPIS1)  
0 = UTOPIA/POS-PHY Port 1 has not issued an interrupt  
1 = UTOPIA/POS-PHY Port 1 has issued an interrupt  
Bit 3 : LIU Interrupt Status 4 (LIS4)  
0 = LIU 4 has not issued an interrupt  
1 = LIU 4 has issued an interrupt  
Bit 2 : LIU Interrupt Status 3 (LIS3)  
0 = LIU 3 has not issued an interrupt  
1 = LIU 3 has issued an interrupt  
Bit 1 : LIU Interrupt Status 2 (LIS2)  
0 = LIU 2 has not issued an interrupt  
1 = LIU 2 has issued an interrupt  
Bit 0 : LIU Interrupt Status 1 (LIS1)  
0 = LIU 1 has not issued an interrupt  
1 = LIU 1 has issued an interrupt  
109 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GIMR2  
Global Interrupt Mask Register 2  
180F  
Bit #  
Name  
Default  
7
UPIM4  
0
6
5
4
UPIM1  
0
3
LIM4  
0
2
LIM3  
0
1
LIM2  
0
0
LIM1  
0
UPIM3 UPIM2  
0
0
Bit 7 : UTOPIA/POS-PHY Interrupt Mask 4 (UPIM4)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6 : UTOPIA/POS-PHY Interrupt Mask 3 (UPIM3)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5 : UTOPIA/POS-PHY Interrupt Mask 2 (UPIM2)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : UTOPIA/POS-PHY Interrupt Mask 1 (UPIM1)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : LIU Interrupt Mask 4 (LIM4)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : LIU Interrupt Mask 3 (LIM3)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : LIU Interrupt Mask 2 (LIM2)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : LIU Interrupt Mask 1 (LIM1)  
0 = interrupt masked  
1 = interrupt enabled  
110 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GSR3  
Global Status Register 3  
180B  
Bit #  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
TSSR  
0
Name  
Default  
Bit 7 – 1: Unused.  
Bit 0 : Transmit System Interface Status Register Interrupt Status (TSSR) This bit is set when any of the  
latched status register bits in the transmit system interface of the POS/PHY block are set and enabled for interrupt.  
Register Name:  
Register Description:  
Address (hex):  
GIMR3  
Global Interrupt Mask Register 3  
1810  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
TSSR  
0
0
0
0
0
0
0
0
Bit 7 – 1: Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit System Interface Status Register Interrupt Mask (TSSR)  
0 = interrupt masked  
1 = interrupt enabled  
Register Name:  
Register Description:  
Address (hex):  
GSR4  
Global Status Register 4  
180C  
Bit #  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
0
GPMS  
0
Name  
BPMS  
Default  
0
Bit 7 – 2: Unused  
Bit 1 : BERT Performance Monitoring Update Status (BPMS) This bit is set when all of the port performance  
register update status bits (BERT PMS) are set. It is an AND of all the BERT port PMU status bits.  
Bit 0 : Global Performance Monitoring Update Status (GPMS) This bit is set when all of the port performance  
register update status bits (PSR:PMU), that are enabled for global update control (PCR2:PMUM=1), are set. It is  
an AND of all the globally enabled port PMU status bits. In global software update mode, the global update request  
bit (GCR:GPMU) should be held high until this status bit goes high.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
GSRL4  
Global Status Register Latched 4  
180D  
Bit #  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
BPMS  
0
0
GPMS  
0
Name  
Default  
Bit 7 – 2: Unused.  
Bit 1 : BERT Performance Monitoring Update Status (BPMS) This bit is set when all of the port performance  
register update status bits (BERT PMS) are set. It is an AND of all the BERT port PMU status bits.  
Bit 0 : Global Performance Monitoring Update Status (GPMS) This bit is set when all of the port performance  
register update status bits (PSR:PMU), that are enabled for global update control (PCR2:PMUM=1), are set. It is  
an AND of all the globally enabled port PMU status bits. In global software update mode, the global update request  
bit (GCR:GPMU) should be held high until this status bit goes high.  
Register Name:  
Register Description:  
Address (hex):  
GIMR4  
Global Interrupt Mask Register 4  
1811  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
BPMS  
0
0
GPMS  
0
0
0
0
0
0
0
Bit 7 – 2: Unused. Must be set = 0 for proper operation.  
Bit 1 : BERT Performance Monitoring Update Status (BPMS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Global Performance Monitoring Update Status (GPMS)  
0 = interrupt masked  
1 = interrupt enabled  
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11.2 Cell / Packet Register Descriptions  
The register descriptions are divided into separate register block sections. Bits that are underlined are read-only;  
all other bits are read-write. Configuration registers and bits can be written to and read from during a data path  
reset (LDRST bit = 0), however, all changes to these bits will be ignored during the data path reset. As a result, all  
bits requiring a 0 to 1 transition to initiate an action must have the transition occur after the data path reset has  
been removed.  
All counters stop counting at their maximum count. A counter register is updated by asserting (low to high  
transition) the associated performance monitoring update signal (xxPMU). During the counter register update  
process, the associated performance monitoring status signal (xxPMS) will be deasserted. The counter register  
update process consists of loading the counter register with the current count, resetting the counter, forcing the  
zero count status indication low for one clock cycle, and then asserting xxPMS. No events shall be missed during  
an update procedure.  
A latched bit is set when the associated event occurs, and remains set until it is cleared. Once cleared, a latched  
bit will not be set again until the associated event reoccurs (goes away and comes back). A latched on change bit  
is a latched bit that is set when the event occurs, and when it goes away. A latched status bit is cleared when the  
register is selected (register addressed and associated BSxx high), the appropriate byte enable (LBE or UBE) is  
high, a logic one is present on the corresponding DI[x], and the LSRCK signal goes high.  
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11.2.1 General Cell / Packet Registers  
Table 11-2 General Cell / Packet Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1040  
NAME  
FUNCTION  
-
Unused. Must be set = 0 for proper operation.  
1041  
CPC1  
CELL / PACKET Control 1  
1042  
CPC2  
CELL / PACKET Control 2  
1043  
1044  
1045  
-
-
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
CELL / PACKET Interrupt Status  
CPIS  
1046  
1047  
1048  
1049  
CPPMS  
CELL / PACKET Performance Monitor Status  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
CELL / PACKET Performance Monitor Interrupt Enable  
Unused. Must be set = 0 for proper operation.  
-
-
-
104A  
CPPMIE  
-
104B – 104F  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
CPC1  
CELL / PACKET Control 1  
1041, 1241, 1441, 1641  
Bit #  
Name  
Default  
7
RCDV8  
0
6
--  
0
5
4
3
PMUM  
0
2
PMU  
0
1
LDRST  
0
0
LRST  
0
PMCPE SYSLBK  
0
0
Bit 7 : Receive ATM Cell Delineation Verify 8 enable (RCDV8) This bit determines the number of good cells  
required for the ATM cell delineator state machine to transition from the #Verify# state to the #Update# state.  
0 = Six valid ATM cells are required (typical for framed cells)  
1 = Eight valid ATM cells are required (typical for unframed cells)  
Bit 6 : Reserved. Must be set to 0 for proper operation.  
Bit 5 : POS-PHY Mode Cell Processor Enable (PMCPE) This bit determines the associated transmit and receive  
port interface processing (cell/packet) to be performed in the POS-PHY mode. It is only active in POS-PHY mode.  
0 = Packet processing will be performed  
1 = Cell processing will be performed  
Bit 4 : System Loopback (SYSLBK) This signal determines if cells/packets for the associated port are looped  
back to the system interface. When SYSLBK is low, the incoming cells/packets from the transmit FIFO are passed  
on to transmit cell/packet processor. When SYSLBK is high, the incoming cells/packets from the transmit FIFO are  
looped back to the receive FIFO. The transmit cell/packet processor outputs idle cells/inter-frame fill. This is an  
asynchronous signal.  
Bit 3 : Performance Monitor Update Mode (PMUM) This bit selects the method of updating the performance  
monitor registers. The global updates are controlled by the GCR2[1] bit.  
0 = Port software update  
1 = Global update  
Bit 2 : Performance Monitor Register Update (PMU) This bit is used to update all of the performance monitor  
registers configured to use this bit when PCR1:PMUM=0. The performance registers configured to use this signal  
will be updated when this bit is toggled low to high with the latest count value, and the counters reset. The bit  
should remain high until the performance register update status bit (PSR:PMS) goes high, then it should be  
brought back low which clears the PMS status bit.  
Bit 1 : (LDRST) When this bit is set, it will force all of the internal data path registers clocked by RSCK and TSCK  
pins in the corresponding cell / packet interface port to their default state. This bit must be set high for a minimum  
of 100ns.  
0 = Normal operation.  
1 = Force all data path registers to their default values.  
Bit 0 : (LRST) When this bit is set, all of the internal data path and status and control registers in the cell / packet  
interface, associated with line, will be reset to their default state for that port. This bit must be set high for a  
minimum of 100ns.  
0 = Normal operation.  
1 = Force all internal registers to their default values.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
CPC2  
CELL / PACKET Control 2  
1042, 1242, 1442, 1642  
Bit #  
Name  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
TBYT RBYT  
Default  
0
0
Bit 1 : Transmit Byte Synchronous Mode (TBYT) This signal determines the transmit physical interface bit/byte  
synchronous mode. When TBYT is high, the transmit physical interface will operate in byte synchronous mode  
(also known as octet aligned). When TBYT is low, the transmit physical interface will operate in bit synchronous  
mode.  
Bit 0 : Receive Byte Synchronous Mode (RBYT) This signal determines the receive physical interface bit/byte  
synchronous mode. When RBYT is high, the receive physical interface will operate in byte synchronous mode  
(also known as octet aligned). When RBYT is low, the receive physical interface will operate in bit synchronous  
mode.  
11.2.2 Cell/Packet Status Registers  
Register Name:  
Register Description:  
Address (hex):  
CPIS  
CELL / PACKET Interrupt Status  
1045, 1245, 1445, 1645  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
SFSR  
0
1
CPSR  
0
0
PMS  
0
-
-
-
-
-
Bit 2 : System FIFO Status Register Interrupt Status (SFSR) This bit is set when any of the latched status  
register bits, that are enabled for interrupt, in either the transmit or receive FIFO block are set. The interrupt pin will  
be driven when this bit is set and the GCR4.GIPI is set to zero. (INTRF[x] || INTTF[x])  
Bit 1 : Cell/Packet Status Register Interrupt Status (CPSR) This bit is set when any of the latched status  
register bits, that are enabled for interrupt, in the active transmit or receive cell processor or packet processor block  
are set. The interrupt pin will be driven when this bit is set and the GCR4.GIPI is set to zero. (INTRCP[x] ||  
INTTCP[x])  
Bit 0 : Performance Monitoring Update Status (PMS) This bit indicates the status of all active performance  
monitoring register and counter update signals in this port. It is an #AND# of all update status bits and is not set  
until all performance registers are updated and the counters reset. In software update modes, the update request  
bit PCR:PMU should be held high until this status bit goes high.  
0 = The associated update request signal is low.  
1 = The requested performance register updates are all completed.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
CPPMS  
CELL / PACKET Performance Monitor Status  
1046, 1246, 1446, 1646  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
PMSL  
0
Bits 7 – 1 : Unused  
Bit 0 : Performance Monitoring Update Status Latched (PMSL) This bit will be set when the PISR:PMS status  
bit changes from low to high. The GSR2:UPIS[x] bit will be set when this bit is set and the PSRIE:PMSIE bit is set  
and INT pin will be driven low when GCR4.GIPI is also set to zero.  
Register Name:  
Register Description:  
Address (hex):  
CPPMIE  
CELL / PACKET Performance Monitor Interrupt Enable  
104A, 124A, 144A, 164A  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
PMSIE  
0
Bits 7 – 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Performance Monitoring Update Latched Status Interrupt Enable (PMSIE) The interrupt pin will be  
driven when this bit is set and the PSRL:PMSL bit is set and the bit in GCR4.GIPI is set to zero.  
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11.2.3 Transmit FIFO Registers  
Figure 11-1 Transmit FIFO Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1180  
NAME  
FUNCTION  
TFC  
Transmit FIFO Control Register  
1181  
1182  
-
Unused. Must be set = 0 for proper operation.  
Transmit FIFO Level Control Register 1  
TFLC1  
1183  
TFLC2  
Transmit FIFO Level Control Register 2  
1184  
1185  
1186  
1187  
TFPAC  
Transmit FIFO Port Address Control Register  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Transmit FIFO Status Register Latched  
-
-
-
1188  
TFSRL  
1189  
118A  
118B – 118F  
-
Unused. Must be set = 0 for proper operation.  
Transmit FIFO Status Register Interrupt Enable  
Unused. Must be set = 0 for proper operation.  
TFSRIE  
-
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TFC  
Transmit FIFO Control Register  
1180, 1380, 1580, 1780  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TFRST  
1
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit FIFO Reset (TFRST) – When 0, the Transmit FIFO will resume normal operations, however, data  
is discarded until a start of packet/cell is received after RAM power-up is completed. When 1, the Transmit FIFO is  
emptied, any transfer in progress is halted, the FIFO RAM is powered down, the associated TDXA is forced low,  
and all incoming data is discarded. If the port was selected when the reset was initiated, the port will be  
deselected, and must be reselected (TEN deasserted with address on TADR or TSX asserted with address on  
TDAT) before any transfer will occur.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TFLC1  
Transmit FIFO Level Control Register 1  
1182, 1382, 1582, 1782  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TFAF5  
0
4
TFAF4  
1
3
TFAF3  
0
2
TFAF2  
0
1
TFAF1  
0
0
TFAF0  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 0 : Transmit FIFO Almost Full Level (TFAF[5:0]) – In POS-PHY packet processing mode, these six bits  
indicate the maximum number of four byte groups that can be available in the Transmit FIFO for it to be considered  
"almost full". E.g., a value of 30 (1Eh) results in the FIFO being "almost full" when it has 120 (78h) bytes or less  
available. In cell processing mode, TFAE[5:2] are ignored, and TFAE[1:0] indicate the maximum number of cells  
that can be available in the Transmit FIFO for it to be considered "almost full".  
Register Name:  
Register Description:  
Address (hex):  
TFLC2  
Transmit FIFO Level Control Register 2  
1183, 1383, 1583, 1783  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TFAE5  
0
4
TFAE4  
1
3
TFAE3  
0
2
TFAE2  
0
1
TFAE1  
0
0
TFAE0  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Transmit FIFO Almost Empty Level (TFAE[5:0]) – In POS-PHY packet processing mode, these six bits  
indicate the maximum number of four byte groups that can be stored in the Transmit FIFO for it to be considered  
"almost empty". E.g., a value of 30 (1Eh) results in the FIFO being "almost empty" when it contains 120 (78h) bytes  
or less. In cell processing mode, these bits are ignored.  
Register Name:  
Register Description:  
Address (hex):  
TFPAC  
Transmit FIFO Port Address Control Register  
1184, 1384, 1584, 1784  
Bit #  
Name  
Default  
7
TPA7  
0
6
TPA6  
0
5
TPA5  
0
4
TPA4  
0
3
TPA3  
0
2
TPA2  
0
1
TPA1  
0
0
TPA0  
0
Bits 7 to 0 : Transmit FIFO System Port Address (TPA[7:0]) – These eight bits set the Transmit FIFO system  
interface port address used to poll the Transmit FIFO for fill status, and select it for data transfer. In Level II mode,  
bits TPA[7:5] are ignored, and if bits TPA[4:0] are set to a value of 1Fh, the port is disabled.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TFSRL  
Transmit FIFO Status Register Latched  
1188, 1388, 1588, 1788  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
TFATL  
0
3
TFSTL  
0
2
TFITL  
0
1
TFUL  
0
0
TFOL  
0
Bits 7 to 5 : Unused.  
Bit 4 : Transmit FIFO Aborted Transfer Latched (TFATL) – This bit is set when a transfer is aborted. An aborted  
transfer does not occur in UTOPIA mode. In POS-PHY mode, an aborted transfer occurs when a packet error (a  
transfer with TERR and TEOP asserted) occurs. An aborted transfer is stored in the transmit FIFO with an abort  
indication.  
Bit 3 : Transmit FIFO Short Transfer Latched (TFSTL) – This bit is set when a "short transfer" is received. In  
UTOPIA mode, a "short transfer" occurs when a start of cell (a transfer with TSOC asserted) occurs before the  
previous cell transfer has been completed. In POS-PHY mode, a "short transfer" occurs when a start of packet (a  
transfer with TSOP asserted) occurs after a previous start of packet, but before an end of packet (a transfer with  
TEOP asserted). In UTOPIA mode, the short transfer data is discarded. In POS-PHY mode, a short transfer is  
stored in the transmit FIFO with an abort indication.  
Bit 2 : Transmit FIFO Invalid Transfer Latched (TFITL) – This bit is set when an "invalid transfer" is initiated. In  
UTOPIA mode, an "invalid transfer" occurs when additional cell data is transferred after the last transfer of a cell  
and before a transfer with TSOC asserted. In POS-PHY mode, an "invalid transfer" occurs when packet data is  
transferred after an end of packet, but before a start of packet (this includes another end of packet transfer). The  
invalid transfer data is discarded.  
Bit 1 : Transmit FIFO Underflow Latched (TFUL) – This bit is set when a Transmit FIFO underflow condition  
occurs. An underflow condition results in a loss of data.  
Bit 0 : Transmit FIFO Overflow Latched (TFOL) – This bit is set when a Transmit FIFO overflow condition  
occurs. An overflow condition results in a loss of data.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TFSRIE  
Transmit FIFO Status Register Interrupt Enable  
118A, 138A, 158A, 178A  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
TFATIE  
0
3
TFSTIE  
0
2
TFITIE  
0
1
TFUIE  
0
0
TFOIE  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Transmit FIFO Aborted Transfer Interrupt Enable (TFATIE) – This bit enables an interrupt if the TFATL  
bit in the TFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 3 : Transmit FIFO Short Transfer Interrupt Enable (TFSTIE) – This bit enables an interrupt if the TFSTL bit  
in the TFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 2 : Transmit FIFO Invalid Transfer Interrupt Enable (TFITIE) – This bit enables an interrupt if the TFITL bit in  
the TFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 1 : Transmit FIFO Underflow Interrupt Enable (TFUIE) – This bit enables an interrupt if the TFUL bit in the  
TFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 0 : Transmit FIFO Overflow Interrupt Enable (TFOIE) – This bit enables an interrupt if the TFOL bit in the  
TFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
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11.2.4 Transmit Cell Processor Registers  
Table 11-3 Transmit Cell Processor Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1100  
NAME  
FUNCTION  
TCPC1  
TCPC2  
-
Transmit Cell Processor Control Register 1  
Transmit Cell Processor Control Register 2  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Transmit Errored Cell Control Register 1  
Transmit Errored Cell Control Register 2  
Transmit HEC Error Mask Control Register  
Unused. Must be set = 0 for proper operation.  
Transmit Header Pattern Control Register 1  
Transmit Header Pattern Control Register 2  
Transmit Header Pattern Control Register 3  
Transmit Header Pattern Control Register 4  
Transmit Fill Cell Payload Pattern Control Register  
Unused. Must be set = 0 for proper operation.  
Transmit Cell Processor Status Register  
Unused. Must be set = 0 for proper operation.  
Transmit Cell Processor Status Register Latched  
Unused. Must be set = 0 for proper operation.  
Transmit Cell Processor Status Register Interrupt Enable  
Unused. Must be set = 0 for proper operation.  
Transmit Cell Count Register 1  
Transmit Cell Count Register 2  
Transmit Cell Count Register 3  
Unused. Must be set = 0 for proper operation.  
1101  
1102  
1103  
1104  
1105  
1106  
1107  
1108  
1109  
110A  
110B  
110C  
110D  
110E  
110F  
1110  
-
TECC1  
TECC2  
THMRC  
-
THPC1  
THPC2  
THPC3  
THPC4  
TFPPC  
-
TCPSR  
-
TCPSRL  
-
TCPSRIE  
-
TCCR1  
TCCR2  
TCCR3  
-
1111  
1112  
1113  
1114  
1115  
1116  
1117-111F  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCPC1  
Transmit Cell Processor Control Register 1  
1100, 1300, 1500, 1700  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TFCH  
0
4
TFCP  
0
3
THSE  
0
2
TSD  
0
1
TBRE  
0
0
TCCE  
0
Bits 7& 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Transmit Fill Cell Header Type (TFCH) – When 0, an idle cell header (00 00 00 01h) will be used in fill  
cells. When 1, a programmable header will be used in fill cells. The setting of this bit does not affect the contents of  
the cell payload bytes.  
Bit 4 : Transmit Fill Cell Payload Type (TFCP) – When 0, an idle cell payload byte (6Ah) will be used in each  
payload byte fill cells. When 1, a programmable cell payload byte will be used in each payload byte fill cells. The  
setting of this bit does not affect the contents of the cell header bytes.  
Bit 3 : Transmit Cell Header Scrambling Enable (THSE) – When 0, only the cell payload will be scrambled.  
When 1, the entire data stream (cell header and payload) is scrambled. This bit is ignored if scrambling is disabled,  
or DSS scrambling is enabled. When clear channel is enabled, the entire data stream will be scrambled if  
scrambling is enabled.  
Bit 2 : Transmit Scrambling Disable (TSD) – When 0, scrambling is performed. When 1, scrambling is disabled.  
Bit 1 : Transmit Bit Reordering Enable (TBRE) – When 0, bit reordering is disabled (The first bit transmitted is  
from the MSB of the transmit FIFO byte TFD[7]). When 1, bit reordering is enabled (The first bit transmitted is from  
the LSB of the transmit FIFO byte TFD[0]).  
Bit 0 : Transmit Clear Channel Enable (TCCE) – When 0, cell processing is enabled. When 1, clear channel is  
enabled, and all cell processing functions except scrambling and bit reordering are disabled.  
Register Name:  
Register Description:  
Address (hex):  
TCPC2  
Transmit Cell Processor Control Register 2  
1101, 1301, 1501, 1701  
Bit #  
Name  
Default  
7
SPARE  
0
6
--  
0
5
--  
0
4
--  
0
3
TDSE  
0
2
TDHE  
0
1
THPE  
0
0
TCPAD  
0
Bit 7 : Spare Configuration Bit (SPARE) – This bit is a spare configuration bit reserved for future use. It can be  
written to and read from, however it does not effect the operation of the CELL / PACKET INTERFACE.  
Bits 6 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit DSS Scrambling Enable (TDSE) – When 0, self-synchronous scrambling is enabled. When 1,  
DSS scrambling is enabled. This bit is ignored if scrambling is disabled. Note: In byte synchronous and clear  
channel modes self-synchronous scrambling is enabled regardless of the setting of this bit.  
Bit 2 : Transmit DQDB HEC Processing Enable (TDHE) – When 0, the HEC is calculated over all four header  
bytes. When 1, only the last three header bytes are used for HEC calculation.  
Bit 1 : Transmit HEC Pass-through Enable (THPE) – When 0, the calculated HEC byte will overwrite the HEC  
byte in the cell. When 1, the HEC byte in the cell is passed through. Note: The calculated HEC is always inserted  
into cells that are received without a HEC byte.  
Bit 0 : Transmit HEC Coset Polynomial Addition Disable (TCPAD) – When 0, the HEC coset polynomial  
addition is performed prior to inserting the HEC byte. When 1, HEC coset polynomial addition is disabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TECC1  
Transmit Errored Cell Control Register 1  
1104, 1304, 1504, 1704  
Bit #  
Name  
Default  
7
TCEN7  
0
6
TCEN6  
0
5
TCEN5  
0
4
TCEN4  
0
3
TCEN3  
0
2
TCEN2  
0
1
TCEN1  
0
0
TCEN0  
0
Bits 7 to 0 : Transmit Errored Cell Insertion Number (TCEN[7:0]) – These eight bits indicate the total number of  
errored cells to be transmitted. A value of FFh results in continuous errored cell insertion at the specified rate.  
Register Name:  
Register Description:  
Address (hex):  
TECC2  
Transmit Errored Cell Control Register 2  
1105, 1305, 1505, 1705  
Bit #  
Name  
Default  
7
MEIMS  
0
6
TCER6  
0
5
TCER5  
0
4
TCER4  
0
3
TCER3  
0
2
TCER2  
0
1
TCER1  
0
0
TCER0  
0
Bit 7 : Manual Error Insert Mode Select (MEIMS) – When 0, the transmit manual error insertion signal (TMEI) will  
not cause errors to be inserted. When 1, TMEI will cause an error to be inserted when it transitions from a 0 to a 1.  
Note: Enabling TMEI does not disable error insertion using TCER[6:0] and TCEN[7:0].  
Bits 6 to 0 : Transmit Errored Cell Insertion Rate (TCER[6:0]) – These seven bits indicate the rate at which  
errored cells are to be output. One out of every x * 10y cells is to be an errored cell. TCER[4:1] is the value x, and  
TCER[6:4] is the value y which has a maximum value of 6. If TCER[4:1] has a value of 0h errored cell insertion is  
disabled. If TCER[6:4] has a value of 6xh or 7xh the errored cell rate will be x * 106. A TCER[6:0] value of 01h  
results in every cell being errored. A TCER[6:0] value of 0Fh results in every 15th cell being errored. A TCER[6:0]  
value of 11h results in every 10th cell being errored. Errored cell insertion starts when the TECC register is written  
to with a TCER[4:1] value that is non-zero. If the TECC register is written to during the middle of an errored cell  
insertion process, the current process is halted, and a new process will be started using the new values of  
TCER[6:0] and TCEN[7:0}. Errored cell insertion ends when TCEN[7:0] errored cells have been transmitted.  
125 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THMRC  
Transmit HEC Error Mask Control Register  
1106, 1306, 1506, 1706  
Bit #  
Name  
Default  
7
THEM7  
0
6
THEM6  
0
5
THEM5  
0
4
THEM4  
0
3
THEM3  
0
2
THEM2  
0
1
THEM1  
0
0
THEM0  
0
Bits 7 to 0 : Transmit HEC Error Mask (THEM[7:0]) – These eight bits indicate whether or not the associated  
HEC bit is inverted during cell error insertion. If THEM[x] is high, HEC bit x is corrupted during an errored cell. If  
THEM[x] is low, HEC bit x is passed uncorrupted during an errored cell. If THEM[7:0] is all zeros, error insertion is  
disabled. The table below indicates the type of error inserted by a specific mask value. Note: If a single bit error is  
inserted in the HEC, and the far-end has single bit error correction enabled, this will cause the indicated header bit  
to be corrupted.  
Value  
01h-02h  
05h-06h  
09h-0Ah  
0Eh  
Error Type  
HEC  
Bit  
Value  
03h  
Error Type  
Multi  
Bit  
-
Value  
04h  
Error Type  
HEC  
Bit  
Multi  
07h  
Single  
Single  
Multi  
32  
09  
08h  
HEC  
Multi  
0Bh  
0Ch-0Dh  
10h  
Multi  
Single  
Multi  
31  
0Fh  
HEC  
11h-14h  
17h-1Dh  
20h  
15h  
Single  
Single  
Multi  
24  
30  
16h  
Single  
Multi  
08  
Multi  
1Eh  
1Fh  
HEC  
21h-29h  
2Ch  
2Ah  
Single  
Multi  
23  
2Bh  
Multi  
Single  
Multi  
07  
2Dh-30h  
38h  
31h  
Single  
Multi  
01  
32h-37h  
40h  
Single  
Multi  
29  
39h-3Fh  
43h  
HEC  
41h-42h  
51h  
Single  
Multi  
11  
44h-50h  
54h  
Multi  
Single  
Multi  
13  
52h-53h  
57h  
Single  
Single  
Multi  
22  
06  
55h-56h  
59h-5Ah  
67h  
Single  
Single  
Multi  
20  
18  
58h  
Multi  
5Bh  
5Ch-66h  
6Bh  
Single  
Multi  
04  
68h-6Ah  
70h  
Single  
Multi  
16  
6Ch-6Fh  
80h  
Single  
Multi  
28  
71h-7Fh  
86h  
HEC  
81h-85h  
89h  
Single  
Multi  
10  
87h-88h  
9Bh  
Multi  
Single  
Multi  
25  
90h-9Ah  
A2h  
Single  
Multi  
02  
9Ch-A1h  
A8h  
Single  
Multi  
12  
A3h-A7h  
ABh  
Single  
Multi  
21  
A9h-AAh  
AEh  
Single  
Multi  
14  
ACh-ADh  
B0h  
Single  
Multi  
19  
AFh  
Single  
Multi  
05  
B1h-B5h  
C7h  
B6h  
Single  
Multi  
17  
B7h-C6h  
CEh  
Single  
Multi  
26  
C8h-CDh  
D6h  
Single  
Multi  
03  
CFh-D5h  
E0h  
Single  
Multi  
15  
D7h-DFh  
Single  
27  
E1h-FFh  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Transmit Programmable Header Pattern (THP[31:0]) – These thirty-two bits indicate the header bit pattern to be  
used in the header of fill cells when the TCPC register bit TFCH is set.  
Register Name:  
Register Description:  
Address (hex):  
THPC1  
Transmit Header Pattern Control Register 1  
1108, 1308, 1508, 1708  
Bit #  
Name  
Default  
7
THP7  
0
6
THP6  
0
5
THP5  
0
4
THP4  
0
3
THP3  
0
2
THP2  
0
1
THP1  
0
0
THP0  
0
Bits 7 to 0 : Transmit Programmable Header Pattern (THP[7:0])  
Register Name:  
Register Description:  
Address (hex):  
THPC2  
Transmit Header Pattern Control Register 2  
1109, 1309, 1509, 1709  
Bit #  
Name  
Default  
7
THP15  
0
6
THP14  
0
5
THP13  
0
4
THP12  
0
3
THP11  
0
2
THP10  
0
1
THP9  
0
0
THP8  
0
Bits 7 to 0 : Transmit Programmable Header Pattern (THP[15:8])  
Register Name:  
Register Description:  
Address (hex):  
THPC3  
Transmit Header Pattern Control Register 3  
110A, 130A, 150A, 170A  
Bit #  
Name  
Default  
7
THP23  
0
6
THP22  
0
5
THP21  
0
4
THP20  
0
3
THP19  
0
2
THP18  
0
1
THP17  
0
0
THP16  
0
Bits 7 to 0 : Transmit Programmable Header Pattern (THP[23:16])  
Register Name:  
Register Description:  
Address (hex):  
THPC4  
Transmit Header Pattern Control Register 4  
110B, 130B, 150B, 170B  
Bit #  
Name  
Default  
7
THP31  
0
6
THP30  
0
5
THP29  
0
4
THP28  
0
3
THP27  
0
2
THP26  
0
1
THP25  
0
0
THP24  
0
Bits 7 to 0 : Transmit Programmable Header Pattern (THP[31:24])  
127 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TFPPC  
Transmit Fill Cell Payload Pattern Control Register  
110C, 130C, 150C, 170C  
Bit #  
Name  
Default  
7
TFPP7  
0
6
TFPP6  
0
5
TFPP5  
0
4
TFPP4  
0
3
TFPP3  
0
2
TFPP2  
0
1
TFPP1  
0
0
TFPP0  
0
Bits 7 to 0 : Transmit Fill Cell Payload Pattern (TFPP[7:0]) – These eight bits indicate the value to be placed in  
the payload bytes of the fill cells when the TCPC register bit TFCP is set..  
Register Name:  
Register Description:  
Address (hex):  
TCPSR  
Transmit Cell Processor Status Register  
110E, 130E, 150E, 170E  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TECF  
0
Bits 7 to 1 : Unused.  
Bit 0 : Transmit Errored Cell Insertion Finished (TECF) – This bit is set when the number of errored cells  
indicated by the TCEN[7:0] bits in the TECC register have been transmitted. This bit is cleared when errored cell  
insertion is disabled, or a new errored cell insertion process is initiated.  
Register Name:  
Register Description:  
Address (hex):  
TCPSRL  
Transmit Cell Processor Status Register Latched  
1110, 1310, 1510, 1710  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TECFL  
0
Bits 7 to 1 : Unused.  
Bit 0 : Transmit Errored Cell Insertion Finished Latched (TECFL) – This bit is set when the TECF bit in the  
TCPSR register transitions from zero to one.  
128 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCPSRIE  
Transmit Cell Processor Status Register Interrupt Enable  
1112, 1312, 1512, 1712  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TECFIE  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit Errored Cell Insertion Finished Interrupt Enable (TECFIE) – This bit enables an interrupt if the  
TECFL bit in the TCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Transmit Cell Count (TCC[23:0]) – These twenty-four bits indicate the number of cells extracted from the  
Transmit FIFO and output in the outgoing data stream.  
Register Name:  
Register Description:  
Address (hex):  
TCCR1  
Transmit Cell Count Register 1  
1114, 1314, 1514, 1714  
Bit #  
Name  
Default  
7
TCC7  
0
6
TCC6  
0
5
TCC5  
0
4
TCC4  
0
3
TCC3  
0
2
TCC2  
0
1
TCC1  
0
0
TCC0  
0
Bits 7 to 0 : Transmit Cell Count (TCC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
TCCR2  
Transmit Cell Count Register 2  
1115, 1315, 1515, 1715  
Bit #  
Name  
Default  
7
TCC15  
0
6
TCC14  
0
5
TCC13  
0
4
TCC12  
0
3
TCC11  
0
2
TCC10  
0
1
TCC9  
0
0
TCC8  
0
Bits 7 to 0 : Transmit Cell Count (TCC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
TCCR3  
Transmit Cell Count Register 3  
1116, 1316, 1516, 1716  
Bit #  
Name  
Default  
7
TCC23  
0
6
TCC22  
0
5
TCC21  
0
4
TCC20  
0
3
TCC19  
0
2
TCC18  
0
1
TCC17  
0
0
TCC16  
0
Bits 7 to 0 : Transmit Cell Count (TCC[23:16])  
129 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.2.5 Transmit Packet Processor Registers  
Table 11-4 Transmit Packet Processor Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1100  
NAME  
FUNCTION  
-
TPPC  
TIFGC  
-
TEPC1  
TEPC2  
RES  
TPPSR  
-
TPPSRL  
-
TPPSRIE  
TPCR1  
TPCR2  
TPCR3  
-
TBCR1  
TBCR2  
TBCR3  
TBCR4  
-
Unused. Must be set = 0 for proper operation.  
Transmit Packet Processor Control Register  
Transmit Inter-Frame Gapping Control Register  
Unused. Must be set = 0 for proper operation.  
Transmit Errored Packet Control Register 1  
Transmit Errored Packet Control Register 2  
Unused. Must be set = 0 for proper operation.  
Transmit Packet Processor Status Register  
Unused. Must be set = 0 for proper operation.  
Transmit Packet Processor Status Register Latched  
Unused. Must be set = 0 for proper operation.  
Transmit Packet Processor Status Register Interrupt Enable  
Transmit Packet Count Register 1  
Transmit Packet Count Register 2  
Transmit Packet Count Register 3  
Unused. Must be set = 0 for proper operation.  
Transmit Byte Count Register 1  
Transmit Byte Count Register 2  
Transmit Byte Count Register 3  
Transmit Byte Count Register 4  
Unused. Must be set = 0 for proper operation.  
1101  
1102  
1103  
1104  
1105  
1106 – 110E  
110F  
1110  
1111  
1112  
1113  
1114  
1115  
1116  
1117  
1118  
1119  
111A  
111B  
111C – 111F  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TPPC  
Transmit Packet Processor Control Register  
1101, 1301, 1501, 1701  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TFAD  
0
4
TF16  
0
3
TIFV  
0
2
TSD  
0
1
TBRE  
0
0
TCCE  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Transmit FCS Append Disable (TFAD) – This bit controls whether or not an FCS is appended to the end  
of each packet. When 0, the calculated FCS bytes are appended to the end of the packet. When 1, the packet is  
transmitted without an FCS.  
Bit 4 : Transmit FCS-16 Enable (TF16) – When 0, the FCS processing uses a 32-bit FCS. When 1, the FCS  
processing uses a 16-bit FCS  
Bit 3 : Transmit Bit Synchronous Inter-frame Fill Value (TIFV) – When 0, inter-frame fill is done with the flag  
sequence (7Eh). When 1, inter-frame fill is done with all '1's. This bit is ignored in byte synchronous mode.  
Bit 2 : Transmit Scrambling Disable (TSD) – When 0, scrambling is performed. When 1, scrambling is disabled.  
Bit 1 : Receive Bit Reordering Enable (RBRE) – When 0, bit reordering is disabled (The first bit transmitted is  
from the MSB of the transmit FIFO byte TFD[7]). When 1, bit reordering is enabled (The first bit transmitted is from  
the LSB of the transmit FIFO byte TFD[0]).  
Bit 0 : Transmit Clear Channel Enable (TCCE) – When 0, packet processing is enabled. When 1, clear channel  
is enabled, and all packet-processing functions except scrambling and bit reordering are disabled.  
131 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIFGC  
Transmit Inter-Frame Gapping Control Register  
1102, 1302, 1502, 1702  
Bit #  
Name  
Default  
7
TIFG7  
0
6
TIFG6  
0
5
TIFG5  
0
4
TIFG4  
0
3
TIFG3  
0
2
TIFG2  
0
1
TIFG1  
0
0
TIFG0  
1
Bits 7 to 0 : Transmit Inter-Frame Gapping (TIFG[7:0]) – These eight bits indicate the number of additional flags  
and bytes of inter-frame fill to be inserted between packets. The number of flags and bytes of inter-frame fill  
between packets will be at least the value of TIFG[7:0] plus 1. Note: If inter-frame fill is set to all 1’s, a TFIG value  
of 2 or 3 will result in a flag, at least two bytes of 1’s, and a flag between packets.  
Register Name:  
Register Description:  
Address (hex):  
TEPC1  
Transmit Errored Packet Control Register 1  
1104, 1304, 1504, 1704  
Bit #  
Name  
Default  
7
TPEN7  
0
6
TPEN6  
0
5
TPEN5  
0
4
TPEN4  
0
3
TPEN3  
0
2
TPEN2  
0
1
TPEN1  
0
0
TPEN0  
0
Bits 7 to 0 : Transmit Errored Packet Insertion Number (TPEN[7:0]) – These eight bits indicate the total  
number of errored packets to be transmitted. A value of FFh results in continuous errored packet insertion at the  
specified rate.  
Register Name:  
Register Description:  
Address (hex):  
TEPC2  
Transmit Errored Packet Control Register 2  
1105, 1305, 1505, 1705  
Bit #  
Name  
Default  
7
MEIMS  
0
6
TPER6  
0
5
TPER5  
0
4
TPER4  
0
3
TPER3  
0
2
TPER2  
0
1
TPER1  
0
0
TPER0  
0
Bit 7 : Manual Error Insert Mode Select (MEIMS) – When 0, the transmit manual error insertion signal (TMEI) will  
not cause errors to be inserted. When 1, TMEI will cause an error to be inserted when it transitions from a 0 to a 1.  
Note: Enabling TMEI does not disable error insertion using TCER[6:0] and TCEN[7:0].  
Bits 6 to 0 : Transmit Errored Packet Insertion Rate (TPER[6:0]) – These seven bits indicate the rate at which  
errored packets are to be output. One out of every x * 10y packets is to be an errored packet. TPER[3:0] is the  
value x, and TPER[6:4] is the value y which has a maximum value of 6. If TPER[3:0] has a value of 0h errored  
packet insertion is disabled. If TPER[6:4] has a value of 6xh or 7xh the errored packet rate will be x * 106. A  
TPER[6:0] value of 01h results in every packet being errored. A TPER[6:0] value of 0Fh results in every 15th packet  
being errored. A TPER[6:0] value of 11h result in every 10th packet being errored. Errored packet insertion starts  
when the TEPC register is written to with a TPER[3:0] value that is non-zero. If the TEPC register is written to  
during the middle of an errored packet insertion process, the current process is halted, and a new process will be  
started using the new values of TPER[6:0] and TPEN[7:0}. Errored packet insertion ends when TPEN[7:0] errored  
packets have been transmitted.  
132 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TPPSR  
Transmit Packet Processor Status Register  
110F, 130F, 150F, 170F  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TEPF  
0
Bits 7 to 1 : Unused.  
Bit 0 : Transmit Errored Packet Insertion Finished (TEPF) – This bit is set when the number of errored packets  
indicated by the TPEN[7:0] bits in the TEPC register have been transmitted. This bit is cleared when errored  
packet insertion is disabled, or a new errored packet insertion process is initiated.  
Register Name:  
Register Description:  
Address (hex):  
TPPSRL  
Transmit Packet Processor Status Register Latched  
1111, 1311, 1511, 1711  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TEPFL  
0
Bits 7 to 1 : Unused.  
Bit 0 : Transmit Errored Packet Insertion Finished Latched (TEPFL) – This bit is set when the TEPF bit in the  
TPPSR register transitions from zero to one.  
Register Name:  
Register Description:  
Address (hex):  
TPPSRIE  
Transmit Packet Processor Status Register Interrupt Enable  
1113, 1313, 1513, 1713  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TEPFIE  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit Errored Packet Insertion Finished Interrupt Enable (TEPFIE) – This bit enables an interrupt if  
the TEPFL bit in the TPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
133 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Transmit Packet Count (TPC[23:0]) – These twenty-four bits indicate the number of packets extracted from the  
Transmit FIFO and output in the outgoing data stream.  
Register Name:  
Register Description:  
Address (hex):  
TPCR1  
Transmit Packet Count Register 1  
1114, 1314, 1514, 1714  
Bit #  
Name  
Default  
7
TPC7  
0
6
TPC6  
0
5
TPC5  
0
4
TPC4  
0
3
TPC3  
0
2
TPC2  
0
1
TPC1  
0
0
TPC0  
0
Bits 7 to 0 : Transmit Packet Count (TPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
TPCR2  
Transmit Packet Count Register 2  
1115, 1315, 1515, 1715  
Bit #  
Name  
Default  
7
TPC15  
0
6
TPC14  
0
5
TPC13  
0
4
TPC12  
0
3
TPC11  
0
2
TPC10  
0
1
TPC9  
0
0
TPC8  
0
Bits 7 to 0 : Transmit Packet Count (TPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
TPCR3  
Transmit Packet Count Register 3  
1116, 1316, 1516, 1716  
Bit #  
Name  
Default  
7
TPC23  
0
6
TPC22  
0
5
TPC21  
0
4
TPC20  
0
3
TPC19  
0
2
TPC18  
0
1
TPC17  
0
0
TPC16  
0
Bits 7 to 0 : Transmit Packet Count (TPC[23:16])  
134 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Transmit Byte Count (TBC[31:0]) – These thirty-two bits indicate the number of packet bytes inserted in the  
outgoing data stream.  
Register Name:  
Register Description:  
Address (hex):  
TBCR1  
Transmit Byte Count Register 1  
1118, 1318, 1518, 1718  
Bit #  
Name  
Default  
7
TBC7  
0
6
TBC6  
0
5
TBC5  
0
4
TBC4  
0
3
TBC3  
0
2
TBC2  
0
1
TBC1  
0
0
TBC0  
0
Bits 7 to 0 : Transmit Byte Count (TBC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
TBCR2  
Transmit Byte Count Register 2  
1119, 1319, 1519, 1719  
Bit #  
Name  
Default  
7
TBC15  
0
6
TBC14  
0
5
TBC13  
0
4
TBC12  
0
3
TBC11  
0
2
TBC10  
0
1
TBC9  
0
0
TBC8  
0
Bits 7 to 0 : Transmit Byte Count (TBC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
TBCR3  
Transmit Byte Count Register 3  
111A, 131A, 151A, 171A  
Bit #  
Name  
Default  
7
TBC23  
0
6
TBC22  
0
5
TBC21  
0
4
TBC20  
0
3
TBC19  
0
2
TBC18  
0
1
TBC17  
0
0
TBC16  
0
Bits 7 to 0 : Transmit Byte Count (TBC[23:16])  
Register Name:  
Register Description:  
Address (hex):  
TBCR4  
Transmit Byte Count Register 4  
111B, 131B, 151B, 171B  
Bit #  
Name  
Default  
15  
TBC31  
0
14  
TBC30  
0
13  
TBC29  
0
12  
TBC28  
0
11  
TBC27  
0
10  
TBC26  
0
9
TBC25  
0
8
TBC24  
0
Bits 7 to 0 : Transmit Byte Count (TBC[31:24])  
135 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.2.6 Receive Cell Processor Registers  
Table 11-5 Receive Cell Processor Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1000  
NAME  
FUNCTION  
RCPC1  
RCPC2  
-
Receive Cell Processor Control Register 1  
1001  
1002  
1003  
1004  
1005  
1006  
1007  
1008  
1009  
100A  
100B  
100C  
100D  
100E  
100F  
Receive Cell Processor Control Register 2  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Receive Header Pattern Control Register 1  
Receive Header Pattern Control Register 2  
Receive Header Pattern Control Register 3  
Receive Header Pattern Control Register 4  
Receive Header Pattern Mask Control Register 1  
Receive Header Pattern Mask Control Register 2  
Receive Header Pattern Mask Control Register 3  
Receive Header Pattern Mask Control Register 4  
Receive LCD Threshold Control Register 1  
Receive LCD Threshold Control Register 2  
Receive Cell Processor Status Register 1  
Receive Cell Processor Status Register 2  
-
RHPC1  
RHPC2  
RHPC3  
RHPC4  
RHPMC1  
RHPMC2  
RHPMC3  
RHPMC4  
RLTC1  
RLTC2  
RCPSR1  
RCPSR2  
1010  
1011  
1012  
1013  
RCPSRL1 Receive Cell Processor Status Register Latched 1  
RCPSRL2 Receive Cell Processor Status Register Latched 2  
RCPSRIE1 Receive Cell Processor Register Interrupt Enable 1  
RCPSRIE2 Receive Cell Processor Register Interrupt Enable 2  
1014  
1015  
1016  
1017  
RCCR1  
RCCR2  
RCCR3  
-
Receive Cell Count Register 1  
Receive Cell Count Register 2  
Receive Cell Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Errored Header Count Register 1  
Receive Errored Header Count Register 2  
Receive Errored Header Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Header Pattern Cell Count Register 1  
Receive Header Pattern Cell Count Register 2  
Receive Header Pattern Cell Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Corrected Cell Count Register 1  
Receive Corrected Cell Count Register 2  
Receive Corrected Cell Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Filtered Cell Count Register 1  
Receive Filtered Cell Count Register 2  
Receive Filtered Cell Count Register 3  
Unused. Must be set = 0 for proper operation.  
1018  
1019  
101A  
101B  
101C  
101D  
101E  
4101F  
1020  
1021  
1022  
1023  
1024  
1025  
1026  
REHCR1  
REHCR2  
REHCR3  
-
RHPCR1  
RHPCR2  
RHPCR3  
-
RCCCR1  
RCCCR2  
RCCCR3  
-
RFCCR1  
RFCCR2  
RFCCR3  
-
1027-103F  
136 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPC1  
Receive Cell Processor Control Register 1  
1000, 1200, 1400, 1600  
Bit #  
Name  
Default  
7
RROC1  
0
6
RROC0  
0
5
RCPAD  
0
4
RHECD  
0
3
RHDE  
0
2
RDD  
0
1
RBRE  
0
0
RCCE  
0
Bit 7 & 6 : Receive Error Monitoring Required OK Cells (RROC[1:0]) – These two bits indicate the number of  
good cells required to transition from the "Detection" state to the "Correction" state.  
00 = 1 good cell is required.  
01 = 2 good cells are required.  
10 = 4 good cells are required.  
11 = 8 good cells are required.  
Bit 5 : Receive HEC Coset Polynomial Addition Disable (RCPAD) – When 0, the HEC coset polynomial  
addition is performed prior to checking the HEC byte. When 1, HEC coset polynomial addition is disabled  
Bit 4 : Receive Header Error Correction Disable (RHECD) – When 0, single bit header error correction is  
enabled. When 1, header error correction is disabled and all errors are treated as an uncorrectable error.  
Bit 3 : Receive Cell Header Descrambling Enable (RHDE) – When 0, only the cell payload will be descrambled.  
When 1, the entire data stream (cell header and payload) is descrambled. This bit is ignored if descrambling is  
disabled or DSS descrambling is enabled. When clear channel is enabled, the entire data stream will be  
descrambled if descrambling is enabled.  
Bit 2 : Receive Descrambling Disable (RDD) – When 0, descrambling is performed. When 1, descrambling is  
disabled.  
Bit 1 : Receive Bit Reordering Enable (RBRE) – When 0, bit reordering is disabled (The first bit received is  
stored in the MSB of the receive FIFO byte RFD[7]). When 1, bit reordering is enabled (The first bit received is  
stored in the LSB of the receive FIFO byte RFD[0]).  
Bit 0 : Receive Clear Channel Enable (RCCE) – When 0, cell processing is enabled. When 1, clear channel is  
enabled, and all cell processing functions except descrambling and bit reordering are disabled.  
137 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPC2  
Receive Cell Processor Control Register 2  
1001, 1201, 1401, 1601  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RDDE  
0
RDHE  
0
RECED  
0
RHPM1  
0
RHPM0  
0
RICFD  
0
RUCFE  
0
RICFE  
0
Bit 7 : Receive DSS Descrambling Enable (RDDE) – When 0, self-synchronous descrambling is enabled. When  
1, DSS descrambling is enabled. This bit is ignored if descrambling is disabled. Note: In byte synchronous and  
clear channel modes self-synchronous descrambling is enabled regardless of the setting of this bit.  
Bit 6 : Receive DQDB HEC Processing Enable (RDHE) – When 0, the HEC is calculated over all four header  
bytes. When 1, only the last three header bytes are used for HEC calculation.  
Bit 5 : Receive Errored Cell Extraction Disable (RECED) – When 0, errored cells are extracted. When 1, errored  
cells are passed on.  
Bit 4 to 3 : Receive Header Pattern Comparison Mode (RHPM[1:0]) – These two bits control the operation of  
the header pattern comparison function.  
00 = Count match: Cells that match the header pattern are counted.  
01 = Count no match - Cells that do not match the header pattern are counted.  
10 = Discard match - Cells that match the header pattern are counted and discarded.  
11 = Discard no match - Cells that do not match the header pattern are counted and discarded.  
Bit 2 : Receive Idle Cell Filtering Disable (RICFD) – When 0, idle cells are discarded. When 1, idle cells are  
passed on.  
Bit 1 : Receive Unassigned Cell Filtering Enable (RUCFE) – When 0, unassigned cells are passed on. When 1,  
unassigned cells are counted and discarded.  
Bit 0 : Receive Invalid Cell Filtering Enable (RICFE) – When 0, invalid cells are passed on. When 1, invalid cells  
are discarded.  
138 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Header Pattern (RHP[31:0]) – These 32 bits indicate the receive header bit pattern to be detected by the  
header pattern comparison function.  
Register Name:  
Register Description:  
Address (hex):  
RHPC1  
Receive Header Pattern Control Register 1  
1004, 1204, 1404, 1604  
Bit #  
Name  
Default  
7
RHP7  
0
6
RHP6  
0
5
RHP5  
0
4
RHP4  
0
3
RHP3  
0
2
RHP2  
0
1
RHP1  
0
0
RHP0  
0
Bit 7 to 0 : Receive Header Pattern (RHP[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RHPC2  
Receive Header Pattern Control Register 2  
1005, 1205, 1405, 1605  
Bit #  
Name  
Default  
7
RHP15  
0
6
RHP14  
0
5
RHP13  
0
4
RHP12  
0
3
RHP11  
0
2
RHP10  
0
1
RHP9  
0
0
RHP8  
0
Bits 7 to 0 : Receive Header Pattern (RHP[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RHPC3  
Receive Header Pattern Control Register 3  
1006, 1206, 1406, 1606  
Bit #  
Name  
Default  
7
RHP23  
0
6
RHP22  
0
5
RHP21  
0
4
RHP20  
0
3
RHP19  
0
2
RHP18  
0
1
RHP17  
0
0
RHP16  
0
Bits 7 to 0 : Receive Header Pattern (RHP[23:16])  
Register Name:  
Register Description:  
Address (hex):  
RHPC4  
Receive Header Pattern Control Register 4  
1007, 1207, 1407, 1607  
Bit #  
Name  
Default  
7
RHP31  
0
6
RHP30  
0
5
RHP29  
0
4
RHP28  
0
3
RHP27  
0
2
RHP26  
0
1
RHP25  
0
0
RHP24  
0
Bits 7 to 0 : Receive Header Pattern (RHP[31:24])  
139 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Header Pattern Comparison Disable (RHPD[31:0]) – These 32 bits indicate whether or not the  
associated header bit is checked by the header pattern comparison function. If RHPD[x] is high, the header bit x is  
ignored during the header pattern comparison (don't care). If RHPD[x] is low, the associated bit in the header must  
match RHP[x] in the receive header pattern control register RHPC.  
Register Name:  
Register Description:  
Address (hex):  
RHPMC1  
Receive Header Pattern Mask Control Register 1  
1008, 1208, 1408, 1608  
Bit #  
Name  
Default  
7
RHPD7  
0
6
RHPD6  
0
5
RHPD5  
0
4
RHPD4  
0
3
RHPD3  
0
2
RHPD2  
0
1
RHPD1  
0
0
RHPD0  
0
Bits 7 to 0 : Receive Header Pattern Comparison Disable (RHPD[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RHPMC2  
Receive Header Pattern Mask Control Register 2  
1009, 1209, 1409, 1609  
Bit #  
Name  
Default  
15  
RHPD15  
0
14  
RHPD14  
0
13  
RHPD13  
0
12  
RHPD12  
0
11  
RHPD11  
0
10  
RHPD10  
0
9
RHPD9  
0
8
RHPD8  
0
Bits 7 to 0 : Receive Header Pattern Comparison Disable (RHPD[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RHPMC3  
Receive Header Pattern Mask Control Register 3  
100A, 120A, 140A, 160A  
Bit #  
Name  
Default  
7
RHPD23  
0
6
RHPD22  
0
5
RHPD21  
0
4
RHPD20  
0
3
RHPD19  
0
2
RHPD18  
0
1
RHPD17  
0
0
RHPD16  
0
Bits 7 to 0 : Receive Header Pattern Comparison Disable (RHPD[23:16])  
Register Name:  
Register Description:  
Address (hex):  
RHPMC4  
Receive Header Pattern Mask Control Register 4  
100B, 120B, 140B, 160B  
Bit #  
Name  
Default  
15  
RHPD31  
0
14  
RHPD30  
0
13  
RHPD29  
0
12  
RHPD28  
0
11  
RHPD27  
0
10  
RHPD26  
0
9
RHPD25  
0
8
RHPD24  
0
Bits 7 to 0 : Receive Header Pattern Comparison Disable (RHPD[31:24])  
140 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLTC1  
Receive LCD Threshold Control Register1  
100C, 120C, 140C, 160C  
Bit #  
Name  
Default  
7
RLT7  
0
6
RLT6  
1
5
RLT5  
1
4
RLT4  
0
3
RLT3  
1
2
RLT2  
0
1
RLT1  
0
0
RLT0  
0
Bits 7 to 0 : Receive LCD Threshold (RLT[7:0]) – These sixteen bits indicate the number of consecutive cell  
periods the cell delineation state machine must be in an Out of Cell Delineation (OCD) condition before it declares  
or terminate a Loss of Cell Delineation (LCD) condition. A value of 0000h causes LCD to be declared at the same  
time as OCD.  
Register Name:  
Register Description:  
Address (hex):  
RLTC2  
Receive LCD Threshold Control Register2  
100D, 120D, 140D, 160D  
Bit #  
Name  
Default  
7
RLT15  
0
6
RLT14  
0
5
RLT13  
0
4
RLT12  
0
3
RLT11  
0
2
RLT10  
0
1
RLT9  
0
0
RLT8  
1
Bits 7 to 0 : Receive LCD Threshold (RLT[15:8]) – These sixteen bits indicate the number of consecutive cell  
periods the cell delineation state machine must be in an Out of Cell Delineation (OCD) condition before it declares  
or terminate a Loss of Cell Delineation (LCD) condition. A value of 0000h causes LCD to be declared at the same  
time as OCD.  
141 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPSR1  
Receive Cell Processor Status Register1  
100E, 120E, 140E, 160E  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
RECC  
0
1
RHPC  
0
0
RCHC  
0
Bits 7 to 3 : Unused.  
Bit 2 : Receive Errored Header Cell Count (RECC) – This read only bit indicates that the receive errored header  
cell count is non-zero.  
Bit 1 : Receive Header Pattern Cell Count (RHPC) – This read only bit indicates that the receive header pattern  
comparison cell count is non-zero.  
Bit 0 : Receive Corrected Cell Count (RCHC) – This read only bit indicates that the receive corrected header cell  
count is non-zero.  
Register Name:  
Register Description:  
Address (hex):  
RCPSR2  
Receive Cell Processor Status Register2  
100F, 120F, 140F, 160F  
Bit #  
Name  
Default  
7
SPR  
0
6
--  
0
5
--  
0
4
--  
0
3
OOS  
0
2
--  
0
1
OCD  
1
0
LCD  
0
Bit 7 : Spare Status Bit (SPR) – This bit is a spare status bit reserved for future use. It indicates the current value  
of the RCPC2.SPARE bit.  
Bits 6 to 4 : Unused.  
Bit 3 : Out Of Sync (OOS) – This read only bit indicates that a DSS Out Of Sync (OOS) state exists. DSS OOS  
occurs when the DSS Scrambler Synchronization state machine is in the "Load" or "Verify" state, and DSS  
scrambling has been enabled.  
Bit 2 : Unused.  
Bit 1 : Out Of Cell Delineation (OCD) – This read only bit indicates that an Out of Cell Delineation condition  
(OCD) exists. When DSS scrambling is disabled, OCD occurs when the HEC Error Monitoring state machine is in  
the "OCD" state. When DSS scrambling is enabled, OCD occurs when the DSS OCD Detection state machine is in  
the "OCD" state.  
Bit 0 : Loss Of Cell Delineation (LCD) – This read only bit indicate that a Loss of Cell Delineation state exists.  
LCD occurs when OCD persists for the period programmed in the LCD threshold control register RLTC.  
142 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPSRL1  
Receive Cell Processor Status Register Latched 1  
1010, 1210, 1410, 1610  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RECL  
0
RCHL  
0
RIDL  
0
RUDL  
0
RIVDL  
0
RECCL  
0
RHPCL  
0
RCHCL  
0
Bit 7 : Receive Errored Header Cell Latched (RECL) – This bit is set when a cell with an errored header is  
discarded.  
Bit 6 : Receive Corrected Header Cell Latched (RCHL) – This bit is set when a cell with a single header error is  
corrected.  
Bit 5 : Receive Idle Cell Detection Latched (RIDL) – This bit is set when an idle cell is discarded.  
Bit 4 : Receive Unassigned Cell Detection Latched (RUDL) – This bit is set when an unassigned cell is  
discarded.  
Bit 3 : Receive Invalid Cell Detection Latched (RIVDL) – This bit is set when an invalid cell is discarded.  
Bit 2 : Receive Errored Header Cell Count Latched (RECCL) – This bit is set when the RECC bit in the RCPSR  
register transitions from zero to one.  
Bit 1 : Receive Header Pattern Cell Count Latched (RHPCL) – This bit is set when the RHPC bit in the RCPSR  
register transitions from zero to one.  
Bit 0 : Receive Corrected Header Cell Count Latched (RCHCL) – This bit is set when the RCHC bit in the  
RCPSR register transitions from zero to one.  
Register Name:  
Register Description:  
Address (hex):  
RCPSRL2  
Receive Cell Processor Status Register Latched 2  
1011, 1211, 1411, 1611  
Bit #  
Name  
Default  
7
SPRL  
0
6
--  
0
5
--  
0
4
--  
0
3
OOSL  
0
2
COCDL  
0
1
OCDCL  
0
0
LCDCL  
0
Bit 7 : Spare Change Latched (SPRL) – This bit is set when the SPR bit changes state.  
Bits 6 to 4 : Unused  
Bit 3 : Out Of Sync Change Latched (OOSL) – This bit is set when the OOS bit in the RCPSR2 register changes  
state.  
Bit 2 : Change Of Cell Delineation Latched (COCDL) – This bit is set when the data path cell counters are  
updated with a new cell delineation that is different from the previous cell delineation.  
Bit 1 : Out Of Cell Delineation Change Latched (OCDCL) – This bit is set when the OCD bit in the RCPSR2  
register changes state. Note: Immediately after a reset, this bit will be set to one.  
Bit 0 : Loss Of Cell Delineation Change Latched (LCDCL) – This bit is set when the LCD bit in the RCPSR2  
register changes state  
143 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPSRIE  
Receive Cell Processor Register Interrupt Enable  
1012, 1212, 1412, 1612  
Bit #  
Name  
Default  
7
RECIE  
0
6
RCHIE  
0
5
RIDIE  
0
4
RUDIE  
0
3
RIVDIE  
0
2
RECCIE  
0
1
RHPCIE  
0
0
RCHCIE  
0
Bit 7 : Receive Errored Header Cell Interrupt Enable (RECIE) – This bit enables an interrupt if the RECL bit in  
the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 6 : Receive Corrected Header Cell Interrupt Enable (RCHIE) – This bit enables an interrupt if the RCHL bit in  
the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 5 : Receive Idle Cell Detection Interrupt Enable (RIDIE) – This bit enables an interrupt if the RIDL bit in the  
RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 4 : Receive Unassigned Cell Detection Interrupt Enable (RUDIE) – This bit enables an interrupt if the RUDL  
bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 3 : Receive Invalid Cell Detection Interrupt Enable (RIVDIE) – This bit enables an interrupt if the RIVDL bit  
in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 2 : Receive Errored Header Cell Count Interrupt Enable (RECCIE) – This bit enables an interrupt if the  
RECCL bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 1 : Receive Header Pattern Cell Count Interrupt Enable (RHPCIE) – This bit enables an interrupt if the  
RHFCL bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 0 : Receive Corrected Header Cell Count Interrupt Enable (RCHCIE) – This bit enables an interrupt if the  
RCHCL bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCPSRIE  
Receive Cell Processor Register Interrupt Enable  
1013, 1213, 1413, 1613  
Bit #  
Name  
Default  
7
SPRIE  
0
6
--  
0
5
--  
0
4
--  
0
3
OOSIE  
0
2
COCDIE  
0
1
OCDCIE  
0
0
LCDCIE  
0
Bit 7 : Spare Change Interrupt Enable (SPRIE) – This bit enables an interrupt if the SPRL bit is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bits 6 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Out Of Sync Change Interrupt Enable (OOSIE) – This bit enables an interrupt if the OOSL bit in the  
RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 2 : Change Of Cell Delineation Interrupt Enable (COCDIE) – This bit enables an interrupt if the COCDL bit  
in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 1 : Out Of Cell Delineation Change Interrupt Enable (OCDCIE) – This bit enables an interrupt if the OCDCL  
bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 0 : Loss Of Cell Delineation Change Interrupt Enable (LCDCIE) – This bit enables an interrupt if the LCDCL  
bit in the RCPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
145 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Cell Count (RCC[23:0]) – These twenty-four bits indicate the number of cells stored in the receive FIFO.  
Note: Cells discarded due to system loopback or an overflow condition will be included in this count.  
Register Name:  
Register Description:  
Address (hex):  
RCCR1  
Receive Cell Count Register 1  
1014, 1214, 1414, 1614  
Bit #  
Name  
Default  
7
RCC7  
0
6
RCC6  
0
5
RCC5  
0
4
RCC4  
0
3
RCC3  
0
2
RCC2  
0
1
RCC1  
0
0
RCC0  
0
Bits 7 to 0 : Receive Cell Count (RCC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RCCR2  
Receive Cell Count Register 2  
1015, 1215, 1415, 1615  
Bit #  
Name  
Default  
15  
RCC15  
0
14  
RCC14  
0
13  
RCC13  
0
12  
RCC12  
0
11  
RCC11  
0
10  
RCC10  
0
9
RCC9  
0
8
RCC8  
0
Bits 7 to 0 : Receive Cell Count (RCC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RCCR3  
Receive Cell Count Register 3  
1016, 1216, 1416, 1616  
Bit #  
Name  
Default  
7
RCC23  
0
6
RCC22  
0
5
RCC21  
0
4
RCC20  
0
3
RCC19  
0
2
RCC18  
0
1
RCC17  
0
0
RCC16  
0
Bits 7 to 0 : Receive Cell Count (RCC[23:16])  
146 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Errored Header Count (RECC[23:0]) – These twenty-four bits indicate the number of cells received with  
uncorrected header errors and discarded. If errored cell extraction is disabled, this count will be zero. Cells  
included in this count will not be included in any other count.  
Register Name:  
Register Description:  
Address (hex):  
REHCR1  
Receive Errored Header Count Register 1  
1018, 1218, 1418, 1618  
Bit #  
Name  
Default  
7
RECC7  
0
6
RECC6  
0
5
RECC5  
0
4
RECC4  
0
3
RECC3  
0
2
RECC2  
0
1
RECC1  
0
0
RECC0  
0
Bits 7 to 0 : Receive Errored Header Count (RECC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
REHCR2  
Receive Errored Header Count Register 2  
1019, 1219, 1419, 1619  
Bit #  
Name  
Default  
7
RECC15  
0
6
RECC14  
0
5
RECC13  
0
4
RECC12  
0
3
RECC11  
0
2
RECC10  
0
1
RECC9  
0
0
RECC8  
0
Bits 7 to 0 : Receive Errored Header Count (RECC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
REHCR3  
Receive Errored Header Count Register 3  
101A, 121A, 141A, 161A  
Bit #  
Name  
Default  
7
RECC23  
0
6
RECC22  
0
5
RECC21  
0
4
RECC20  
0
3
RECC19  
0
2
RECC18  
0
1
0
RECC17 RECC16  
0
0
Bits 7 to 0 : Receive Errored Header Count (RECC[23:16])  
147 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Header Pattern Comparison Cell Count (RHPC[23:0]) – These twenty-four bits indicate the number of  
cells identified during the header pattern comparison processes. In the header pattern comparison count and  
discard match modes, this will be a count of cells with a matching header. In the header pattern comparison count  
and discard no match modes, this will be a count of cells without a matching header. In the header pattern  
comparison count (match or no match) modes, this count will also be included in the receive cell count register  
(RCCR). In the header pattern comparison discard (match or no match) modes, this count will not be included in  
any other count.  
Register Name:  
Register Description:  
Address (hex):  
RHPCR1  
Receive Header Pattern Cell Count Register #1  
101C, 121C, 141C, 161C  
Bit #  
Name  
Default  
7
RHPC7  
0
6
RHPC6  
0
5
RHPC5  
0
4
RHPC4  
0
3
RHPC3  
0
2
RHPC2  
0
1
RHPC1  
0
0
RHPC0  
0
Bits 7 to 0 : Receive Header Pattern Comparison Cell Count (RHPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RHPCR2  
Receive Header Pattern Cell Count Register 2  
101D, 121D, 141D, 161D  
Bit #  
Name  
Default  
7
RHPC15  
0
6
RHPC14  
0
5
RHPC13  
0
4
RHPC12  
0
3
RHPC11  
0
2
RHPC10  
0
1
RHPC9  
0
0
RHPC8  
0
Bits 7 to 0 : Receive Header Pattern Comparison Cell Count (RHPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RHPCR3  
Receive Header Pattern Cell Count Register 3  
101E, 121E, 141E, 161E  
Bit #  
Name  
Default  
7
RHPC23  
0
6
RHPC22  
0
5
RHPC21  
0
4
RHPC20  
0
3
RHPC19  
0
2
RHPC18  
0
1
RHPC17  
0
0
RHPC16  
0
Bits 7 to 0 : Receive Header Pattern Comparison Cell Count (RHPC[23:16])  
148 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Corrected Header Count (RCHC[23:0]) – These twenty-four bits indicate the number of cells that have  
had header errors corrected. If header error correction is disabled, this count will be zero. This count will be  
included in the receive cell count register (RCCR), receive filtered idle/unassigned/invalid cell count register  
(RFCCR), or receive header pattern cell count register (RHPCR).  
Register Name:  
Register Description:  
Address (hex):  
RCCCR1  
Receive Corrected Cell Count Register #1  
1020, 1220, 1420, 1620  
Bit #  
Name  
Default  
7
RCHC7  
0
6
RCHC6  
0
5
RCHC5  
0
4
RCHC4  
0
3
RCHC3  
0
2
RCHC2  
0
1
RCHC1  
0
0
RCHC0  
0
Bits 7 to 0 : Receive Corrected Header Count (RCHC[15:0])  
Register Name:  
Register Description:  
Address (hex):  
RCCCR2  
Receive Corrected Cell Count Register 2  
1021, 1221, 1421, 1621  
Bit #  
Name  
Default  
15  
RCHC15  
0
14  
RCHC14  
0
13  
RCHC13  
0
12  
RCHC12  
0
11  
RCHC11  
0
10  
RCHC10  
0
9
RCHC9  
0
8
RCHC8  
0
Bits 7 to 0 : Receive Corrected Header Count (RCHC[15:0])  
Register Name:  
Register Description:  
Address (hex):  
RCCCR3  
Receive Corrected Cell Count Register 3  
1022, 1222, 1422, 1622  
Bit #  
Name  
Default  
7
RCHC23  
0
6
RCHC22  
0
5
RCHC21  
0
4
RCHC20  
0
3
RCHC19  
0
2
RCHC18  
0
1
0
RCHC17 RCHC16  
0
0
Bits 7 to 0 : Receive Corrected Header Count (RCHC[23:16])  
149 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Filtered Cell Count (RFCC[23:0]) – These twenty-four bits indicate the number of cells that were  
discarded during the cell filtering processes (idle, unassigned, and/or invalid). If all cell filtering is disabled, this  
count will be zero. Cells included in this count will not be included in any other count.  
Register Name:  
Register Description:  
Address (hex):  
RFCCR1  
Receive Filtered Idle/Unassigned/Invalid Cell Count Register 1  
1024, 1224, 1424, 1624  
Bit #  
Name  
Default  
7
RFCC7  
0
6
RFCC6  
0
5
RFCC5  
0
4
RFCC4  
0
3
RFCC3  
0
2
RFCC2  
0
1
RFCC1  
0
0
RFCC0  
0
Bits 7 to 0 : Receive Filtered Cell Count (RFCC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RFCCR2  
Receive Filtered Idle/Unassigned/Invalid Cell Count Register 2  
1025, 1225, 1425, 1625  
Bit #  
Name  
Default  
7
RFCC15  
0
6
RFCC14  
0
5
RFCC13  
0
4
RFCC12  
0
3
RFCC11  
0
2
RFCC10  
0
1
RFCC9  
0
0
RFCC8  
0
Bits 7 to 0 : Receive Filtered Cell Count (RFCC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RFCCR3  
Receive Filtered Idle/Unassigned/Invalid Cell Count Register 3  
1026, 1226, 1426, 1626  
Bit #  
Name  
Default  
7
RFCC23  
0
6
RFCC22  
0
5
RFCC21  
0
4
RFCC20  
0
3
RFCC19  
0
2
RFCC18  
0
1
0
RFCC17 RFCC16  
0
0
Bits 7 to 0 : Receive Filtered Cell Count (RFCC[23:16])  
150 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.2.7 Receive Packet Processor Registers  
Table 11-6 Receive Packet Processor Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1000  
NAME  
FUNCTION  
RPPC1  
RPPC2  
RMPSC1  
RMPSC2  
-
RPPSR  
-
RPPSRL  
-
RPPSRIE  
RPCR1  
RPCR2  
RPCR3  
-
RFPCR1  
RFPCR2  
RFPCR3  
-
RAPCR1  
RAPCR2  
RAPCR3  
-
RSPCR1  
RSPCR2  
RSPCR3  
-
Receive Packet Processor Control Register 1  
Receive Packet Processor Control Register 2  
Receive Maximum Packet Size Control Register 1  
Receive Maximum Packet Size Control Register 2  
Unused. Must be set = 0 for proper operation.  
Receive Packet Processor Status Register  
Unused. Must be set = 0 for proper operation.  
Receive Packet Processor Status Register Latched  
Unused. Must be set = 0 for proper operation.  
Receive Packet Processor Status Register Interrupt Enable  
Receive Packet Count Register 1  
1001  
1002  
1003  
1004 – 100E  
100F  
1010  
1011  
1012  
1013  
1014  
1015  
1016  
1017  
1018  
1019  
101A  
101B  
101C  
101D  
101E  
101F  
Receive Packet Count Register 2  
Receive Packet Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive FCS Errored Packet Count Register 1  
Receive FCS Errored Packet Count Register 2  
Receive FCS Errored Packet Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Aborted Packet Count Register 1  
Receive Aborted Packet Count Register 2  
Receive Aborted Packet Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Size Violation Packet Count Register 1  
Receive Size Violation Packet Count Register 2  
Receive Size Violation Packet Count Register 3  
Unused. Must be set = 0 for proper operation.  
Receive Byte Count Register 1  
Receive Byte Count Register 2  
Receive Byte Count Register 3  
Receive Byte Count Register 4  
Receive Aborted Byte Count Register 1  
Receive Aborted Byte Count Register 2  
Receive Aborted Byte Count Register 3  
Receive Aborted Byte Count Register 4  
Unused. Must be set = 0 for proper operation.  
1020  
1021  
1022  
1023 - 1027  
1028  
RBCR1  
RBCR2  
RBCR3  
RBCR4  
RABCR1  
RABCR2  
RABCR3  
RABCR4  
--  
1029  
102A  
102B  
102C  
102D  
102E  
102F  
1030 – 103F  
151 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RPPC1  
Receive Packet Processor Control Register 1  
1000, 1200, 1400, 1600  
Bit #  
Name  
Default  
7
SPARE  
0
6
-
0
5
RFPD  
0
4
RF16  
0
3
RFED  
0
2
RDD  
0
1
RBRE  
0
0
RCCE  
0
Bit 7 : Spare Configuration Bit (SPARE) – This bit is a spare configuration bit reserved for future use. It can be  
written to and read from, however it does not effect the operation of the CELL / PACKET INTERFACE.  
Bit 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Receive FCS Processing Disable (RFPD) – When 0, FCS processing is performed (the packets have an  
FCS appended). When 1, FCS processing is disabled (the packets do not have an FCS appended).  
Bit 4 : Receive FCS-16 Enable (RF16) – When 0, the error checking circuit uses a 32-bit FCS. When 1, the error  
checking circuit uses a 16-bit FCS. This bit is ignored when FCS processing is disabled.  
Bit 3 : Receive FCS Extraction Disable (RFED) – When 0, the FCS bytes are discarded. When 1, the FCS bytes  
are passed on. This bit is ignored when FCS processing is disabled.  
Bit 2 : Receive Descrambling Disable (RDD) – When 0, descrambling is performed. When 1, descrambling is  
disabled.  
Bit 1 : Receive Bit Reordering Enable (RBRE) – When 0, bit reordering is disabled (The first bit received is  
stored in the MSB of the receive FIFO byte RFD[7]). When 1, bit reordering is enabled (The first bit received is  
stored in the LSB of the receive FIFO byte RFD[0]).  
Bit 0 : Receive Clear Channel Enable (RCCE) – When 0, packet processing is enabled. When 1, clear channel is  
enabled, and all packet-processing functions except descrambling and bit reordering are disabled.  
Register Name:  
Register Description:  
Address (hex):  
RPPC2  
Receive Packet Processor Control Register 2  
1001, 1201, 1401, 1601  
Bit #  
Name  
Default  
7
RMNS7  
0
6
RMNS6  
0
5
RMNS5  
0
4
RMNS4  
0
3
RMNS3  
0
2
RMNS2  
0
1
RMNS1  
0
0
RMNS0  
0
Bits 7 to 0 : Receive Minimum Packet Size (RMNS[7:0]) – These eight bits indicate the minimum allowable  
packet size in bytes. The size includes the FCS bytes, but excludes bit/byte stuffing. Note: In FCS-32 mode,  
packets with six bytes are the minimum packet size allowed. In FCS-16 mode, packets with four bytes are the  
minimum packet size allowed. When FCS processing is disabled, packets with two bytes are the minimum packet  
size allowed.  
152 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RMPSC1  
Receive Maximum Packet Size Control Register 1  
1002, 1202, 1402, 1602  
Bit #  
Name  
Default  
7
RMX7  
0
6
RMX6  
0
5
RMX5  
0
4
RMX4  
0
3
RMX3  
0
2
RMX2  
0
1
RMX1  
0
0
RMX0  
0
Bits 7 to 0 : Receive Maximum Packet Size (RMX[7:0]) – These sixteen bits indicate the maximum allowable  
packet size in bytes. The size includes the FCS bytes, but excludes bit/byte stuffing. Note: If the maximum packet  
length is less than the minimum packet length, all packets will be discarded. When packet processing is disabled,  
these sixteen bits indicate the "packet" size the incoming data is to be broken into.  
Register Name:  
Register Description:  
Address (hex):  
RMPSC2  
Receive Maximum Packet Size Control Register 2  
1003, 1203, 1403, 1603  
Bit #  
Name  
Default  
7
RMX15  
0
6
RMX14  
0
5
RMX13  
0
4
RMX12  
0
3
RMX11  
0
2
RMX10  
1
1
RMX9  
1
0
RMX8  
0
Bits 7 to 0 : Receive Maximum Packet Size (RMX[15:8]) – These sixteen bits indicate the maximum allowable  
packet size in bytes. The size includes the FCS bytes, but excludes bit/byte stuffing. Note: If the maximum packet  
length is less than the minimum packet length, all packets will be discarded. When packet processing is disabled,  
these sixteen bits indicate the "packet" size the incoming data is to be broken into.  
153 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RPPSR  
Receive Packet Processor Status Register  
100F, 120F, 140F, 160F  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
REPC  
0
1
RAPC  
0
0
RSPC  
0
Bits 7 to 3 : Unused.  
Bit 2 : Receive FCS Errored Packet Count (REPC) – This read only bit indicates that the receive FCS errored  
packet count is non-zero.  
Bit 1 : Receive Aborted Packet Count (RAPC) – This read only bit indicates that the receive aborted packet  
count is non-zero.  
Bit 0 : Receive Size Violation Packet Count (RSPC) – This read only bit indicates that the receive size violation  
packet count is non-zero.  
154 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RPPSRL  
Receive Packet Processor Status Register Latched  
1011, 1211, 1411, 1611  
Bit #  
Name  
Default  
7
REPL  
0
6
RAPL  
0
5
RIPDL  
0
4
RSPDL  
0
3
RLPDL  
0
2
REPCL  
0
1
RAPCL  
0
0
RSPCL  
0
Bit 7 : Receive FCS Errored Packet Latched (REPL) – This bit is set when a packet with an errored FCS is  
detected.  
Bit 6 : Receive Aborted Packet Latched (RAPL) – This bit is set when a packet with an abort indication is  
detected.  
Bit 5 : Receive Invalid Packet Detected Latched (RIPDL) – This bit is set when a packet with a non-integer  
number of bytes is detected.  
Bit 4 : Receive Small Packet Detected Latched (RSPDL) – This bit is set when a packet smaller than the  
minimum packet size is detected.  
Bit 3 : Receive Large Packet Detected Latched (RLPDL) – This bit is set when a packet larger than the  
maximum packet size is detected.  
Bit 2 : Receive FCS Errored Packet Count Latched (REPCL) – This bit is set when the REPC bit in the RPPSR  
register transitions from zero to one.  
Bit 1 : Receive Aborted Packet Count Latched (RAPCL) – This bit is set when the RAPC bit in the RPPSR  
register transitions from zero to one.  
Bit 0 : Receive Size Violation Packet Count Latched (RSPCL) – This bit is set when the RSPC bit in the RPPSR  
register transitions from zero to one.  
155 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RPPSRIE  
Receive Packet Processor Status Register Interrupt Enable  
1013, 1213, 1413, 1613  
Bit #  
Name  
Default  
7
REPIE  
0
6
RAPIE  
0
5
RIPDIE  
0
4
RSPDIE  
0
3
RLPDIE  
0
2
REPCIE  
0
1
RAPCIE  
0
0
RSPCIE  
0
Bit 7 : Receive FCS Errored Packet Interrupt Enable (REPIE) – This bit enables an interrupt if the REPL bit in  
the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 6 : Receive Aborted Packet Interrupt Enable (RAPIE) – This bit enables an interrupt if the RAPL bit in the  
RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 5 : Receive Invalid Packet Detected Interrupt Enable (RIPDIE) – This bit enables an interrupt if the RIPDL  
bit in the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 4 : Receive Small Packet Detected Interrupt Enable (RSPDIE) – This bit enables an interrupt if the RSPDL  
bit in the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 3 : Receive Large Packet Detected Interrupt Enable (RLPDIE) – This bit enables an interrupt if the RLPDL  
bit in the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 2 : Receive FCS Errored Packet Count Interrupt Enable (REPCIE) – This bit enables an interrupt if the  
REPCL bit in the RPPSRL register is set. Must be set low when the packets do not have an FCS appended.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 1 : Receive Aborted Packet Count Interrupt Enable (RAPCIE) – This bit enables an interrupt if the RAPCL  
bit in the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 0 : Receive Size Violation Packet Count Interrupt Enable (RSPCIE) – This bit enables an interrupt if the  
RSPCL bit in the RPPSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
156 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Packet Count (RPC[23:0]) – These twenty-four bits indicate the number of packets stored in the receive  
FIFO without an abort indication. Note: Packets discarded due to system loopback or an overflow condition will be  
included in this count.  
Register Name:  
Register Description:  
Address (hex):  
RPCR1  
Receive Packet Count Register 1  
1014, 1214, 1414, 1614  
Bit #  
Name  
Default  
7
RPC7  
0
6
RPC6  
0
5
RPC5  
0
4
RPC4  
0
3
RPC3  
0
2
RPC2  
0
1
RPC1  
0
0
RPC0  
0
Bits 7 to 0 : Receive Packet Count (RPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RPCR2  
Receive Packet Count Register 2  
1015, 1215, 1415, 1615  
Bit #  
Name  
Default  
7
RPC15  
0
6
RPC14  
0
5
RPC13  
0
4
RPC12  
0
3
RPC11  
0
2
RPC10  
0
1
RPC9  
0
0
RPC8  
0
Bits 7 to 0 : Receive Packet Count (RPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RPCR3  
Receive Packet Count Register 3  
1016, 1216, 1416, 1616  
Bit #  
Name  
Default  
7
RPC23  
0
6
RPC22  
0
5
RPC21  
0
4
RPC20  
0
3
RPC19  
0
2
RPC18  
0
1
RPC17  
0
0
RPC16  
0
Bits 7 to 0 : Receive Packet Count (RPC[23:16])  
157 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive FCS Errored Packet Count (RFPC[23:0]) – These twenty-four bits indicate the number of packets  
received with an FCS error. The byte count for these packets is included in the receive aborted byte count register  
REBCR.  
Register Name:  
Register Description:  
Address (hex):  
RFPCR1  
Receive FCS Errored Packet Count Register 1  
1018, 1218, 1418, 1618  
Bit #  
Name  
Default  
7
RFPC7  
0
6
RFPC6  
0
5
RFPC5  
0
4
RFPC4  
0
3
RFPC3  
0
2
RFPC2  
0
1
RFPC1  
0
0
RFPC0  
0
Bits 7 to 0 : Receive FCS Errored Packet Count (RFPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RFPCR2  
Receive FCS Errored Packet Count Register 2  
1019, 1219, 1419, 1619  
Bit #  
Name  
Default  
7
RFPC15  
0
6
RFPC14  
0
5
RFPC13  
0
4
RFPC12  
0
3
RFPC11  
0
2
RFPC10  
0
1
RFPC9  
0
0
RFPC8  
0
Bits 7 to 0 : Receive FCS Errored Packet Count (RFPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RFPCR3  
Receive FCS Errored Packet Count Register 3  
1020, 1220, 1420, 1620  
Bit #  
Name  
Default  
7
RFPC23  
0
6
RFPC22  
0
5
RFPC21  
0
4
RFPC20  
0
3
RFPC19  
0
2
RFPC18  
0
1
RFPC17  
0
0
RFPC16  
0
Bits 7 to 0 : Receive FCS Errored Packet Count (RFPC[23:16])  
158 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Aborted Packet Count (RAPC[23:0]) – These twenty-four bits indicate the number of packets received  
with a packet abort indication. The byte count for these packets is included in the receive aborted byte count  
register REBCR.  
Register Name:  
Register Description:  
Address (hex):  
RAPCR1  
Receive Aborted Packet Count Register 1  
101C, 121C, 141C, 161C  
Bit #  
Name  
Default  
7
RAPC7  
0
6
RAPC6  
0
5
RAPC5  
0
4
RAPC4  
0
3
RAPC3  
0
2
RAPC2  
0
1
RAPC1  
0
0
RAPC0  
0
Bits 7 to 0 : Receive Aborted Packet Count (RAPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RAPCR2  
Receive Aborted Packet Count Register 2  
101D, 121D, 141D, 161D  
Bit #  
Name  
Default  
7
RAPC15  
0
6
RAPC14  
0
5
RAPC13  
0
4
RAPC12  
0
3
RAPC11  
0
2
RAPC10  
0
1
RAPC9  
0
0
RAPC8  
0
Bits 7 to 0 : Receive Aborted Packet Count (RAPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RAPCR3  
Receive Aborted Packet Count Register 3  
101E, 121E, 141E, 161E  
Bit #  
Name  
Default  
7
RAPC23  
0
6
RAPC22  
0
5
RAPC21  
0
4
RAPC20  
0
3
RAPC19  
0
2
RAPC18  
0
1
RAPC17  
0
0
RAPC16  
0
Bits 7 to 0 : Receive Aborted Packet Count (RAPC[23:16])  
159 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Size Violation Packet Count (RSPC[23:0]) – These twenty-four bits indicate the number of packets  
received with a packet size violation (below minimum, above maximum, or non-integer number of bytes). The byte  
count for these packets is included in the receive aborted byte count register REBCR.  
Register Name:  
Register Description:  
Address (hex):  
RSPCR1  
Receive Size Violation Packet Count Register 1  
1020, 1220, 1420, 1620  
Bit #  
Name  
Default  
7
RSPC7  
0
6
RSPC6  
0
5
RSPC5  
0
4
RSPC4  
0
3
RSPC3  
0
2
RSPC2  
0
1
RSPC1  
0
0
RSPC0  
0
Bits 7 to 0 : Receive Size Violation Packet Count (RSPC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RSPCR2  
Receive Size Violation Packet Count Register 2  
1021, 1221, 1421, 1621  
Bit #  
Name  
Default  
7
RSPC15  
0
6
RSPC14  
0
5
RSPC13  
0
4
RSPC12  
0
3
RSPC11  
0
2
RSPC10  
0
1
RSPC9  
0
0
RSPC8  
0
Bits 7 to 0 : Receive Size Violation Packet Count (RSPC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RSPCR3  
Receive Size Violation Packet Count Register 3  
1022, 1222, 1422, 1622  
Bit #  
Name  
Default  
7
RSPC23  
0
6
RSPC22  
0
5
RSPC21  
0
4
RSPC20  
0
3
RSPC19  
0
2
RSPC18  
0
1
RSPC17  
0
0
RSPC16  
0
Bits 7 to 0 : Receive Size Violation Packet Count (RSPC[23:16])  
160 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Byte Count (RBC[31:0]) – These thirty-two bits indicate the number of bytes contained in packets stored  
in the receive FIFO without an abort indication. Note: Bytes discarded due to FCS extraction, system loopback,  
FIFO reset, or an overflow condition may be included in this count.  
Register Name:  
Register Description:  
Address (hex):  
RBCR1  
Receive Byte Count Register 1  
1028, 1228, 1428, 1628  
Bit #  
Name  
Default  
7
RBC7  
0
6
RBC6  
0
5
RBC5  
0
4
RBC4  
0
3
RBC3  
0
2
RBC2  
0
1
RBC1  
0
0
RBC0  
0
Bits 7 to 0 : Receive Byte Count (RBC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RBCR2  
Receive Byte Count Register 2  
1029, 1229, 1429, 1629  
Bit #  
Name  
Default  
7
RBC15  
0
6
RBC14  
0
5
RBC13  
0
4
RBC12  
0
3
RBC11  
0
2
RBC10  
0
1
RBC9  
0
0
RBC8  
0
Bits 7 to 0 : Receive Byte Count (RBC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RBCR3  
Receive Byte Count Register 3  
102A, 122A, 142A, 162A  
Bit #  
Name  
Default  
7
RBC23  
0
6
RBC22  
0
5
RBC21  
0
4
RBC20  
0
3
RBC19  
0
2
RBC18  
0
1
RBC17  
0
0
RBC16  
0
Bits 7 to 0 : Receive Byte Count (RBC[23:16])  
Register Name:  
Register Description:  
Address (hex):  
RBCR4  
Receive Byte Count Register 4  
102B, 122B, 142B, 162B  
Bit #  
Name  
Default  
7
RBC31  
0
6
RBC30  
0
5
RBC29  
0
4
RBC28  
0
3
RBC27  
0
2
RBC26  
0
1
RBC25  
0
0
RBC24  
0
Bits 7 to 0 : Receive Byte Count (RBC[31:24])  
161 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Receive Aborted Byte Count (RABC[31:0]) – These thirty-two bits indicate the number of bytes contained in  
packets stored in the receive FIFO with an abort indication. Note: Bytes discarded due to FCS extraction, system  
loopback, FIFO reset, or an overflow condition may be included in this count.  
Register Name:  
Register Description:  
Address (hex):  
RABCR1  
Receive Aborted Byte Count Register 1  
102C, 122C, 142C, 162C  
Bit #  
Name  
Default  
7
RABC7  
0
6
RABC6  
0
5
RABC5  
0
4
RABC4  
0
3
RABC3  
0
2
RABC2  
0
1
RABC1  
0
0
RABC0  
0
Bits 7 to 0 : Receive Aborted Byte Count (RABC[7:0])  
Register Name:  
Register Description:  
Address (hex):  
RABCR2  
Receive Aborted Byte Count Register 2  
102D, 122D, 142D, 162D  
Bit #  
Name  
Default  
7
RABC15  
0
6
RABC14  
0
5
RABC13  
0
4
RABC12  
0
3
RABC11  
0
2
RABC10  
0
1
RABC9  
0
0
RABC8  
0
Bits 7 to 0 : Receive Aborted Byte Count (RABC[15:8])  
Register Name:  
Register Description:  
Address (hex):  
RABCR3  
Receive Aborted Byte Count Register 3  
102E, 122E, 142E, 162E  
Bit #  
Name  
Default  
7
RABC23  
0
6
RABC22  
0
5
RABC21  
0
4
RABC20  
0
3
RABC19  
0
2
RABC18  
0
1
RABC17  
0
0
RABC16  
0
Bits 7 to 0 : Receive Aborted Byte Count (RABC[23:16])  
Register Name:  
Register Description:  
Address (hex):  
RABCR4  
Receive Aborted Byte Count Register 4  
102F, 122F, 142F, 162F  
Bit #  
Name  
Default  
7
RABC31  
0
6
RABC30  
0
5
RABC29  
0
4
RABC28  
0
3
RABC27  
0
2
RABC26  
0
1
RABC25  
0
0
RABC24  
0
Bits 7 to 0 : Receive Aborted Byte Count (RABC[31:24])  
162 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.2.8 Receive FIFO Registers  
Table 11-7 Receive FIFO Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
1080  
NAME  
FUNCTION  
RFC  
Receive FIFO Control Register  
1081  
1082  
-
Unused. Must be set = 0 for proper operation.  
Receive FIFO Level Control Register 1  
RFLC1  
1083  
RFLC2  
Receive FIFO Level Control Register 2  
1084  
1085  
1086  
1087  
RFPAC  
Receive FIFO Port Address Control Register  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Receive FIFO Status Register Latched  
-
-
-
1088  
RFSRL  
1089  
108A  
108B-108F  
-
Unused. Must be set = 0 for proper operation.  
Receive FIFO Status Register Interrupt Enable  
Unused. Must be set = 0 for proper operation.  
RFSRIE  
-
Register Name:  
RFC  
Register Description:  
Address (hex):  
Receive FIFO Control Register  
1080, 1280, 1480, 1680  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
RFRST  
1
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Receive FIFO Reset (RFRST) – When 0, the Receive FIFO will resume normal operations, however, data  
is discarded until a start of packet/cell is received after RAM power-up is completed. When 1, the Receive FIFO is  
emptied, any transfer in progress is halted, the FIFO RAM is powered down, the associated RDXA signal is forced  
low, and all incoming data is discarded. If the port was selected when the reset was initiated, the port will be  
deselected, and must be reselected (REN deasserted with address on RADR or RSX asserted with address on  
RDAT) before any transfer will occur.  
163 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RFLC1  
Receive FIFO Level Control Register 1  
1082, 1282, 1482, 1682  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
RFAF5  
0
4
RFAF4  
1
3
RFAF3  
0
2
RFAF2  
0
1
RFAF1  
0
0
RFAF0  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 0 : Receive FIFO Almost Full Level (RFAF[5:0]) – In POS-PHY packet processing mode, these six bits  
indicate the maximum number of four byte groups that can be available in the Receive FIFO for it to be considered  
"almost full". E.g., a value of 30 (1Eh) results in the FIFO being "almost full" when it has 120 (78h) bytes or less  
available. In cell processing mode, these bits are ignored.  
Register Name:  
Register Description:  
Address (hex):  
RFLC2  
Receive FIFO Level Control Register 2  
1083, 1283, 1483, 1683  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
RFAE5  
0
4
RFAE4  
1
3
RFAE3  
0
2
RFAE2  
0
1
RFAE1  
0
0
RFAE0  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 0 : Receive FIFO Almost Empty Level (RFAE[5:0]) – In POS-PHY packet processing mode, these six  
bits indicate the maximum number of four byte groups that can be stored in the Receive FIFO for it to be  
considered "almost empty". E.g., a value of 30 (1Eh) results in the FIFO being "almost empty" when it contains 120  
(78h) bytes or less. In cell processing mode, RFAE[5:2] are ignored, and RFAE[1:0] indicate the maximum number  
of cells that can be stored in the Receive FIFO for it to be considered "almost empty".  
164 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RFPAC  
Receive FIFO Port Address Control Register  
1084, 1284, 1484, 1684  
Bit #  
Name  
Default  
7
RPA7  
0
6
RPA6  
0
5
RPA5  
0
4
RPA4  
0
3
RPA3  
0
2
RPA2  
0
1
RPA1  
0
0
RPA0  
0
Bits 7 to 0 : Receive FIFO System Port Address (RPA[7:0]) – These eight bits set the Receive FIFO system  
interface port address used to poll the Receive FIFO for fill status, and select it for data transfer. Each port in the  
device must have a different port address. In Level II mode, bits RPA[7:5] are ignored, and if bits RPA[4:0] are set  
to a value of 1Fh, the port is disabled.  
Register Name:  
Register Description:  
Address (hex):  
RFSRL  
Receive FIFO Status Register Latched  
1088, 1288, 1488, 1688  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
RFOL  
0
Bits 7 to 1 : Unused  
Bit 0 : Receive FIFO Overflow Latched (RFOL) – This bit is cleared when a logic one is written to this bit, and set  
when a Receive FIFO overflow condition occurs. An overflow condition results in a loss of data.  
Register Name:  
Register Description:  
Address (hex):  
RFSRIE  
Receive FIFO Status Register Interrupt Enable  
108A, 128A, 148A, 168A  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
RFOIE  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Receive FIFO Overflow Interrupt Enable (RFOIE) – This bit enables an interrupt if the RFOL bit in the  
RFSRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
165 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.3 System Interface Registers  
11.3.1 Transmit System Interface Registers  
Table 11-8 Transmit System Interface Register Map  
ADDRESS (hex)  
1940  
NAME  
TSIC1  
TSIC2  
TSISRL  
-
FUNCTION  
Transmit System Interface Control Register 1  
Transmit System Interface Control Register 2  
Transmit System Interface Status Register Latched  
Unused. Must be set = 0 for proper operation.  
Transmit System Interface Status Register Interrupt Enable  
Unused. Must be set = 0 for proper operation.  
1941  
1942  
1943  
1944  
TSISRIE  
-
1945 – 194F  
Register Name:  
TSIC1  
Register Description:  
Address (hex):  
Transmit System Interface Control Register 1  
1940  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
TPARP  
0
2
TFLVI  
0
1
TSBRE  
0
0
THECT  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit System Parity Polarity (TPARP) – When 0, the TPAR signal will maintain odd parity (for all 0''s,  
TPAR is high). When 1, the TPAR signal will maintain even parity (for all 0''s, TPAR is low).  
Bit 2 : Transmit System Fill Level Inversion (TFLVI) – When 0, the polarity of the TPXA, TDXA, and TSPA  
signals will be normal (high for data available). When 1, the polarity of the TPXA, TDXA, and TSPA signals will be  
inverted (low for data available).  
Bit 1 : Transmit System Interface Byte Reordering Enable (TSBRE) – When 0, byte reordering is disabled, and  
the first byte transmitted is transferred across the system interface as the most significant byte (TDAT[15:8] in 16-  
bit mode). When 1, byte reordering is enabled, and the first byte transmitted is transferred across the system  
interface as the least significant byte (TDAT[7:0]).  
Bit 0 : Transmit System HEC Transfer (THECT) – When 0, The HEC byte is not transferred across the transmit  
system interface. When 1, the HEC byte is transferred across the transmit system interface with the cell data.  
166 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSIC2  
Transmit System Interface Control Register 2  
1941  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TXAD5  
0
4
TXAD4  
0
3
TXAD3  
0
2
TXAD2  
0
1
TXAD1  
0
0
TXAD0  
0
Bits 7 to 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 0 : Transmit Cell/Packet Available Deassertion Time (TXAD[5:0]) – These six bits indicate the amount  
of data that can be transferred after the cell/packet available signal is deasserted. If more than the indicated  
amount of data is transferred, a Transmit FIFO overflow may occur.  
In UTOPIA mode, only TXAD[2:0] are valid, and they indicate the number of transfers before the Transmit FIFO is  
full. For UTOPIA Level 2, a value of 00h enables the default mode, which is 5. (TDXA will transition low on the  
edge that samples payload byte 43 in 8-bit mode, payload bytes 37 and 38 in 16-bit mode.) For UTOPIA Level 3, a  
value of 00h or 01h enables the default mode. The default for UTOPIA Level 3 is for TDXA to transition low on the  
clock edge following the edge that samples the start of a cell.  
In POS-PHY mode, TXAD[5:0] indicate the number of 4-byte data groups that can be written into the Transmit  
FIFO before it is full (maximum value 56 or 38h). In POS-PHY Level 2, a value of 00h enables the default mode,  
which is 1. (For an x-byte transfer, TDXA and TSPA will transition low on the edge that samples byte x-4 in 8-bit  
mode, bytes x-5 and x-4 in 16-bit mode.) In POS-PHY Level 3 (8-bit), a value of 00h enables the default mode,  
which is 1. (For an x-byte transfer, TDXA and TSPA will transition low on the edge that samples byte x-4). For  
POS-PHY Level 3 (16-bit), a value of 00h or 01h enables the default mode, which is 2. (For an x-byte transfer,  
TDXA and TSPA will transition low on the edge that samples bytes x-9 and x-8.) Note: A packet that is 4x+1, 4x+2,  
4x+3, or 4x+4 (where x is an integer) bytes long consumes x+1 four byte data groups of space in the FIFO. This  
includes 2-byte and 3-byte packets, which consume a 4-byte data group of space in the FIFO.  
167 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSISRL  
Transmit System Interface Status Register Latched  
1942  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
TCLKAL  
0
0
TPREL  
0
Bits 7 to 2 : Unused.  
Bit 1 : Transmit System Interface Clock Active (TCLKAL) – This bit is set when TSCLK samples the associated  
transmit system interface inputs.  
Bit 0 : Transmit System Interface Parity Error Latched (TPREL) – This bit is set when a parity error is detected  
during a data transfer on the Transmit System Interface bus.  
Register Name:  
Register Description:  
Address (hex):  
TSISRIE  
Transmit System Interface Status Register Interrupt Enable  
1944  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
TPREIE  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit System Interface Parity Error Interrupt Enable (TPREIE) – This bit enables an interrupt if the  
TPREL bit in the TSISRL register is set.  
0 = interrupt disabled  
1 = interrupt enabled  
11.3.2 Receive System Interface Registers  
Table 11-9 Receive System Interface Register Map  
Address (hex)  
1900  
NAME  
RSIC1  
RSIC2  
RSIC3  
RSIC4  
RSISRL  
-
FUNCTION  
Receive System Interface Control Register 1  
Receive System Interface Control Register 2  
Receive System Interface Control Register 3  
Receive System Interface Control Register 4  
Receive System Interface Status Register Latched  
Unused. Must be set = 0 for proper operation.  
1901  
1902  
1903  
1904  
1905-190F  
168 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.3.2.1 Register Bit Descriptions  
Register Name:  
Register Description:  
Address (hex):  
RSIC1  
Receive System Interface Control Register 1  
1900  
Bit #  
Name  
Default  
7
--  
0
6
RXAD2  
0
5
RXAD1  
0
4
RXAD0  
0
3
RPARP  
0
2
RFLVI  
0
1
RSBRE  
0
0
RHECT  
0
Bit 7 : Unused. Must be set = 0 for proper operation.  
Bits 6 to 4 : Receive Cell Available Deassertion Time (RXAD[2:0]) – These three bits indicate the number of  
transfers that will occur after the selected Receive FIFO indicates it is "empty". A value of 000, enables the default  
mode. The default for UTOPIA Level 2 is 0 (RDXA will transition low on the clock edge following the clock edge  
that outputs payload byte 48 in 8-bit mode, payload bytes 47 and 48 in 16-bit mode). The default for UTOPIA Level  
3 is for RDXA to transition low on the clock edge that outputs the start of cell. These bits are ignored in POS-PHY  
mode.  
Bit 3 : Receive System Parity Polarity (RPARP) – When 0, the RPAR signal will maintain odd parity (for all 0''s,  
RPAR is high). When 1, the RPAR signal will maintain even parity (for all 0''s, RPAR is low).  
Bit 2 : Receive System Fill Level Inversion (RFLVI) – When 0, the polarity of the RPXA and RDXA signals will  
be normal (high for data available). When 1, the polarity of the RPXA and RDXA signals will be inverted (low for  
data available).  
Bit 1 : Receive System Interface Byte Reordering Enable (RSBRE) – When 0, byte reordering is disabled, and  
the first byte received is transferred across the system interface as the most significant byte (RDAT[15:8] in 16-bit  
mode). When 1, byte reordering is enabled, and the first byte received is transferred across the system interface as  
the least significant byte (RDAT[7:0]).  
Bit 0 : Receive System HEC Transfer Enable (RHECT) – When 0, The HEC byte is not transferred across the  
receive system interface. When 1, the HEC byte is transferred across the receive system interface with the cell  
data.  
Register Name:  
Register Description:  
Address (hex):  
RSIC2  
Receive System Interface Control Register 2  
1901  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
RMDT2  
0
1
RMDT1  
0
0
RMDT0  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 to 0 : Receive System RVAL Minimum Deassertion Time (RMDT[2:0]) – These three bits indicate the  
minimum number of clock cycles that RVAL must remain deasserted between packets transferred from the same  
port, a transfer of data equal to the maximum burst length (if enabled), or before RSX can be asserted. A value of  
zero, means that RVAL will not deassert between packets transferred from the same port or between transfers of  
the maximum burst length when no other port has data available. These bits are ignored in UTOPIA and POS-PHY  
Level II modes. Note: The RVAL minimum deassertion time is for optionally extending the time between packet  
transfers and port changes to allow a POS-PHY Level 3 Link Layer device enough time to deassert REN and  
pause the next data transfer.  
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Register Name:  
Register Description:  
Address (hex):  
RSIC3  
Receive System Interface Control Register 3  
1902  
Bit #  
Name  
Default  
7
RLBL7  
0
6
RLBL6  
0
5
RLBL5  
0
4
RLBL4  
0
3
RLBL3  
0
2
RLBL2  
0
1
RLBL1  
0
0
RLBL0  
0
Bits 7 to 0 : Receive System Loopback Bandwidth Limit (RLBL[7:0]) – These eight bits limit the maximum  
bandwidth of a single port during system loopback. For RLBL[7:0] equals x the bandwidth will be limited to 1/x of  
the maximum system interface bandwidth. In 8-bit and 16-bit mode, a value of 00h is treated as 01h.  
Register Name:  
Register Description:  
Address (hex):  
RSIC4  
Receive System Interface Control Register 4  
1903  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
RMBL5  
0
4
RMBL4  
0
3
RMBL3  
0
2
RMBL2  
0
1
RMBL1  
0
0
RMBL0  
0
Bits 7to 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 to 0 : Receive Maximum Burst Length (RMBL[5:0]) – In POS-PHY Level 3, these six bits limit the  
maximum number of four byte data groups that can be transferred from a port before switching to another port. The  
maximum number of transfers is 2*(RMBL[5:0]+1} in 16-bit mode, and 4*(RMBL[5:0]+1} in 8-bit mode. Note: if no  
other port is ready to start a transfer, transfer from the current port will continue if the port contains more data than  
the almost empty level or contains an end of packet. These bits are ignored in POS-PHY Level 2 or UTOPIA mode.  
A value of 00h disables the maximum burst length.  
Register Name:  
Register Description:  
Address (hex):  
RSISRL  
Receive System Interface Status Register Latched  
1904  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
--  
0
2
--  
0
1
--  
0
0
RCLKAL  
0
Bits 7 to 1 : Unused.  
Bit 0 : Receive System Interface Clock Active Latched (RCLKAL) – This bit is set when RCLK samples the  
associated receive system interface inputs.  
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11.4 Receive T1 Framer Registers  
Table 11-10 T1 Receive Framer Register Map  
ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0000-00F  
0010  
NAME  
FUNCTION  
RHC  
Unused. Must be set = 0 for proper operation.  
Rx HDLC Control  
0011  
0012  
0013  
0014  
RHBSE  
RDS0SEL  
RSIGC  
RCR2  
Rx HDLC Bit Suppress  
Rx DS0 Monitor Select  
Rx Signaling Control  
Rx Control 2  
0015  
0016 – 001F  
0020  
RBOCC  
Rx BOC Control  
Unused. Must be set = 0 for proper operation.  
Rx Idle Definition 1  
RIDR1  
RIDR2  
RIDR3  
RIDR4  
RIDR5  
RIDR6  
RIDR7  
RIDR8  
RIDR9  
RIDR10  
RIDR11  
RIDR12  
RIDR13  
RIDR14  
RIDR15  
RIDR16  
RIDR17  
RIDR18  
RIDR19  
RIDR20  
RIDR21  
RIDR22  
RIDR23  
RIDR24  
RSAOI1  
RSAOI2  
RSAOI3  
0021  
0022  
0023  
0024  
0025  
0026  
0027  
0028  
0029  
002A  
002B  
002C  
002D  
002E  
002F  
0030  
0031  
0032  
0033  
0034  
0035  
0036  
0037  
0038  
0039  
003A  
003B  
003C  
003D  
003E  
003F  
0040  
Rx Idle Definition 2  
Rx Idle Definition 3  
Rx Idle Definition 4  
Rx Idle Definition 5  
Rx Idle Definition 6  
Rx Idle Definition 7  
Rx Idle Definition 8  
Rx Idle Definition 9  
Rx Idle Definition 10  
Rx Idle Definition 11  
Rx Idle Definition 12  
Rx Idle Definition 13  
Rx Idle Definition 14  
Rx Idle Definition 15  
Rx Idle Definition 16  
Rx Idle Definition 17  
Rx Idle Definition 18  
Rx Idle Definition 19  
Rx Idle Definition 20  
Rx Idle Definition 21  
Rx Idle Definition 22  
Rx Idle Definition 23  
Rx Idle Definition 24  
Rx Sig All Ones Insertion 1  
Rx Sig All Ones Insertion 2  
Rx Sig All Ones Insertion 3  
Unused. Must be set = 0 for proper operation.  
Rx Digital Milliwatt Enable 1  
Rx Digital Milliwatt Enable 2  
Rx Digital Milliwatt Enable 3  
Unused. Must be set = 0 for proper operation.  
Rx Signaling 1  
RDMWE1  
RDMWE2  
RDMWE3  
RS1  
0041  
RS2  
Rx Signaling 2  
0042  
RS3  
Rx Signaling 3  
0043  
RS4  
Rx Signaling 4  
0044  
RS5  
Rx Signaling 5  
0045  
RS6  
Rx Signaling 6  
0046  
RS7  
Rx Signaling 7  
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ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0047  
NAME  
FUNCTION  
RS8  
RS9  
RS10  
RS11  
RS12  
LCVCR1  
LCVCR2  
PCVCR1  
PCVCR2  
FOSCR1  
FOSCR2  
Rx Signaling 8  
Rx Signaling 9  
Rx Signaling 10  
Rx Signaling 11  
Rx Signaling 12  
0048  
0049  
004A  
004B  
004C – 004F  
0050  
Unused. Must be set = 0 for proper operation.  
Rx Line-Code Violation Counter 1  
Rx Line-Code Violation Counter 2  
Rx Path-Code Violation Count 1  
Rx Path-Code Violation Count 2  
Rx Frames Out-of-Sync Counter 1  
Rx Frames Out-of-Sync Counter 2  
Unused. Must be set = 0 for proper operation.  
Rx DS0 Monitor  
0051  
0052  
0053  
0054  
0055  
0056-005F  
0060  
RDS0M  
0061  
0062  
0063  
0064  
0065  
0066  
Unused. Must be set = 0 for proper operation.  
Rx FDL  
RFDL  
RBOC  
RSLC1  
RSLC2  
RSLC3  
RMMR  
RCR1  
RIBCC  
RCR3  
RIOCR  
RGCCR  
ERCNT  
RHFC  
-
RSCC  
RBICR  
RBBS  
RLS1  
RLS2  
RLS3  
RLS4  
RLS5  
Rx BOC  
Rx SLC96 Data Link 1  
Rx SLC96 Data Link 2  
Rx SLC96 Data Link 3  
0067-007F  
0080  
Unused. Must be set = 0 for proper operation.  
Rx Master Mode  
0081  
0082  
0083  
0084  
0085  
0086  
0087  
0088  
Rx Control 1  
Rx In-Band Code Control  
Rx Control 3  
Rx I/O Configuration  
Rx Gapped Clock Control  
Rx Error Count Configuration  
Rx HDLC FIFO Control  
Unused. Must be set = 0 for proper operation.  
Rx Spare Code Control  
Rx BERT Interface Control  
Rx BERT Bit Suppress En  
0089  
008A  
008B  
008C – 008F  
0090  
Unused. Must be set = 0 for proper operation.  
Rx Latched Status 1  
0091  
0092  
0093  
0094  
0095  
0096  
0097  
0098  
0099  
009A  
009B  
009C  
009D  
009E  
009F  
00A0  
Rx Latched Status 2  
Rx Latched Status 3  
Rx Latched Status 4  
Rx Latched Status 5  
Unused. Must be set = 0 for proper operation.  
Rx Latched Status 7  
RLS7  
RSS1  
RSS2  
RSS3  
RSCD1  
RSCD2  
Unused. Must be set = 0 for proper operation.  
Rx Signaling CoS Status 1  
Rx Signaling CoS Status 2  
Rx Signaling CoS Status 3  
Unused. Must be set = 0 for proper operation.  
Rx Spare Code Definition 1  
Rx Spare Code Definition 2  
Unused. Must be set = 0 for proper operation.  
Rx Interrupt Information Reg  
Rx Interrupt Mask Reg 1  
RIIR  
RIM1  
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ADDRESS (hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
00A1  
NAME  
FUNCTION  
Unused. Must be set = 0 for proper operation.  
00A2  
RIM3  
Rx Interrupt Mask Reg 3  
00A3  
RIM4  
Rx Interrupt Mask Reg 4  
00A4  
RIM5  
Rx Interrupt Mask Reg 5  
00A5  
00A6  
RIM7  
Unused. Must be set = 0 for proper operation.  
Rx Interrupt Mask Reg 7  
00A7  
00A8  
00A9  
00AA  
00AB  
00AC  
00AD  
00AE  
00AF  
00B0  
00B1  
00B2  
00B3  
00B4  
00B5  
00B6  
Unused. Must be set = 0 for proper operation.  
Rx Sig CoS Interrupt Enable 1  
Rx Sig CoS Interrupt Enable 2  
Rx Sig CoS Interrupt Enable 3  
Unused. Must be set = 0 for proper operation.  
Rx Up-Code Definition 1  
Rx Up-Code Definition 2  
Rx Down-Code Definition 1  
Rx Down-Code Definition 2  
Rx Real-Time Status 1  
Unused. Must be set = 0 for proper operation.  
Rx Real-Time Status 3  
Unused. Must be set = 0 for proper operation.  
Rx Real-Time Status 5 (HDLC)  
Rx HDLC Packet Bytes Available  
Rx HDLC FIFO  
RSCSE1  
RSCSE2  
RSCSE3  
RUPCD1  
RUPCD2  
RDNCD1  
RDNCD2  
RRTS1  
RRTS3  
RRTS5  
RHPBA  
RHF  
00B7-00C3  
00C4  
Unused. Must be set = 0 for proper operation.  
Rx Channel Mark 1  
Rx Channel Mark 2  
Rx Channel Mark 3  
Rx Channel Mark 4  
RCMR1  
RCMR2  
RCMR3  
RCMR4  
RSI1  
00C5  
00C6  
00C7  
00C8  
Rx Signaling Insertion 1  
00C9  
RSI2  
Rx Signaling Insertion 2  
00CA  
RSI3  
Rx Signaling Insertion 3  
00CB  
RSI4  
Rx Signaling Insertion 4  
00CC  
00CD  
00CE  
00CF  
00D0  
00D1  
00D2  
00D3  
RGCCS1  
RGCCS2  
RGCCS3  
RGCCS4  
RCICE1  
RCICE2  
RCICE3  
RBCS1  
RBCS2  
RBCS3  
Rx Gapped Clock Channel Select 1  
Rx Gapped Clock Channel Select 2  
Rx Gapped Clock Channel Select 3  
Rx Gapped Clock Channel Select 4  
Rx Channel Idle Code Enable 1  
Rx Channel Idle Code Enable 2  
Rx Channel Idle Code Enable 3  
Unused. Must be set = 0 for proper operation.  
Rx BERT Channel Select 1  
00D4  
00D5  
00D6  
Rx BERT Channel Select 2  
Rx BERT Channel Select 3  
Unused. Must be set = 0 for proper operation.  
00D7 – 00DF  
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11.4.1 Receive Master-Mode Register  
The receive master-mode register (RMMR) controls the initialization of the receive-side framer. The FRM_EN bit  
can be left low if the framer for that particular port is not going to be used, putting the circuit in a low-power (sleep)  
state.  
Register Name:  
Register Description:  
Address (hex):  
RMMR  
Receive Master Mode Register  
0080, 0280, 0480, 0680  
Bit #  
Name  
Default  
7
6
5
0
4
0
3
0
2
0
1
SFTRST  
0
0
T1/E1  
0
FRM_EN INIT_DONE  
0
0
Bit 7 : Framer Enable (FRM_EN). This bit must be written with the desired value prior to setting INIT_DONE.  
0 = Framer disabled (held in low-power state)  
1 = Framer enabled (all features active)  
Bit 6 : Initialization Done (INIT_DONE). The host (user) must set this bit once the configuration registers have  
been written. The host is required to write or clear all RAM based registers (addresses 00H to 7FH) prior to setting  
this bit. Once INIT_DONE is set, the internal processor will check the FRM_EN bit. If enabled, the internal  
processor continues executing based on the initial configuration.  
Bits 5 to 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : Soft Reset (SFTRST) Level-sensitive processor reset. Should be taken high, then low to reset and initialize  
the internal processor.  
0 = Normal operation  
1 = Hold the internal RISC in reset. This bit only affects the receive-side processor.  
Bit 0 : Receiver T1/E1 Mode Select (T1/E1) This bit sets the operating mode for receiver only! This bit must be  
set to the desired state before writing INIT_DONE.  
0 = T1 operation  
1 = E1 operation  
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11.4.2 Interrupt Information Register  
The interrupt information registers provide an indication of which DS26556 status registers are generating an  
interrupt. When an interrupt occurs, the host can read RIIR to quickly identify which of the seven T1 receive status  
registers is causing the interrupt(s). The interrupt information register bits clear once the appropriate interrupt has  
been serviced and cleared, as long as no other interrupt condition is present in the associated status register.  
Status bits that have been masked through the receive-interrupt mask (RIMx) registers are also masked from the  
RIIR register.  
Register Name:  
Register Description:  
Address (hex):  
RIIR  
Receive Interrupt Information Register  
009F, 029F, 049F, 069F  
Bit #  
Name  
Default  
7
0
6
RLS7  
0
5
RLS6  
0
4
RLS5  
0
3
RLS4  
0
2
RLS3  
0
1
RLS2*  
0
0
RLS1  
0
*RLS2 does not create an interrupt, therefore this bit is not used in T1 mode.  
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11.4.3 T1 Receive Control Registers  
These registers provide the primary setup and control of the receive framers.  
Register Name:  
Register Description:  
Address (hex):  
RCR1  
Receive Control Register 1  
0081, 0281, 0481, 0681  
Bit #  
Name  
Default  
7
SYNCT  
0
6
RB8ZS  
0
5
RFM  
0
4
ARC  
0
3
SYNCC  
0
2
RJC  
0
1
0
SYNCE RESYNC  
0
0
Bit 7 : Sync Time (SYNCT)  
0 = qualify 10 bits  
1 = qualify 24 bits  
Bit 6 : Receive B8ZS Enable (RB8ZS)  
0 = B8ZS disabled  
1 = B8ZS enabled  
Bit 5 : Receive Frame Mode Select (RFM)  
0 = ESF framing mode  
1 = D4 framing mode  
Bit 4 : Auto Resync Criteria (ARC)  
0 = Resync on OOF or LOS event  
1 = Resync on OOF only  
Bit 3 : Sync Criteria (SYNCC)  
In D4 Framing Mode:  
0 = search for Ft pattern, then search for Fs pattern  
1 = cross couple Ft and Fs pattern  
In ESF Framing Mode:  
0 = search for FPS pattern only  
1 = search for FPS and verify with CRC6  
Bit 2 : Receive Japanese CRC6 Enable (RJC)  
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)  
1 = use Japanese standard JT-G704 CRC6 calculation  
Bit 1 : Sync Enable (SYNCE)  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 0 : Resynchronize (RESYNC). When toggled from low to high, a resynchronization of the receive-side framer  
is initiated. Must be cleared and set again for a subsequent resync.  
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Register Name:  
Register Description:  
Address (hex):  
RCR2  
Receive Control Register 2  
0014, 0214, 0414, 0614  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
RSLC96  
0
3
OOF2  
0
2
OOF1  
0
1
RAIIE  
0
0
RD4RM  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Receive SLC-96 Synchronizer Enable (RSLC96). See Section 11.4.13.  
0 = the SLC-96 synchronizer is disabled  
1 = the SLC-96 synchronizer is enable  
Bits 3, 2 : Out-of-Frame Select Bits (OOF2, OOF1)  
OOF2  
OOF1  
OUT OF FRAME CRITERIA  
2/4 frame bits in error  
2/5 frame bits in error  
2/6 frame bits in error  
2/6 frame bits in error  
0
0
1
1
0
1
0
1
Bit 1 : Receive RAI Integration Enable (RAIIE) The ESF RAI indication can be interrupted for a period not to  
exceed 100ms per interruption (T1.403). In ESF mode, setting RAIIE causes the RAI status from the DS26556 to  
be integrated for 200ms.  
0 = RAI detects when 16 consecutive patterns of 00FF appear in the FDL.  
RAI clears when 14 or less patterns of 00FF hex out of 16 possible appear in the FDL.  
1 = RAI detects when the condition has been present for greater than 200ms.  
RAI clears when the condition has been absent for greater than 200ms.  
Bit 0 : Receive-Side D4 Remote Alarm Select (RD4RM)  
0 = zeros in bit 2 of all channels  
1 = a one in the S-bit position of frame 12 (J1 Yellow Alarm Mode)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCR3  
Receive Control Register 3  
0083, 0283, 0483, 0683  
Bit #  
Name  
Default  
7
-
0
6
0
5
RSERC  
0
4
0
3
0
2
RLB  
0
1
PLB  
0
0
FLB  
0
Bits 7 & 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : RSER Control (RSERC)  
0 = Allow RSER to output data as received under all conditions (normal operation)  
1 = Force RSER to one under loss-of-frame alignment conditions  
Bits 4 & 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Remote Loopback (RLB)  
0 = loopback disabled  
1 = loopback enabled  
Bit 1 : Payload Loopback (PLB)  
0 = loopback disabled  
1 = loopback enabled  
Bit 0 : Framer Loopback (FLB)  
0 = loopback disabled  
1 = loopback enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIOCR  
Receive I/O Configuration Register  
0084, 0284, 0484, 0684  
Bit #  
7
6
5
4
3
2
1
0
Name  
RCLKIN RSYNCINV H100EN HSCLKM RSMS RSIO RSMS2 RSMS1  
V
Default  
0
0
0
0
0
0
0
0
Bit 7 : RCLK Invert (RCLKINV)  
0 = No inversion  
1 = Invert RCLK as input  
Bit 6 : RSYNC Invert (RSYNCINV)  
0 = No inversion  
1 = Invert RSYNC output  
Bit 5 : H.100 SYNC Mode (H100EN) See additional details in Section 8.4.2.  
0 = Normal operation  
1 = HSSYNC signals are shifted.  
Note: This bit setting must match TIOCR.HSCLKM  
Bit 4 : HSYSCLK Mode Select (HSCLKM)  
0 = if HSYSCLK is 1.544MHz  
1 = if HSYSCLK is 2.048MHz  
Note: This bit setting must match TIOCR.HSCLKM  
Bit 3 : RSYNC Multiframe Skip Control (RSMS) This bit is useful in framing format conversions from D4 to ESF.  
0 = RSYNC outputs a pulse at every multiframe.  
1 = RSYNC outputs a pulse at every other multiframe.  
Bit 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : RSYNC Mode Select 2 (RSMS2)  
T1: RSYNC pin must be programmed in the output frame mode  
0 = do not pulse double wide in signaling frames  
1 = do pulse double wide in signaling frames  
E1: RSYNC pin must be programmed in the output multiframe mode  
0 = RSYNC outputs CAS multiframe boundaries  
1 = RSYNC outputs CRC4 multiframe boundaries  
Bit 0 : RSYNC Mode Select 1 (RSMS1) Selects frame or multiframe pulse when RSYNC pin is in output mode.  
0 = frame mode  
1 = multiframe mode  
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Register Name:  
Register Description:  
Address (hex):  
RRTS1  
Receive Real-Time Status Register 1  
00B0, 02B0, 04B0, 06B0  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
RRAI  
0
2
RAIS  
0
1
RLOS  
0
0
RLOF  
0
All bits in this register are real-time (not latched).  
Bits 7 to 4 : Unused.  
Bit 3 : Receive Remote Alarm Indication Condition (RRAI) Set when a remote alarm is received at RPOS and  
RNEG.  
Bit 2 : Receive Alarm Indication Signal Condition (RAIS) Set when an unframed all-ones code is received at  
RPOS and RNEG.  
Bit 1 : Receive Loss-of-Signal Condition (RLOS) Set when 192 consecutive zeros have been detected at  
RPOS and RNEG.  
Bit 0 : Receive Loss-of-Frame Condition (RLOF) Set when the DS26556 is not synchronized to the received  
data stream.  
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Register Name:  
Register Description:  
Address (hex):  
RLS1  
Receive Latched Status Register 1  
0090, 0290, 0490, 0690  
Bit #  
Name  
Default  
7
RRAIC  
0
6
RAISC  
0
5
4
3
RRAID  
0
2
RAISD  
0
1
FLOSD  
0
0
RLOFD  
0
RLOSC RLOFC  
0
0
All bits in this register are latched and can create interrupts.  
Bit 7 : Receive Remote Alarm Indication Condition Clear (RRAIC) Falling edge detect of RRAI. Set when a  
RRAI condition has cleared.  
Bit 6 : Receive Alarm Indication Signal Condition Clear (RAISC) Falling edge detect of RAIS. Set when a RAIS  
condition has cleared.  
Bit 5 : Receive Loss-of-Signal Condition Clear (RLOSC) Falling edge detect of RLOS. Set when an RLOS  
condition has cleared.  
Bit 4 : Receive Loss-of-Frame Condition Clear (RLOFC) Falling edge detect of RLOF. Set when an RLOF  
condition has cleared.  
Bit 3 : Receive Remote Alarm Indication Condition Detect (RRAID) Rising edge detect of RRAI. Set when a  
remote alarm is received at RPOS and RNEG.  
Bit 2 : Receive Alarm Indication Signal Condition Detect (RAISD) Rising edge detect of RAIS. Set when an  
unframed all-ones code is received at RPOS and RNEG.  
Bit 1 : Receive Loss-of-Signal Condition Detect (RLOSD) Rising edge detect of RLOS. Set when 192  
consecutive zeros have been detected at RPOS and RNEG.  
Bit 0 : Receive Loss-of-Frame Condition Detect (RLOFD) Rising edge detect of RLOF. Set when the DS26556  
has lost synchronized to the received data stream.  
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Register Name:  
Register Description:  
Address (hex):  
RIM1  
Receive Interrupt Mask Register 1  
00A0, 02A0, 04A0, 06A0  
Bit #  
Name  
Default  
7
RRAIC  
0
6
RAISC  
0
5
4
3
RRAID  
0
2
RAISD  
0
1
0
RLOSC RLOFC  
RLOSD RLOFD  
0
0
0
0
Bit 7 : Receive Remote Alarm Indication Condition Clear (RRAIC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6 : Receive Alarm Indication Signal Condition Clear (RAISC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5 : Receive Loss-of-Signal Condition Clear (RLOSC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive Loss-of-Frame Condition Clear (RLOFC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Receive Remote Alarm Indication Condition Detect (RRAID)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive Alarm Indication Signal Condition Detect (RAISD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Receive Loss-of-Signal Condition Detect (RLOSD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Loss-of-Frame Condition Detect (RLOFD)  
0 = interrupt masked  
1 = interrupt enabled  
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Register Name:  
Register Description:  
Address (hex):  
RLS2  
Receive Latched Status Register 2  
0091, 0291, 0491, 0691  
Bit #  
Name  
Default  
7
RPDV  
0
6
0
5
COFA  
0
4
8ZD  
0
3
16ZD  
0
2
SEFE  
0
1
B8ZS  
0
0
FBE  
0
All bits in this register are latched. This register does not create interrupts.  
Bit 7 : Receive Pulse Density Violation Event (RPDV) Set when the receive data stream does not meet the  
ANSI T1.403 requirements for pulse density.  
Bit 6 : Unused.  
Bit 5 : Change-of-Frame Alignment Event (COFA) Set when the last resync resulted in a change of frame or  
multiframe alignment.  
Bit 4 : Eight Zero Detect Event (8ZD) Set when a string of at least eight consecutive zeros (regardless of the  
length of the string) have been received at RPOS and RNEG.  
Bit 3 : Sixteen Zero Detect Event (16ZD) Set when a string of at least 16 consecutive zeros (regardless of the  
length of the string) have been received at RPOS and RNEG.  
Bit 2 : Severely Errored Framing Event (SEFE) Set when 2 out of 6 framing bits (Ft or FPS) are received in  
error.  
Bit 1 : B8ZS Codeword Detect Event (B8ZS) Set when a B8ZS codeword is detected at RPOS and RNEG  
independent of whether the B8ZS mode is selected or not. This bit is useful for automatically setting the line  
coding.  
Bit 0 : Frame Bit Error Event (FBE) Set when an Ft (D4) or FPS (ESF) framing bit is received in error.  
Register Name:  
Register Description:  
Address (hex):  
RRTS3  
Receive Real-Time Status Register 3  
00B2, 02B2, 04B2, 06B2  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
LORC  
0
2
LSP  
0
1
LDN  
0
0
LUP  
0
All bits in this register are real-time (not latched).  
Bits 7 to 4 : Unused.  
Bit 3 : Loss-of-Receive Clock Condition (LORC) Set when the RCLK pin has not transitioned for one channel  
time.  
Bit 2 : Spare Code Detected Condition (LSP) Set when the spare code as defined in the RSCD1/2 registers is  
being received.  
Bit 1 : Loop-Down Code Detected Condition (LDN) Set when the loop-down code as defined in the RDNCD1/2  
register is being received.  
Bit 0 : Loop-Up Code Detected Condition (LUP) Set when the loop-up code as defined in the RUPCD1/2  
register is being received.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
184 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS3  
Receive Latched Status Register 3  
0092, 0292, 0492, 0692  
Bit #  
Name  
Default  
7
LORCC  
0
6
LSPC  
0
5
LDNC  
0
4
LUPC  
0
3
LORCD  
0
2
LSPD  
0
1
LDND  
0
0
LUPD  
0
All bits in this register are latched and can create interrupts.  
Bit 7 : Loss-of-Receive Clock Condition Clear (LORCC) Falling edge detect of LORC. Set when a LORC  
condition was detected and then removed.  
Bit 6 : Spare Code Detected Condition Clear (LSPC) Falling edge detect of LSP. Set when a spare-code match  
condition was detected and then removed.  
Bit 5 : Loop-Down Code Detected Condition Clear (LDNC) Falling edge detect of LDN. Set when a loop-down  
condition was detected and then removed.  
Bit 4 : Loop-Up Code Detected Condition Clear (LUPC) Falling edge detect of LUP. Set when a loop-up  
condition was detected and then removed.  
Bit 3 : Loss of Receive Clock Condition Detect (LORCD) Rising edge detect of LORC. Set when the RCLK pin  
has not transitioned for one channel time.  
Bit 2 : Spare Code Detected Condition Detect (LSPD) Rising edge detect of LSP. Set when the spare code as  
defined in the RSCD1/2 registers is being received.  
Bit 1 : Loop-Down Code Detected Condition Detect (LDND) Rising edge detect of LDN. Set when the loop-  
down code as defined in the RDNCD1/2 register is being received.  
Bit 0 : Loop-Up Code Detected Condition Detect (LUPD) Rising edge detect of LUP. Set when the loop-up  
code as defined in the RUPCD1/2 register is being received.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM3  
Receive Interrupt Mask Register 3  
00A2, 02A2, 04A2, 06A2  
Bit #  
Name  
Default  
7
LORCC  
0
6
LSPC  
0
5
LDNC  
0
4
LUPC  
0
3
LORCD  
0
2
LSPD  
0
1
LDND  
0
0
LUPD  
0
Bit 7 : Loss-of-Receive Clock Condition Clear (LORCC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6 : Spare Code Detected Condition Clear (LSPC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5 : Loop-Down Code Detected Condition Clear (LDNC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Loop-Up Code Detected Condition Clear (LUPC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Loss-of-Receive Clock Condition Detect (LORCD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Spare Code Detected Condition Detect (LSPD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Loop-Down Code Detected Condition Detect (LDND)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Loop-Up Code Detected Condition Detect (LUPD)  
0 = interrupt masked  
1 = interrupt enabled  
186 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS4  
Receive Latched Status Register 4  
0093, 0293, 0493, 0693  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
0
3
RSCOS  
0
2
1SEC  
0
1
TIMER  
0
0
RMF  
0
All bits in this register are latched and can create interrupts.  
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Receive Signaling Change-of-State Event (RSCOS) Set when any channel selected by the receive  
signaling change-of-state interrupt-enable registers (RSCSE1 through RSCSE3), changes signaling state.  
Bit 2 : One-Second Timer (1SEC) Set on every one-second interval based on RCLK.  
Bit 1 : Timer Event (TIMER) Follows the error counter update interval as determined by the ECUS bit in the error  
counter configuration register (ERCNT).  
T1: Set on increments of 1 second or 42ms based on RCLK.  
E1: Set on increments of 1 second or 62.5ms based on RCLK.  
Bit 0 : Receive Multiframe Event (RMF) Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF  
boundaries.  
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Register Name:  
Register Description:  
Address (hex):  
RIM4  
Receive Interrupt Mask Register 4  
00A3, 02A3, 04A3, 06A3  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
RSCOS  
0
2
1SEC  
0
1
TIMER  
0
0
RMF  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Receive Signaling Change-of-State Event (RSCOS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : One-Second Timer (1SEC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Timer Event (TIMER)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Multiframe Event (RMF)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS7  
Receive Latched Status Register 7  
0096, 0296, 0496, 0696  
Bit #  
Name  
Default  
7
0
6
0
5
4
3
2
1
BC  
0
0
BD  
0
RRAI-CI RAIS-CI RSLC96 RFDLF  
0
0
0
0
All bits in this register are latched and can create interrupts.  
Bits 6 & 7 : Unused.  
Bit 5 : Receive RAI-CI Detect (RRAI-CI) Set when an RAI-CI pattern has been detected by the receiver (see  
Section 11.5.1). This bit is active in ESF-framing mode only, and sets only if an RAI condition is being detected  
(RRTS1.3). When the host reads (and clears) this bit, it will set again each time the RAI-CI pattern is detected  
(approximately every 1.1 seconds).  
Bit 4 : Receive AIS-CI Detect (RAIS-CI) Set when an AIS-CI pattern has been detected by the receiver (see  
Section 11.5.1). This bit is set only if an AIS condition is being detected (RRTS1.2). This is a latched bit that must  
be cleared by the host, and sets again each time the AIS-CI pattern is detected (approximately every 1.2 seconds).  
Bit 3 : Receive SLC-96 Alignment Event (RSLC96) Set when a valid SLC-96 alignment pattern is detected in the  
fs-bit stream, and the RSLCx registers have data available for retrieval (Section 11.12).  
Bit 2 : Receive FDL Register Full Event (RFDLF) Set when the 8-bit RFDL register is full. Useful for SLC-96  
operation, or manual extraction of FDL data bits (Sections 11.12 and 11.13).  
Bit 1 : BOC Clear Event (BC) Set when a valid BOC is no longer detected (with the disintegration filter applied).  
(Section 11.11)  
Bit 0 : BOC Detect Event (BD) Set when a valid BOC has been detected (with the BOC filter applied)  
(Section 11.11)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM7  
Receive Interrupt Mask Register 7 (BOC/FDL)  
00A6, 02A6, 04A6, 06A6  
Bit #  
Name  
Default  
7
0
6
0
5
4
3
2
1
BC  
0
0
BD  
0
RRAI-CI RAIS-CI RSLC96 RFDLF  
0
0
0
0
Bits 6 & 7 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Receive RAI-CI (RRAI-CI)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive AIS-CI (RAIS-CI)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Receive SLC-96 (RSLC96)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive FDL Register Full (RFDLF)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : BOC Clear Event (BC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : BOC Detect Event (BD)  
0 = interrupt masked  
1 = interrupt enabled  
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Register Name:  
Register Description:  
Address (hex):  
RDMWE1  
T1 Receive-Digital Milliwatt-Enable Register 1  
003C, 023C, 043C, 063C  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
5
CH6  
4
CH5  
3
CH4  
2
CH3  
0
1
0
0
CH2  
CH1  
0
0
0
0
0
Bits 0 to 7 : Receive-Digital Milliwatt Enable for Channels 8 to 1 (CH8 to CH1)  
0 = Do not affect the receive data associated with this channel.  
1 = Replace the receive data associated with this channel with digital milliwatt code.  
Register Name:  
RDMWE2  
Register Description:  
Address (hex):  
T1 Receive-Digital Milliwatt-Enable Register 2  
003D, 023D, 043D, 063D  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 0 to 7 : Receive-Digital Milliwatt Enable for Channels 16 to 9 (CH16 to CH9)  
0 = Do not affect the receive data associated with this channel.  
1 = Replace the receive data associated with this channel with digital milliwatt code.  
Register Name:  
Register Description:  
Address (hex):  
RDMWE3  
T1 Receive-Digital Milliwatt-Enable Register 3  
003E, 023E, 043E, 063E  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 0 to 7 : Receive-Digital Milliwatt Enable for Channels 1 to 24 (CH24 to CH17)  
0 = Do not affect the receive data associated with this channel.  
1 = Replace the receive data associated with this channel with digital milliwatt code.  
191 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
ERCNT  
Error Counter Configuration Register  
0086, 0286, 0486, 0886  
Bit #  
Name  
Default  
7
1SECS  
0
6
MCUS  
0
5
MECU  
0
4
ECUS  
0
3
EAMS  
0
2
FSBE  
0
1
0
MOSCRF LCVCRF  
0
0
Bit 7 : One-Second Select (1SECS) When timed update is enabled by EAMS, setting this bit for a specific framer  
allows that framer’s counters to latch on the one-second reference from Framer #1.  
0 = Use internally generated one-second timer.  
1 = Use one-second timer from Framer #1.  
Bit 6 : Manual Counter Update Select (MCUS) When manual update mode is enabled with EAMS, this bit can  
be used to allow the GLCE bit in GCR1 to latch all counters. Useful for synchronously latching counters of multiple  
framers.  
0 = MECU is used to manually latch counters.  
1 = GLCE is used to manually latch counters.  
Bit 5 : Manual Error Counter Update (MECU) When enabled by ERCNT.3, the changing of this bit from 0 to 1  
allows the next clock cycle to load the error counter registers with the latest counts and reset the counters. The  
user must wait a minimum of 250μs before reading the error count registers to allow for proper update.  
Bit 4 : Error Counter Update Select (ECUS)  
T1 mode:  
0 = Update error counters once a second  
1 = Update error counters every 42ms (336 frames)  
E1 mode:  
0 = Update error counters once a second  
1 = Update error counters every 62.5ms (500 frames)  
Bit 3 : Error Accumulation Mode Select (EAMS)  
0 = ERCNT.4 determines accumulation time (timed update)  
1 = ERCNT.5 determines accumulation time (manual update)  
Bit 2 : PCVCR Fs-Bit Error Report Enable (FSBE)  
0 = do not report bit errors in Fs-bit position; only Ft bit position  
1 = report bit errors in Fs-bit position as well as Ft bit position  
Bit 1 : Multiframe Out-of-Sync Count Register Function Select (MOSCRF)  
0 = count errors in the framing bit position  
1 = count the number of out-of-sync multiframes  
Bit 0 : T1 Line-Code Violation Count Register Function Select (LCVCRF)  
0 = do not count excessive zeros  
1 = count excessive zeros  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.4 T1 Line-Code Violation Count Register (LCVCR)  
T1 code violations are defined as bipolar violations (BPVs) or excessive zeros. If the B8ZS mode is set for the  
receive side, then B8ZS codewords are not counted. This counter is always enabled; it is not disabled during  
receive loss-of-synchronization (RLOF = 1) conditions. See Table 11-11 for details of exactly what the LCVCRs  
count.  
Table 11-11 T1 Line-Code Violation Counting Options  
COUNT EXCESSIVE ZEROS?  
B8ZS ENABLED?  
WHAT IS COUNTED  
IN THE LCVCRs  
(ERCNT.0)  
(RCR1.6)  
No  
No  
BPVs  
Yes  
No  
Yes  
No  
Yes  
Yes  
BPVs + 16 consecutive zeros  
BPVs (B8ZS codewords not counted)  
BPVs + 8 consecutive zeros  
Register Name:  
Register Description:  
Address (hex):  
LCVCR1  
Line-Code Violation Count Register 1  
0050, 0250, 0450, 0650  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
LCCV8  
0
LCVC15 LCVC14 LCVC13 LCVC12 LCVC11 LCVC10 LCVC9  
0
0
0
0
0
0
0
Bits 7 to 0 : Line-Code Violation Counter Bits 15 to 8 (LCVC15 to LCVC8) LCV15 is the MSB of the 16-bit  
code violation count.  
Register Name:  
Register Description:  
Address (hex):  
LCVCR2  
Line-Code Violation Count Register 2  
0051, 0251, 0451, 0651  
Bit #  
Name  
Default  
7
LCVC7  
0
6
LCVC6  
0
5
LCVC5  
0
4
LCVC4  
0
3
2
1
LCVC1  
0
0
LCVC0  
0
LCVC3 LCVC2  
0
0
Bits 7 to 0 : Line-Code Violation Counter Bits 7 to 0 (LCVC7 to LCVC0) LCV0 is the LSB of the 16-bit code  
violation count  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.5 T1 Path-Code Violation Count Register (PCVCR)  
The path-code violation count register records either Ft, Fs, or CRC6 errors in T1 frames. When the receive side of  
a framer is set to operate in the T1 ESF framing mode, PCVCR records errors in the CRC6 codewords. When set  
to operate in the T1 D4 framing mode, PCVCR counts errors in the Ft framing bit position. Through the ERCNT.2  
bit, a framer can be programmed to also report errors in the Fs framing bit position. The PCVCR is disabled during  
receive loss-of-synchronization (RLOF = 1) conditions. See Table 11-12 for a detailed description of exactly what  
errors the PCVCR counts.  
Table 11-12 T1 Path-Code Violation Counting Arrangements  
WHAT IS COUNTED  
IN THE PCVCRs  
FRAMING MODE  
COUNT Fs ERRORS?  
D4  
D4  
ESF  
No  
Yes  
Don’t Care  
Errors in the Ft pattern  
Errors in both the Ft & Fs patterns  
Errors in the CRC6 codewords  
Register Name:  
Register Description:  
Address (hex):  
PCVCR1  
Path-Code Violation Count Register 1  
0052, 0252, 0452, 0652  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
PCVC15 PCVC14 PCVC13 PCVC12 PCVC11 PCVC10 PCVC9 PCVC8  
0
0
0
0
0
0
0
0
Bits 7 to 0 : Path-Code Violation Counter Bits 15 to 8 (PCVC15 to PCVC8) PCVC15 is the MSB of the 16-bit  
path-code violation count  
Register Name:  
Register Description:  
Address (hex):  
PCVCR2  
Path-Code Violation Count Register 2  
0053, 0253, 0453, 0653  
Bit #  
Name  
Default  
7
PCVC7  
0
6
PCVC6  
0
5
PCVC5  
0
4
PCVC4  
0
3
PCVC3  
0
2
PCVC2  
0
1
PCVC1  
0
0
PCVC0  
0
Bits 7 to 0 : Path-Code Violation Counter Bits 7 to 0 (PCVC7 to PCVC0) PCVC0 is the LSB of the 16-bit path-  
code violation count.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.6 T1 Frames Out-of-Sync Count Register (FOSCR)  
The FOSCR is used to count the number of multiframes that the receive synchronizer is out of sync. This number  
is useful in ESF applications needing to measure the parameters loss-of-frame count (LOFC) and ESF error events  
as described in AT&T publication TR54016. When the FOSCR is operated in this mode, it is not disabled during  
receive loss of synchronization (RLOF = 1) conditions. The FOSCR has alternate operating mode whereby it will  
count either errors in the Ft framing pattern (in the D4 mode) or errors in the FPS framing pattern (in the ESF  
mode). When the FOSCR is operated in this mode, it is disabled during receive loss-of-synchronization (RLOF = 1)  
conditions. See Table 11-13 for a detailed description of what the FOSCR is capable of counting.  
Table 11-13 T1 Frame Out-of-Sync Counting Arrangements  
FRAMING MODE  
COUNT MOS OR F–BIT  
ERRORS (ERCNT.1)  
WHAT IS COUNTED  
IN THE FOSCRs  
(RCR1.5)  
D4  
D4  
ESF  
ESF  
MOS  
F-Bit  
MOS  
F-Bit  
Number of multiframes out of sync  
Errors in the Ft pattern  
Number of multiframes out of sync  
Errors in the FPS pattern  
Register Name:  
Register Description:  
Address (hex):  
FOSCR1  
Frames Out-of-Sync Count Register 1  
0054, 0254, 0454, 0654  
Bit #  
Name  
Default  
7
FOS15  
0
6
FOS14  
0
5
FOS13  
0
4
FOS12  
0
3
2
1
FOS9  
0
0
FOS8  
0
FOS11 FOS10  
0
0
Bits 7 to 0 : Frames Out-of-Sync Counter Bits 15 to 8 (FOS15 to FOS8) FOS15 is the MSB of the 16-bit frames  
out-of-sync count.  
Register Name:  
Register Description:  
Address (hex):  
FOSCR2  
Frames Out-of-Sync Count Register 2  
0055, 0255, 0455, 0655  
Bit #  
Name  
Default  
7
FOS7  
0
6
FOS6  
0
5
FOS5  
0
4
FOS4  
0
3
FOS3  
0
2
FOS2  
0
1
FOS1  
0
0
FOS0  
0
Bits 7 to 0 : Frames Out-of-Sync Counter Bits 7 to 0 (FOS7 to FOS0) FOS0 is the LSB of the 16-bit frames  
out-of-sync count.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.7 DS0 Monitoring Function  
The DS26556 can monitor one DS0 (64kbps) channel in the transmit direction and one DS0 channel in the receive  
direction at the same time. In the receive direction, the RCM0 to RCM4 bits in the RDS0SEL register need to be  
properly set and the DS0 channel pointed to by the RCM0 to RCM4 bits will appear in the receive DS0 (RDS0M)  
register. The RCM4 to RCM0 bits should be programmed with the decimal decode of the appropriate T1 channel.  
T1 channels 1 through 24 map to register values 0 through 23. For example, if DS0 channel 15 in the receive  
direction needed to be monitored, then the following values would be programmed into RDS0SEL:  
RCM4 = 0  
RCM3 = 1  
RCM2 = 1  
RCM1 = 1  
RCM0 = 0  
Register Name:  
Register Description:  
Address (hex):  
RDS0SEL  
Receive-Channel Monitor Select  
0012, 0212, 0412, 0612  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
RCM4  
0
3
RCM3  
0
2
RCM2  
0
1
RCM1  
0
0
RCM0  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bits 4 to 0 : Receive-Channel Monitor Bits (RCM4 to RCM0) RCM0 is the LSB of a 5-bit channel select that  
determines which receive-DS0 channel data appears in the RDS0M register.  
Register Name:  
Register Description:  
Address (hex):  
RDS0M  
Receive-DS0 Monitor Register  
0060, 0260, 0460, 0660  
Bit #  
Name  
Default  
7
B1  
0
6
B2  
0
5
B3  
0
4
B4  
0
3
B5  
0
2
B6  
0
1
B7  
0
0
B8  
0
Bits 7 to 0 : Receive-DS0 Channel Bits (B1 to B8) Receive-channel data that has been selected by the receive-  
channel monitor select register. B8 is the LSB of the DS0 channel (last bit to be received).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.8 Receive Signaling Registers  
Register Name:  
Register Description:  
Address (hex):  
RSIGC  
Receive Signaling Control Register  
0013, 0213, 0413, 0613  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
RFSA1  
0
3
0
2
RSFF  
0
1
RSFE  
0
0
RSIE  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Receive-Force Signaling All Ones (RFSA1)  
0 = do not force robbed bit signaling to all ones  
1 = force signaling bits to all ones on a per-channel basis according to the RSAOI1–RSAOI3 registers  
Bit 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Receive-Signaling Force Freeze (RSFF). Freezes receive-side signaling at RSIG (and RSER if receive-  
signaling reinsertion is enabled); overrides receive-freeze enable (RFE).  
0 = do not force a freeze event  
1 = force a freeze event  
Bit 1 : Receive-Signaling Freeze Enable (RSFE)  
0 = no freezing of receive-signaling data occurs  
1 = allow freezing of receive-signaling data at RSIG (and RSER if receive-signaling reinsertion is enabled)  
Bit 0 : Receive-Signaling Integration Enable (RSIE)  
0 = signaling changes of state reported on any change in selected channels  
1 = signaling must be stable for three multiframes for a change of state to be reported  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSI1, RSI2, RSI3, RSI4  
Receive-Signaling Reinsertion Enable Registers  
00C8, 02C8, 04C8, 06C8  
Setting any of the CH1 through CH24 bits in the RSI1 through RSI3 registers causes signaling data to be  
reinserted for the associated channel. RSI4 is used for 2.048MHz backplane operation.  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1  
CH9  
CH17  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RSI1  
RSI2  
RSI3  
RSI4*  
Register Name:  
Register Description:  
Address (hex):  
RSAOI1, RSAOI2, RSAOI3,  
Receive-Signaling All-Ones Insertion Registers  
0038 to 003A, 0238 to 023A, 0438 to 043A, 0638 to 063A  
Setting any of the CH1 through CH24 bits in the RSAOI1 through RSAOI3 registers causes signaling data to be  
replaced with logic ones as received at the backplane.  
(MSB)  
CH8  
CH16  
CH24  
(LSB)  
CH1  
CH9  
CH7  
CH15  
CH23  
CH6  
CH14  
CH22  
CH5  
CH13  
CH21  
CH4  
CH12  
CH20  
CH3  
CH11  
CH19  
CH2  
CH10  
CH18  
RSAOI1  
RSAOI2  
RSAOI3  
CH17  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RS1 to RS12  
Receive Signaling Registers  
0040 to 004B, 0240 to 024B, 0440 to 044B, 0640 to 064B  
In the ESF framing mode, there can be up to four signaling bits per channel (A, B, C, and D). In the D4 framing  
mode, there are only two signaling bits per channel (A and B). In the D4 framing mode, the framer repeats the A  
and B signaling data in the C and D bit locations. Therefore, when the framer is operated in D4 framing mode, the  
user needs to retrieve the signaling bits every 1.5ms as opposed to 3ms for ESF mode. The receive-signaling  
registers are frozen and not updated during a loss-of-sync condition. They contain the most recent signaling  
information before the OOF occurred.  
(MSB)  
CH1-A  
CH2-A  
CH3-A  
CH4-A  
CH5-A  
CH6-A  
CH7-A  
CH8-A  
CH9-A  
(LSB)  
CH13-A CH13-B CH13-C CH13-D  
CH14-A CH14-B CH14-C CH14-D  
CH15-A CH15-B CH15-C CH15-D  
CH16-A CH16-B CH16-C CH16-D  
CH17-A CH17-B CH17-C CH17-D  
CH18-A CH18-B CH18-C CH18-D  
CH19-A CH19-B CH19-C CH19-D  
CH20-A CH20-B CH20-C CH20-D  
CH21-A CH21-B CH21-C CH21-D  
CH1-B  
CH2-B  
CH3-B  
CH4-B  
CH5-B  
CH6-B  
CH7-B  
CH8-B  
CH9-B  
CH1-C  
CH2-C  
CH3-C  
CH4-C  
CH5-C  
CH6-C  
CH7-C  
CH8-C  
CH9-C  
CH1-D  
CH2-D  
CH3-D  
CH4-D  
CH5-D  
CH6-D  
CH7-D  
CH8-D  
CH9-D  
RS1  
RS2  
RS3  
RS4  
RS5  
RS6  
RS7  
RS8  
RS9  
RS10  
RS11  
RS12  
CH10-A CH10-B CH10-C CH10-D CH22-A CH22-B CH22-C CH22-D  
CH11-A CH11-B CH11-C CH11-D CH23-A CH23-B CH23-C CH23-D  
CH12-A CH12-B CH12-C CH12-D CH24-A CH24-B CH24-C CH24-D  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSS1, RSS2, RSS3  
Receive Signaling Status Registers  
0098 to 009A, 0298 to 029A, 0498, to 049A  
When a channel’s signaling data changes state, the respective bit in registers RSS1–RSS3 is set and latched. The  
RSCOS bit (RLSR4.3) is set if the channel was also enabled by setting the appropriate bit in RSCSE1–3. The INT  
signal goes low if enabled by the interrupt mask bit RIM4.3.  
Bit #  
7
6
5
4
3
2
1
0
Name  
Name  
Name  
Default  
CH8  
CH16  
CH24  
0
CH7  
CH15  
CH23  
0
CH6  
CH14  
CH22  
0
CH5  
CH13  
CH21  
0
CH4  
CH12  
CH20  
0
CH3  
CH11  
CH19  
0
CH2  
CH10  
CH18  
0
CH1  
CH9  
CH17  
0
RSS1  
RSS2  
RSS3  
Note: Status bits in this register are latched.  
Register Name:  
Register Description:  
Address (hex):  
RSCSE1, RSCSE2, RSCSE3  
Receive-Signaling Change-of-State Enable  
00A8 to 00AA, 02A8 to 02AA, 04A8, to 04AA  
Setting any of the CH1 through CH24 bits in the RSS1 through RSS3 registers cause RSCOS (RLSR4.3) to be set  
when that channel’s signaling data changes state.  
Bit #  
7
6
5
4
3
2
1
0
Name  
Name  
Name  
Default  
CH8  
CH16  
CH24  
0
CH7  
CH15  
CH23  
0
CH6  
CH14  
CH22  
0
CH5  
CH13  
CH21  
0
CH4  
CH12  
CH20  
0
CH3  
CH11  
CH19  
0
CH2  
CH10  
CH18  
0
CH1  
CH9  
CH17  
0
RSCSE1  
RSCSE2  
RSCSE3  
11.4.9 T1 Receive Per-Channel Idle Code Insertion  
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive directions.  
Twenty-four receive idle definition registers (RIDR1–RIDR24) are provided to set the 8-bit idle code for each  
channel. The receive-channel idle code-enable registers (RCICE1–3) are used to enable idle code replacement on  
a per-channel basis.  
The receive-channel idle code-enable registers (RCICE1/2/3) are used to determine which of the 24 T1 channels  
from the T1 line to the backplane should be overwritten with the code placed in the receive idle-code definition  
register.  
Register Name:  
Register Description:  
Address (hex):  
RIDR1 to RIDR24  
Receive Idle-Code Definition Registers 1 to 24  
0020 to 0037, 0220 TO 0237, 0420 to 0437, 0620 to 0637  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bits 7 to 0 : Per-Channel Idle Code Bits (C7 to C0) C0 is the LSB of the code (this bit is transmitted last).  
Address 20H is for channel 1; address 37H is for channel 24.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCICE1, RCICE2, RCICE3  
Receive-Channel Idle Code-Enable Registers  
00D0 to 00D2, 02D0 to 02D2, 04D0 to 04D2, 06D0 t0 06D2  
Bit #  
Name  
Name  
Name  
Default  
7
6
5
4
3
2
1
0
CH8  
CH16  
CH24  
0
CH7  
CH15  
CH23  
0
CH6  
CH14  
CH22  
0
CH5  
CH13  
CH21  
0
CH4  
CH12  
CH20  
0
CH3  
CH11  
CH19  
0
CH2  
CH10  
CH18  
0
CH1  
CH9  
CH17  
0
RCICE1  
RCICE2  
RCICE3  
Bits 7 to 0 : Receive Channels 24 to 1 Code Insertion Control Bits (CH24 to CH1)  
0 = do not insert data from the idle code array into the receive data stream  
1 = insert data from the idle code array into the receive data stream  
11.4.10 T1 Receive Channel Mark Registers  
The Receive Channel Mark Registers (RCMR1/RCMR2/RCMR3/RCMR4) control the mapping of channels to the  
receive cell/packet interface and the RCHMRK pin. The RCHMRK signal is used internally to select which  
channels will be mapped to the receive cell/packet interface. Externally, the signal can be used to multiplex TDM  
data out of channels not used by the receive cell/packet interface. When the appropriate bits are set to 1, the  
receive cell/packet function is mapped to that channel and externally the RCHMRK pin is held high during the  
entire corresponding channel time. In T1 mode, only RCMR1 to RCMR3 and the LSB of RCMR4 are used.  
Register Name:  
Register Description:  
Address (hex):  
RCMR1, RCMR2, RCMR3  
Receive-Channel Mark Registers 1 to 3  
00C4 to 00C6, 02C4 to 02C6, 04C4 to 04C6, 06C4 to 06C6  
(MSB)  
(LSB)  
CH8  
CH16  
CH24  
CH7  
CH15  
CH23  
CH6  
CH14  
CH22  
CH5  
CH13  
CH21  
CH4  
CH12  
CH20  
CH3  
CH11  
CH19  
CH2  
CH10  
CH18  
CH1  
CH9  
CH17  
RCMR1  
RCMR2  
RCMR3  
Bits 7 to 0 : Receive Channels 24 to 1 Channel Mark Control Bits (CH24 to CH1)  
0 = force the RCHMRK pin to remain low during this channel time  
1 = force the RCHMRK pin high during this channel time  
Register Name:  
Register Description:  
Address (hex):  
RCMR4  
Receive-Channel Mark Register 4  
00C7, 02C7, 04C7, 06C7  
(MSB)  
(LSB)  
RFBIT  
RCMR4  
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Receive F Bit (RFBIT)  
RCMR4.0 = 0, RCHMRK low during the F-bit  
RCMR4.0 = 1, RCHMRK high during the F-bit  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RGCCR  
Receive Gapped Clock Control Register  
0085, 0285, 0485, 0685  
Bit #  
Name  
Default  
7
RCCF  
0
6
RGCE  
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
-
0
Bit 7 : Receive Channel Clock Format (RCCF) This bit controls the function of the RCHMRK pin went it is in the  
channel clock mode and the RGCCR.6 bit is set = 1. Channel clock mode is enabled in the RCHMRK Pin Function  
Select (RPFS) register.  
0 = 64kbps, clock output during all 8 bits  
1 = 56kbps, clock output during 7 MSBs  
Bit 6 :/ Receive Gapped Clock Enable (RGCE) This bit controls the function of the RCHMRK pin went it is in the  
channel clock mode. Channel clock mode is enabled in the RCHMRK Pin Function Select (RPFS) register.  
0 = RCHMRK outputs a pulse during the LSB of each channel time.  
1 = RCHMRK outputs a gapped bit clock as selected by the RGCCS1 through RGCCC4 registers.  
Bits 5 to 0 : Unused. Must be set = 0 for proper operation.  
11.4.11 Receive Fractional T1 Support (Gapped-Clock Mode)  
Register Name:  
Register Description:  
Address (hex):  
RGCCS1, RGCCS2, RGCCS3, RGCCS4  
Receive-Gapped-Clock Channel-Select Registers  
00CC to 00CF, 02CC to 02CF, 04CC to 04CF, 06CC to 06CF  
(MSB)  
(LSB)  
CH8  
CH16  
CH24  
CH32  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
CH1  
CH9  
CH17  
RGCCS1  
RGCCS2  
RGCCS3  
RGCCS4*  
CH25/F-Bit  
Bits 7 to 0 : Receive Channels 1 to 32 Gapped-Clock Channel Select Bits (CH1 to CH32) These bits control  
the RCHMRK pin when it is in the channel clock mode. Channel clock mode is enabled in the RCHMRK Pin  
Function Select (RPFS) register.  
0 = no clock is present on RCHMRK during this channel time  
1 = force a clock on RCHMRK during this channel time. The clock will be synchronous with RCLK.  
Note that RGCCS4 has two functions:  
When 2.048MHz backplane mode is selected, this register allows the user to enable the gapped  
clock on RCHMRK for any of the 32 possible backplane channels.  
When 1.544MHz backplane mode is selected, the LSB of this register determines whether or not a  
clock is generated on RCHMRK during the F-bit time:  
RGCCS4.0 = 0: do not generate a clock during the F-bit  
RGCCS4.0 = 1: generate a clock during the F-bit  
In this mode, RGCCS4.1—RGCCS4.7 should be set to 0.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.12 Receive T1 Bit-Oriented Code (BOC) Controller  
Register Name:  
Register Description:  
Address (hex):  
RBOCC  
Receive BOC Control Register  
0015, 0215, 0415, 0615  
Bit #  
Name  
Default  
7
RBR  
0
6
0
5
RBD1  
0
4
RBD0  
0
3
0
2
RBF1  
0
1
RBF0  
0
0
0
Bit 7 :Receive-BOC Reset (RBR) A 0-to-1 transition resets the BOC circuitry. Must be cleared and set again for a  
subsequent reset. Modifications to the RBF0, RBF1, RBD0, and RBD1 bits are not applied to the BOC controller  
until a BOC reset has been completed.  
Bit 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 4 : Receive-BOC-Disintegration Bits (RBD0, RBD1) The BOC Disintegration filter sets the number of  
message bits that must be received without a valid BOC in order to set the BC bit indicating that a valid BOC is no  
longer being received.  
RBD1  
RBD0  
Consecutive Message Bits for BOC Clear Identification  
0
0
1
1
0
1
0
1
16  
32  
48  
64 (Note 1)  
Bit 3 : Unused. Must be set = 0 for proper operation.  
Bits 2 to 1 : Receive-BOC-Filter Bits (RBF0, RBF1) The BOC filter sets the number of consecutive patterns that  
must be received without error prior to an indication of a valid message.  
RBF1  
RBF0  
Consecutive BOC Codes for Valid Sequence Identification  
0
0
1
1
0
1
0
1
None  
3
5
7 (Note 1)  
Bit 0 : Unused. Must be set = 0 for proper operation.  
Note 1: The DS26556’s BOC controller does not integrate and disintegrate concurrently. Therefore, if the  
maximum integration time and the maximum disintegration time are used together, BOC messages that repeat  
fewer than 11 times may not be detected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RBOC  
Receive BOC Register  
0063, 0263, 0463, 0663  
Bit #  
Name  
Default  
7
0
6
0
5
4
3
2
1
0
RBOC0  
0
RBOC5 RBOC4 RBOC3 RBOC2 RBOC1  
0
0
0
0
0
The RBOC Register always contains the last valid BOC received.  
Bits 7, 6 : Unused  
Bit 5 : BOC Bit 5 (RBOC5)  
Bit 4 : BOC Bit 4 (RBOC4)  
Bit 3 : BOC Bit 3 (RBOC3)  
Bit 2 : BOC Bit 2 (RBOC2)  
Bit 1 : BOC Bit 1 (RBOC1)  
Bit 0 : BOC Bit 0 (RBOC0)  
11.4.13 Receive SLC-96 Operation  
Register Name:  
Register Description:  
Address (hex):  
RSLC1, RSLC2, RSLC3  
Receive SLC96 Data Link Registers  
0064 to 0066, 0264 to 0266, 0464 to 0466, 0664 to 0666  
(MSB)  
(LSB)  
C8  
M2  
S = 1  
C7  
M1  
S4  
C6  
S = 0  
S3  
C5  
S = 1  
S2  
C4  
S = 0  
S1  
C3  
C11  
A2  
C2  
C10  
A1  
C1  
C9  
M3  
RSLC1  
RSLC2  
RSLC3  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.14 Receive FDL  
Register Name:  
Register Description:  
Address (hex):  
RFDL  
Receive FDL Register  
0062, 0262, 0462, 0662  
Bit #  
Name  
Default  
7
RFDL7  
0
6
RFDL6  
0
5
RFDL5  
0
4
RFDL4  
0
3
RFDL3  
0
2
RFDL2  
0
1
RFDL1  
0
0
RFDL0  
0
The receive FDL register (RFDL) reports the incoming facility data link (FDL) or the incoming Fs bits. The LSB is  
received first. In D4 framing mode, RFDL updates on multiframe boundaries and reports the six Fs bits in RFDL0–  
RFDL5.  
Bit 7 : Receive FDL Bit 7 (RFDL7) MSB of the received FDL code.  
Bit 6 : Receive FDL Bit 6 (RFDL6)  
Bit 5 : Receive FDL Bit 5 (RFDL5)  
Bit 4 : Receive FDL Bit 4 (RFDL4)  
Bit 3 : Receive FDL Bit 3 (RFDL3)  
Bit 2 : Receive FDL Bit 2 (RFDL2)  
Bit 1 : Receive FDL Bit 1 (RFDL1)  
Bit 0 : Receive FDL Bit 0 (RFDL0) LSB of the received FDL code.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.15 Programmable In-Band Loop-Code Detection  
Register Name:  
Register Description:  
Address (hex):  
RIBCC  
Receive In-Band Code Control Register  
0082, 0282, 0482, 0682  
Bit #  
Name  
Default  
7
0
6
0
5
RUP2  
0
4
RUP1  
0
3
RUP0  
0
2
RDN2  
0
1
RDN1  
0
0
RDN0  
0
Bits 7 & 6 : Unused. Must be set = 0 for proper operation.  
Bits 5 to 3 : Receive-Up-Code Length Definition Bits (RUP0 to RUP2)  
Length Selected  
RUP2  
RUP1  
RUP0  
(bits)  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
3
4
5
6
7
8 / 16  
Bits 2 to 0 : Receive-Down-Code Length Definition Bits (RDN0 to RDN2)  
Length Selected  
RDN2  
RDN1  
RDN0  
(bits)  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
3
4
5
6
7
8 / 16  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RUPCD1  
Receive-Up Code-Definition Register 1  
00AC, 02AC, 04AC, 06AC  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Note: Writing this register resets the detector’s integration period.  
Bit 7 : Receive-Up Code-Definition Bit 7 (C7) First bit of the repeating pattern.  
Bit 6 : Receive-Up Code-Definition Bit 6 (C6) A don’t care if a 1-bit length is selected.  
Bit 5 : Receive-Up Code-Definition Bit 5 (C5) A don’t care if a 1- or 2-bit length is selected.  
Bit 4 : Receive-Up Code-Definition Bit 4 (C4) A don’t care if a 1- to 3-bit length is selected.  
Bit 3 : Receive-Up Code-Definition Bit 3 (C3) A don’t care if a 1- to 4-bit length is selected.  
Bit 2 : Receive-Up Code-Definition Bit 2 (C2) A don’t care if a 1- to 5-bit length is selected.  
Bit 1 : Receive-Up Code-Definition Bit 1 (C1) A don’t care if a 1- to 6-bit length is selected.  
Bit 0 : Receive-Up Code-Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RUPCD2  
Receive-Up Code-Definition Register 2  
00AD, 02AD, 04AD, 06AD  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bit 7 : Receive-Up Code-Definition Bit 7 (C7) A don’t care if a 1- to 7-bit length is selected.  
Bit 6 : Receive-Up Code-Definition Bit 6 (C6) A don’t care if a 1- to 7-bit length is selected.  
Bit 5 : Receive-Up Code-Definition Bit 5 (C5) A don’t care if a 1- to 7-bit length is selected.  
Bit 4 : Receive-Up Code-Definition Bit 4 (C4) A don’t care if a 1- to 7-bit length is selected.  
Bit 3 : Receive-Up Code-Definition Bit 3 (C3) A don’t care if a 1- to 7-bit length is selected.  
Bit 2 : Receive-Up Code-Definition Bit 2 (C2) A don’t care if a 1- to 7-bit length is selected.  
Bit 1 : Receive-Up Code-Definition Bit 1 (C1) A don’t care if a 1- to 7-bit length is selected.  
Bit 0 : Receive-Up Code-Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
Register Name:  
Register Description:  
Address (hex):  
RDNCD1  
Receive-Down Code-Definition Register 1  
00AE, 02AE, 04AE, 06AE  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Note: Writing this register resets the detector’s integration period.  
Bit 7 : Receive-Down Code-Definition Bit 7 (C7) First bit of the repeating pattern.  
Bit 6 : Receive-Down Code-Definition Bit 6 (C6) A don’t care if a 1-bit length is selected.  
Bit 5 : Receive-Down Code-Definition Bit 5 (C5) A don’t care if a 1- or 2-bit length is selected.  
Bit 4 : Receive-Down Code-Definition Bit 4 (C4) A don’t care if a 1- to 3-bit length is selected.  
Bit 3 : Receive-Down Code-Definition Bit 3 (C3) A don’t care if a 1- to 4-bit length is selected.  
Bit 2 : Receive-Down Code-Definition Bit 2 (C2) A don’t care if a 1- to 5-bit length is selected.  
Bit 1 : Receive-Down Code-Definition Bit 1 (C1) A don’t care if a 1- to 6-bit length is selected.  
Bit 0 : Receive-Down Code-Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RDNCD2  
Receive-Down Code-Definition Register 2  
00AF, 02AF, 04AF, 06AF  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bit 7 : Receive-Down Code-Definition Bit 7 (C7) A don’t care if a 1- to 7-bit length is selected.  
Bit 6 : Receive-Down Code-Definition Bit 6 (C6) A don’t care if a 1- to 7-bit length is selected.  
Bit 5 : Receive-Down Code-Definition Bit 5 (C5) A don’t care if a 1- to 7-bit length is selected.  
Bit 4 : Receive-Down Code-Definition Bit 4 (C4) A don’t care if a 1- to 7-bit length is selected.  
Bit 3 : Receive-Down Code-Definition Bit 3 (C3) A don’t care if a 1- to 7-bit length is selected.  
Bit 2 : Receive-Down Code-Definition Bit 2 (C2) A don’t care if a 1- to 7-bit length is selected.  
Bit 1 : Receive-Down Code-Definition Bit 1 (C1) A don’t care if a 1- to 7-bit length is selected.  
Bit 0 : Receive-Down Code Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
209 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSCC  
In-Band Receive-Spare Control Register  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
RSC2  
0
1
RSC1  
0
0
RSC0  
0
Bits 2 to 0 : Receive-Spare Code-Length Definition Bits (RSC0 to RSC2)  
RSC2  
RSC1  
RSC0  
Length Selected (bits)  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
3
4
5
6
7
8 / 16  
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Register Name:  
Register Description:  
Address (hex):  
RSCD1  
Receive-Spare Code-Definition Register 1  
009C, 029C, 049C, 069C  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Note: Writing this register resets the detector’s integration period.  
Bit 7 : Receive-Spare Code-Definition Bit 7 (C7) First bit of the repeating pattern.  
Bit 6 : Receive-Spare Code-Definition Bit 6 (C6) A don’t care if a 1-bit length is selected.  
Bit 5 : Receive-Spare Code-Definition Bit 5 (C5) A don’t care if a 1- or 2-bit length is selected.  
Bit 4 : Receive-Spare Code-Definition Bit 4 (C4) A don’t care if a 1- to 3-bit length is selected.  
Bit 3 : Receive-Spare Code-Definition Bit 3 (C3) A don’t care if a 1- to 4-bit length is selected.  
Bit 2 : Receive-Spare Code-Definition Bit 2 (C2) A don’t care if a 1- to 5-bit length is selected.  
Bit 1 : Receive-Spare Code-Definition Bit 1 (C1) A don’t care if a 1- to 6-bit length is selected.  
Bit 0 : Receive-Spare Code-Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSCD2  
Receive-Spare Code-Definition Register 2  
009D, 029D, 049D, 069D  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bit 7 : Receive-Spare Code-Definition Bit 7 (C7) A don’t care if a 1- to 7-bit length is selected.  
Bit 6 : Receive-Spare Code-Definition Bit 6 (C6) A don’t care if a 1- to 7-bit length is selected.  
Bit 5 : Receive-Spare Code-Definition Bit 5 (C5) A don’t care if a 1- to 7-bit length is selected.  
Bit 4 : Receive-Spare Code-Definition Bit 4 (C4) A don’t care if a 1- to 7-bit length is selected.  
Bit 3 : Receive-Spare Code-Definition Bit 3 (C3) A don’t care if a 1- to 7-bit length is selected.  
Bit 2 : Receive-Spare Code-Definition Bit 2 (C2) A don’t care if a 1- to 7-bit length is selected.  
Bit 1 : Receive-Spare Code-Definition Bit 1 (C1) A don’t care if a 1- to 7-bit length is selected.  
Bit 0 : Receive-Spare Code-Definition Bit 0 (C0) A don’t care if a 1- to 7-bit length is selected.  
211 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.16 Receive HDLC Controller  
Register Name:  
Register Description:  
Address (hex):  
RHC  
Receive HDLC Control Register  
0010, 0210, 0410, 0610  
Bit #  
Name  
Default  
7
RCRCD  
0
6
RHR  
0
5
RHMS  
0
4
RHCS4  
0
3
RHCS3  
0
2
RHCS2  
0
1
RHCS1  
0
0
RHCS0  
0
Bit 7 : Receive CRC16 Display (RCRCD)  
0 = Do not write received CRC16 code to FIFO  
1= Write received CRC16 code to FIFO after last octet of packet  
Bit 6 : Receive HDLC Reset (RHR) Resets the receive-HDLC controller and flushes the receive FIFO. Must be  
cleared and set again for a subsequent reset.  
0 = Normal operation  
1 = Reset receive HDLC controller and flush the receive FIFO  
Bit 5 : Receive HDLC Mapping Select (RHMS)  
0 = Receive HDLC assigned to channels  
1 = Receive HDLC assigned to FDL (T1 mode), Sa bits (E1 mode)  
Bit 4 to Bit 0 : Receive HDLC Channel Select (RHCSx) These bits determine which DS0 is mapped to the  
HDLC controller when enabled with RHMS = 0. RHCS0 to RHCS4 = all zeros selects channel 1, RHCS0 to  
RHCS4 = all ones selects channel 32 (E1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RHBSE  
Receive HDLC Bit Suppress Register  
0011, 0211, 0411, 0611  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 7 : Receive Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Receive Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 5 : Receive Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 4 : Receive Channel Bit 5 Suppress (BSE5) Set to one to stop this bit from being used.  
Bit 3 : Receive Channel Bit 4 Suppress (BSE4) Set to one to stop this bit from being used.  
Bit 2 : Receive Channel Bit 3 Suppress (BSE3) Set to one to stop this bit from being used.  
Bit 1 : Receive Channel Bit 2 Suppress (BSE2) Set to one to stop this bit from being used.  
Bit 0 : Receive Channel Bit 1 Suppress (BSE1) LSB of the channel. Set to one to stop this bit from being used.  
11.4.16.1Receive HDLC FIFO Control  
Control of the receive FIFO is accomplished through the receive-HDLC FIFO control (RHFC). The FIFO control  
register sets the watermarks for the receive FIFO.  
When the receive FIFO fills above the high watermark, the RHWM bit (RRTS5.1) is set. RHWM is a real-time bit  
and remains set as long as the receive FIFO’s write pointer is above the watermark. If enabled, this condition can  
also cause an interrupt through the INT pin.  
Register Name:  
Register Description:  
Address (hex):  
RHFC  
Receive HDLC FIFO Control Register  
0087, 0287, 0487, 0687  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
RFHWM1  
0
0
RFHWM0  
0
Bits 7 to 2 : Unused. Must be set = 0 for proper operation.  
Bits 1 to 0 : Receive FIFO High Watermark Select (RFHWM0 to RFHWM1)  
Receive FIFO Watermark  
RFHWM1 RFHWM0  
(bytes)  
0
0
1
1
0
1
0
1
4
16  
32  
48  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.16.2Receive HDLC Packet Bytes Available  
The lower 6 bits of the receive-packet-bytes-available register indicates the number of bytes (0 through 64) that  
can be read from the receive FIFO. The value indicated by this register informs the host as to how many bytes can  
be read from the receive FIFO without going past the end of a message. This value refers to one of four  
possibilities: the first part of a packet, the continuation of a packet, the last part of a packet, or a complete packet.  
After reading the number of bytes indicated by this register, the host then checks the HDLC status registers for  
detailed message status.  
If the value in the RHPBA register refers to the beginning portion of a message or continuation of a message, then  
the MSB of the RHPBA register returns a 1. This indicates that the host may safely read the number of bytes  
returned by the lower 6 bits of the RHPBA register, but there is no need to check the information register since the  
packet has not yet terminated (successfully or otherwise).  
Register Name:  
Register Description:  
Address (hex):  
RHPBA  
Receive HDLC Packet Bytes Available Register  
00B5, 02B5, 04B5, 06B5  
Bit #  
Name  
Default  
7
MS  
0
6
RPBA6  
0
5
RPBA5  
0
4
RPBA4  
0
3
RPBA3  
0
2
RPBA2  
0
1
RPBA1  
0
0
RPBA0  
0
Bit 7 : Message Status (MS)  
0 = Bytes indicated by RPBA0 through RPBA6 are the end of a message. Host must check the HDLC  
Status register for details.  
1 = Bytes indicated by RPBA0 through RPBA6 are the beginning or continuation of a message. The host  
does not need to check the HDLC status.  
Bits 6–0 : Receive FIFO Packet Bytes Available Count (RPBA0 to RPBA6) RPBA0 is the LSB.  
Register Name:  
Register Description:  
Address (hex):  
RHF  
Receive HDLC FIFO Register  
00B6, 02B6, 04B6, 06B6  
Bit #  
Name  
Default  
7
RHD7  
0
6
RHD6  
0
5
RHD5  
0
4
RHD4  
0
3
RHD3  
0
2
RHD2  
0
1
RHD1  
0
0
RHD0  
0
Bit 7 : Receive HDLC Data Bit 7 (RHD7) MSB of a HDLC packet data byte.  
Bit 6 : Receive HDLC Data Bit 6 (RHD6)  
Bit 5 : Receive HDLC Data Bit 5 (RHD5)  
Bit 4 : Receive HDLC Data Bit 4 (RHD4)  
Bit 3 : Receive HDLC Data Bit 3 (RHD3)  
Bit 2 : Receive HDLC Data Bit 2 (RHD2)  
Bit 1 : Receive HDLC Data Bit 1 (RHD1)  
Bit 0 : Receive HDLC Data Bit 0 (RHD0) LSB of a HDLC packet data byte.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.16.3HDLC Status and Information  
RRTS5 and RLS5 provide status information for the receive HDLC controller. When a particular event has  
occurred (or is occurring), the appropriate bit in one of these registers is set to 1. With the latched bits, when an  
event occurs and a bit is set to 1, it remains set until the user reads that bit. The bit is cleared when it is read and it  
is not set again until the event has occurred again. The real-time bits report the current instantaneous conditions  
that are occurring and the history of these bits is not latched.  
Like the other latched-status registers, the user follows a read of the status bit with a write. The byte written to the  
register informs the device which of the latched bits the user wishes to clear (the real-time bits are not affected by  
writing to the status register). The user writes a byte to one of these registers, with a 1 in the bit positions the user  
wishes to clear and a zero in the bit positions the user wishes not to clear.  
The HDLC status register RLS5 can initiate a hardware interrupt through the INT output signal. Each of the events  
in this register can be either masked or unmasked from the interrupt pin through the receive-HDLC interrupt-mask  
register (RIM5). Interrupts force the INT signal low when the event occurs. The INT pin is allowed to return high (if  
no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.  
Register Name:  
Register Description:  
Address (hex):  
RRTS5  
Receive Real-Time Status Register 5 (HDLC)  
00B4, 02B4, 04B4, 06B4  
Bit #  
Name  
Default  
7
0
6
PS2  
0
5
PS1  
0
4
PS0  
0
3
0
2
0
1
RHWM  
0
0
RNE  
0
Note: All bits in this register are real-time.  
Bit 7 : Unused.  
Bits 6 to 4 : Receive Packet Status (PS2 to PS0) These are real-time bits indicating the status as of the last read  
of the receive FIFO.  
PS2 PS1  
PS0  
0
PACKET STATUS  
0
0
0
0
In Progress: End of message has not yet been reached.  
Packet OK: Packet ended with correct CRC codeword.  
1
CRC Error: A closing flag was detected, preceded by a corrupt CRC  
codeword.  
Abort: Packet ended because an abort signal was detected (seven or  
more ones in a row).  
Overrun: HDLC controller terminated reception of packet because  
receive FIFO is full.  
0
0
1
1
1
0
0
1
0
Bits 3 & 2 : Unused.  
Bit 1 : Receive-FIFO Above High-Watermark Condition (RHWM) Set when the receive 64-byte FIFO fills  
beyond the high watermark as defined by the receive-HDLC FIFO control register (RHFC).This is a real-time bit.  
Bit 0 : Receive-FIFO Not Empty Condition (RNE) Set when the receive 64-byte FIFO has at least one byte  
available for a read. This is a real-time bit.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS5  
Receive Latched Status Register 5 (HDLC)  
0094, 0295, 0494, 0694  
Bit #  
Name  
Default  
7
0
6
0
5
ROVR  
0
4
RHOBT  
0
3
RPE  
0
2
RPS  
0
1
RHWMS  
0
0
RNES  
0
Note: All bits in this register are latched and can cause interrupts.  
Bits 7 & 6 : Unused.  
Bit 5 : Receive FIFO Overrun (ROVR) Set when the receive HDLC controller has terminated packet reception  
because the FIFO buffer is full.  
Bit 4 : Receive HDLC Opening Byte Event (RHOBT) Set when the next byte available in the receive FIFO is the  
first byte of a message.  
Bit 3 : Receive Packet End Event (RPE) Set when the HDLC controller detects either the finish of a valid  
message (i.e., CRC check complete) or when the controller has experienced a message fault such as a CRC  
checking error, or an overrun condition, or an abort has been seen. This is a latched bit and is cleared when read.  
Bit 2 : Receive Packet Start Event (RPS) Set when the HDLC controller detects an opening byte. This is a  
latched bit and will be cleared when read.  
Bit 1 : Receive-FIFO Above High-Watermark Set Event (RHWMS) Set when the receive-64-byte FIFO crosses  
the high watermark as defined by the receive HDLC FIFO control register (RHFC). Rising edge detect of RHWM.  
Bit 0 : Receive-FIFO Not Empty Set Event (RNES) Set when the receive FIFO has transitioned from ‘empty’ to  
‘not-empty’ (at least one byte has been put into the FIFO). Rising edge detect of RNE.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM5  
Receive Interrupt Mask 5 (HDLC)  
00A4, 02A4, 04A4, 06A4  
Bit #  
Name  
Default  
7
0
6
0
5
ROVR  
0
4
RHOBT  
0
3
RPE  
0
2
RPS  
0
1
RHWMS  
0
0
RNES  
0
Bits 7 & 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Receive-FIFO Overrun (ROVR)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive-HDLC Opening-Byte Event (RHOBT)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Receive-Packet-End Event (RPE)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive-Packet-Start Event (RPS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Receive-FIFO Above High-Watermark Set Event (RHWMS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive-FIFO Not Empty Set Event (RNES)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.4.17 Receive BERT  
Data from the DS26556 receive framer can be ported to the on-chip BERT by using the registers described below.  
Either framed or unframed data can be provided to the BERT, controlled by the RBFUS bit in the RBICR. Any  
single DS0 or combination of DS0s can be extracted from the data stream up to the entire T1 payload, as  
controlled by the RBCS registers.  
Note that one BERT resource is shared among all 8 framers. Therefore, the RBEN bit should be set for only one  
framer at a time. If multiple framers have the RBEN bit set, the lower number framer is assigned the resource.  
Details concerning the BERT can be found in Section 13.  
Register Name:  
Register Description:  
Address (hex):  
RBICR  
Receive BERT Interface Control Register  
008A, 028A, 048A, 068A  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
RBDC  
0
1
RBFUS  
0
0
RBEN  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Receive BERT Direction Control (RBDC)  
0 = Receive Path: The BERT receives data from the network side via RPOS and RNEG.  
1 = Backplane: The BERT receives data from the system backplane via the TSER pin.  
Bit 1 : Receive BERT Framed/Unframed Select (RBFUS)  
0 = The framer does not provide data from the F-bit position (framed).  
1 = The framer clocks data from the F-bit position (unframed).  
Bit 0 : Receive BERT Enable (RBEN)  
0 = Receive BERT is not assigned to this framer.  
1 = Receive BERT is assigned to this framer.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RBCS1, RBCS2, RBCS3  
Receive BERT Channel Select Registers  
00D4 to 00D6, 02D4 to 02D6, 04D4 to 04D6, 06D4 to 06D6  
Setting any of the CH1 through CH24 bits in the RBCS1 through RBCS3 registers maps data from those channels  
to the on-board BERT. RBEN must be set to 1 for these registers to function. Multiple or all channels can be  
selected simultaneously. These registers affect the receive-side framer only.  
(MSB)  
CH8  
CH16  
CH24  
(LSB)  
CH1  
CH9  
CH7  
CH15  
CH23  
CH6  
CH14  
CH22  
CH5  
CH13  
CH21  
CH4  
CH12  
CH20  
CH3  
CH11  
CH19  
CH2  
CH10  
CH18  
RBCS1  
RBCS2  
RBCS3  
CH17  
Register Name:  
Register Description:  
Address (hex):  
RBBS  
Receive BERT Bit Suppress Register  
008B, 028B, 048B, 068B  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 7 : Receive Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Receive Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 5 : Receive Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 4 : Receive Channel Bit 5 Suppress (BSE5) Set to one to stop this bit from being used  
Bit 3 : Receive Channel Bit 4 Suppress (BSE4) Set to one to stop this bit from being used.  
Bit 2 : Receive Channel Bit 3 Suppress (BSE3) Set to one to stop this bit from being used.  
Bit 1 : Receive Channel Bit 2 Suppress (BSE2) Set to one to stop this bit from being used.  
Bit 0 : Receive Channel Bit 1 Suppress (BSE1) LSB of the channel. Set to one to stop this bit from being used.  
219 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5 T1 Transmit framer  
Table 11-14 T1 Transmit Framer Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
NAME  
FUNCTION  
PORT 3 + 400h  
PORT 4 + 600h  
0100-010F  
0110  
Unused. Must be set = 0 for proper operation  
Tx HDLC Control 1  
THC1  
THBSE  
THC2  
SSIE1  
SSIE2  
SSIE3  
0111  
0112  
0113  
Tx HDLC Bit Suppress  
Unused. Must be set = 0 for proper operation  
Tx HDLC Control 2  
Unused. Must be set = 0 for proper operation  
Tx Software Signaling Insertion Enable 1  
Tx Software Signaling Insertion Enable 2  
Tx Software Signaling Insertion Enable 3  
Unused. Must be set = 0 for proper operation  
Tx Idle Definition 1  
0114 - 0117  
0118  
0119  
011A  
011B – 011F  
0120  
TIDR1  
TIDR2  
TIDR3  
TIDR4  
TIDR5  
TIDR6  
TIDR7  
TIDR8  
TIDR9  
TIDR10  
TIDR11  
TIDR12  
TIDR13  
TIDR14  
TIDR15  
TIDR16  
TIDR17  
TIDR18  
TIDR19  
TIDR20  
TIDR21  
TIDR22  
TIDR23  
TIDR24  
0121  
0122  
0123  
0124  
0125  
0126  
0127  
0128  
Tx Idle Definition 2  
Tx Idle Definition 3  
Tx Idle Definition 4  
Tx Idle Definition 5  
Tx Idle Definition 6  
Tx Idle Definition 7  
Tx Idle Definition 8  
Tx Idle Definition 9  
Tx Idle Definition 10  
Tx Idle Definition 11  
Tx Idle Definition 12  
Tx Idle Definition 13  
Tx Idle Definition 14  
Tx Idle Definition 15  
Tx Idle Definition 16  
Tx Idle Definition 17  
Tx Idle Definition 18  
Tx Idle Definition 19  
Tx Idle Definition 20  
Tx Idle Definition 21  
Tx Idle Definition 22  
Tx Idle Definition 23  
Tx Idle Definition 24  
Unused. Must be set = 0 for proper operation  
Tx Signaling 1  
0129  
012A  
012B  
012C  
012D  
012E  
012F  
0130  
0131  
0132  
0133  
0134  
0135  
0136  
0137  
0138-013F  
0140  
TS1  
0141  
TS2  
Tx Signaling 2  
0142  
TS3  
Tx Signaling 3  
0143  
TS4  
Tx Signaling 4  
0144  
TS5  
Tx Signaling 5  
0145  
TS6  
Tx Signaling 6  
0146  
TS7  
Tx Signaling 7  
0147  
TS8  
Tx Signaling 8  
0148  
TS9  
Tx Signaling 9  
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ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0149  
014A  
014B  
014C – 014F  
0150  
NAME  
FUNCTION  
TS10  
TS11  
TS12  
TCICE1  
TCICE2  
TCICE3  
TFDL  
TBOC  
TSLC1  
TSLC2  
TSLC3  
TMMR  
TCR1  
TCR2  
TCR3  
TIOCR  
TGCCR  
TCR4  
THFC  
-
Tx Signaling 10  
Tx Signaling 11  
Tx Signaling 12  
Unused. Must be set = 0 for proper operation.  
Tx Channel Idle Code Enable 1  
Tx Channel Idle Code Enable 2  
Tx Channel Idle Code Enable 3  
Unused. Must be set = 0 for proper operation.  
Tx FDL  
0151  
0152  
0153-0161  
0162  
0163  
0164  
0165  
0166  
Tx BOC  
Tx SLC96 Data Link 1  
Tx SLC96 Data Link 2  
Tx SLC96 Data Link 3  
0167-017F  
0180  
Unused. Must be set = 0 for proper operation.  
Tx Master Mode  
0181  
0182  
0183  
0184  
0185  
0186  
0187  
0188  
0189  
018A  
018B  
018C  
018D  
018E  
018F  
0190  
Tx Control 1  
Tx Control 2  
Tx Control 3  
Tx I/O Configuration  
Tx Gapped Clock Control  
Tx Control 4  
Tx HDLC FIFO Control  
Unused. Must be set = 0 for proper operation.  
Tx DS0 Monitor Select  
Tx BERT Interface Control  
Tx BERT Bit Suppress Enable  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Tx Synchronizer Control  
Unused. Must be set = 0 for proper operation  
Tx Latched Status 1  
Tx Latched Status 2 (HDLC)  
Tx Latched Status 3 (SYNC)  
Unused. Must be set = 0 for proper operation  
Tx Interrupt Information Register  
Tx Interrupt Mask Register 1  
Tx Interrupt Mask Register 2 (HDLC)  
Tx Interrupt Mask Register 3 (SYNC)  
Unused. Must be set = 0 for proper operation  
Tx Code Definition 1  
TDS0SEL  
TBICR  
TBBS  
TSYNCC  
-
TLS1  
TLS2  
TLS3  
0191  
0192  
0193-019E  
019F  
TIIR  
01A0  
01A1  
01A2  
TIM1  
TIM2  
TIM3  
TCD1  
TCD2  
TRTS2  
TFBA  
THF  
01A3-01AB  
01AC  
01AD  
01AE  
01AF  
01B0  
01B1  
01B2  
01B3  
01B4  
Tx Code Definition 2  
Unused. Must be set = 0 for proper operation  
Unused. Must be set = 0 for proper operation  
Unused. Must be set = 0 for proper operation  
Tx Real-Time Status Register 2 (HDLC)  
Unused. Must be set = 0 for proper operation  
Tx HDLC FIFO Buffer Available  
Tx HDLC FIFO  
01B5-01BA  
01BB  
TDS0M  
Unused. Must be set = 0 for proper operation  
Tx DS0 Monitor  
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ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
01BC-01C3  
01C4  
NAME  
FUNCTION  
Unused. Must be set = 0 for proper operation  
TCMR1  
TCMR2  
TCMR3  
TCMR4  
THSCS1  
THSCS2  
THSCS3  
THSCS4  
TGCCS1  
TGCCS2  
TGCCS3  
TGCCS4  
PCL1  
PCL2  
PCL3  
TBPCS1  
TBPCS2  
TBPCS3  
Tx Channel Mark 1  
Tx Channel Mark 2  
Tx Channel Mark 3  
Tx Channel Mark 4  
01C5  
01C6  
01C7  
01C8  
01C9  
01CA  
01CB  
01CC  
01CD  
01CE  
01CF  
01D0  
01D1  
01D2  
01D3  
01D4  
Tx Hardware Signaling Channel Select 1  
Tx Hardware Signaling Channel Select 2  
Tx Hardware Signaling Channel Select 3  
Tx Hardware Signaling Channel Select 4  
Tx Gapped Clock Channel Select 1  
Tx Gapped Clock Channel Select 2  
Tx Gapped Clock Channel Select 3  
Tx Gapped Clock Channel Select 4  
Per-Channel Loopback Enable 1  
Per-Channel Loopback Enable 2  
Per-Channel Loopback Enable 3  
Unused. Must be set = 0 for proper operation  
Tx BERT Channel Select 1  
01D5  
01D6  
Tx BERT Channel Select 2  
Tx BERT Channel Select 3  
Unused. Must be set = 0 for proper operation  
01D7 – 01FF  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.1 Transmit-Master Mode Register  
The transmit-master mode register (TMMR) controls the initialization of the transmit-side formatter. The FRM_EN  
bit may be left ‘low’ if the formatter for that particular port is not going to be used, putting the circuit in a low-power  
(sleep) state.  
Register Name:  
Register Description:  
Address (hex):  
TMMR  
Transmit Master Mode Register  
0180  
Bit #  
Name  
Default  
7
6
5
0
4
0
3
0
2
0
1
SFTRST  
0
0
T1/E1  
0
FRM_EN INIT_DONE  
0
0
Bit 7 : Framer Enable (FRM_EN) This bit must be written with the desired value prior to setting INIT_DONE.  
0 = Framer disabled (held in low-power state)  
1 = Framer enabled (all features active)  
Bit 6 : Initialization Done (INIT_DONE) The host (user) must set this bit once he/she has written the  
configuration registers. The host is required to write or clear all RAM based registers (addresses 100H to 17FH)  
prior to setting this bit. Once INIT_DONE is set, the internal processor will check the FRM_EN bit. If enabled, the  
internal processor continues executing based on the initial configuration.  
Bits 5 to 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : Soft Reset (SFTRST) Level-sensitive processor reset. Should be taken high then low to reset and initialize  
the internal processor.  
0 = Normal operation  
1 = Hold the internal RISC in reset. This bit only affects the transmit-side processor.  
Bit 0 : Transmitter T1/E1 Mode Select (T1/E1) Sets operating mode for transmitter only! This bit must be written  
with the desired value prior to setting INIT_DONE.  
0 = T1 operation  
1 = E1 operation  
11.5.2 Interrupt Information Registers  
The interrupt information registers provide an indication of which DS26556 status registers are generating an  
interrupt. When an interrupt occurs, the host can read TIIR to quickly identify which of the transmit status registers  
are causing the interrupt(s). These are real-time registers in that the bits will clear once the appropriate interrupt  
has been serviced and cleared.  
Register Name:  
Register Description:  
Address (hex):  
TIIR  
Transmit Interrupt Information Register  
019F  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
TLS3  
0
1
TLS2  
0
0
TLS1  
0
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.3 T1 Transmit Control Registers  
Register Name:  
Register Description:  
Address (hex):  
TCR1  
Transmit Control Register 1  
0181  
Bit #  
Name  
Default  
7
TJC  
0
6
TFPT  
0
5
TCPT  
0
4
TSSE  
0
3
GB7S  
0
2
TB8ZS  
0
1
TAIS  
0
0
TRAI  
0
Bit 7 : Transmit Japanese CRC6 Enable (TJC)  
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)  
1 = use Japanese standard JT–G704 CRC6 calculation  
Bit 6 : Transmit F-Bit Pass-Through (TFPT)  
0 = F bits sourced internally  
1 = F bits sampled at TSER  
Bit 5 : Transmit CRC Pass-Through (TCPT)  
0 = source CRC6 bits internally  
1 = CRC6 bits sampled at TSER during F-bit time  
Bit 4 : Transmit-Software Signaling Enable (TSSE)  
0 = do not source signaling data from the TSx registers regardless of the SSIEx registers. The SSIEx  
registers still define which channels are to have B7 stuffing performed.  
1 = source signaling data as enabled by the SSIEx registers.  
Bit 3 : Global Bit 7 Stuffing (GB7S)  
0 = allow the SSIEx registers to determine which channels containing all zeros are to be bit 7 stuffed  
1 = force bit 7 stuffing in all-zero byte channels regardless of how the SSIEx registers are programmed  
Bit 2 : Transmit B8ZS Enable (TB8ZS)  
0 = B8ZS disabled  
1 = B8ZS enabled  
Bit 1 : Transmit Alarm Indication Signal (TAIS)  
0 = transmit data normally  
1 = transmit an unframed all-ones code  
Bit 0 : Transmit Remote Alarm Indication (TRAI)  
0 = do not transmit remote alarm  
1 = transmit remote alarm  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCR2  
Transmit Control Register 2  
0182  
Bit #  
Name  
Default  
7
6
5
0
4
FBCT2  
0
3
FBCT1  
0
2
TD4RM  
0
1
PDE  
0
0
TB7ZS  
0
TFDLS TSLC96  
0
0
Bit 7 : TFDL Register Select (TFDLS)  
0 = source FDL or Fs bits from the internal TFDL register or the SLC-96 data formatter (TCR2.6)  
1 = source FDL or Fs bits from the internal HDLC controller  
Bit 6 : Transmit SLC–96 (TSLC96) Set this bit to a one in SLC-96 framing applications. Must be set to source the  
SLC-96 alignment pattern and data from the TSLC1-3 registers. See Section 11.4.9 for details.  
0 = SLC–96 insertion disabled  
1 = SLC–96 insertion enabled  
Bit 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : F Bit Corruption Type 2 (FBCT2) Setting this bit high enables the corruption of one Ft (D4 framing mode)  
or FPS (ESF framing mode) bit in every 128 Ft or FPS bits as long as the bit remains set.  
Bit 3 : F Bit Corruption Type 1 (FBCT1) A low-to-high transition of this bit causes the next three consecutive Ft  
(D4 framing mode) or FPS (ESF framing mode) bits to be corrupted causing the remote end to experience a loss of  
synchronization.  
Bit 2 : Transmit D4 RAI Select (TD4RM)  
0 = zeros in bit 2 of all channels  
1 = a one in the S-bit position of frame 12  
Bit 1 : Pulse Density Enforcer Enable (PDE) The framer always examines both the transmit and receive data  
streams for violations of the following rules which are required by ANSI T1.403: no more than 15 consecutive zeros  
and at least N ones in each and every time window of 8 x (N +1) bits where N = 1 through 23. Violations for the  
transmit and receive data streams are reported in the TLS1.3 and RLS2.7 bits respectively. When this bit is set to  
one, the DS26556 will force the transmitted stream to meet this requirement no matter the content of the  
transmitted stream. When running B8ZS, this bit should be set to zero since B8ZS encoded data streams cannot  
violate the pulse density requirements.  
0 = disable transmit pulse density enforcer  
1 = enable transmit pulse density enforcer  
Bit 0 : Transmit Side Bit 7 Zero Suppression Enable (TB7ZS)  
0 = no stuffing occurs  
1 = force bit 7 to a one as determined by the GB7S bit at TCR1.3  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCR3  
Transmit Control Register 3  
0183  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
TCSS1  
0
4
TCSS0  
0
3
-
0
2
TFM  
0
1
IBVD  
0
0
TLOOP  
0
Bits 7 & 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Transmit Clock Source Select Bit 1 (TCSS1)  
TCSS1  
TCSS0  
Transmit Clock Source  
0
0
The TCLK pin is always the source of Transmit Clock.  
Switch to the clock present at RCLK when the signal at the TCLK pin  
fails to transition after 1 channel time.  
0
1
1
1
0
1
For Future Use  
Use the signal present at RCLK as the Transmit Clock. The TCLK pin  
is ignored.  
Bit 4 : Transmit Clock Source Select Bit 0 (TCSS0)  
Bit 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Transmit Frame Mode Select (TFM)  
0 = ESF framing mode  
1 = D4 framing mode  
Bit 1 : Insert BPV (IBPV) A 0-to-1 transition on this bit will cause a single BiPolar Violation (BPV) to be inserted  
into the transmit data stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next  
occurrence of three consecutive ones to insert the BPV. This bit must be cleared and set again for a subsequent  
error to be inserted.  
Bit 0 : Transmit Loop-Code Enable (TLOOP) See Section 11.4.10 for details.  
0 = transmit data normally  
1 = replace normal transmitted data with repeating code as defined in registers TCD1 and TCD2  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCR4  
Transmit Control Register 4  
0186  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
TRAIM  
0
2
TAISM  
0
1
TC1  
0
0
TC0  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit RAI Mode (TRAIM) Determines the pattern sent when TRAI (TCR1.0) is activated in ESF frame  
mode only.  
0 = transmit normal RAI upon activation with TCR1.0  
1 = transmit RAI-CI (T1.403) upon activation with TCR1.0  
Bit 2 : Transmit AIS Mode (TAISM) Determines the pattern sent when TAIS (TCR1.1) is activated.  
0 = transmit normal AIS (unframed all ones) upon activation with TCR1.1  
1 = transmit AIS-CI (T1.403) upon activation with TCR1.1  
Bits 1 to 0 : Transmit Code Length Definition Bits (TC0 to TC1)  
TC1  
0
TC0  
0
Length Selected (bits)  
5
0
1
6 / 3  
1
0
7
1
1
16 / 8 / 4 / 2 / 1  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIOCR  
Transmit I/O Configuration Register  
0184  
Bit #  
Name  
Default  
7
6
5
4
3
HSSM  
0
2
TSIO  
0
1
TSDW  
0
0
TSM  
0
TCLKINV TSYNCINV HSSYNCINV HSCLKM  
0
0
0
0
Bit 7 : TCLK Invert (TCLKINV)  
0 = No inversion  
1 = Invert  
Bit 6 : TSYNC Invert (TSYNCINV)  
0 = No inversion  
1 = Invert  
Bit 5 : HSSYNC Invert (HSSYNCINV)  
0 = No inversion  
1 = Invert  
Bit 4 : HSYSCLK Mode Select (HSCLKM)  
0 = if HSYSCLK is 1.544MHz  
1 = if HSYSCLK is 2.048/4.096/8.192/16.384MHz  
Note: This bit setting must match RIOCR.HSCLKM.  
Bit 3 : HSSYNC Mode Select (HSSM) Selects frame or multiframe mode for the HSSYNC pin.  
0 = frame mode  
1 = multiframe mode  
Bit 2 : TSYNC I/O Select (TSIO)  
0 = TSYNC is an input  
1 = TSYNC is an output  
Bit 1 : TSYNC Doublewide (TSDW) (Note: This bit must be set to zero when TSYNC is an input (TSIO=0) or  
when TSYNC is in multiframe output mode (TSM = 1).  
0 = do not pulse double wide in signaling frames  
1 = do pulse double wide in signaling frames  
Bit 0 : TSYNC Mode Select (TSM) Selects frame or multiframe mode for the TSYNC pin. Valid when TSYNC is an  
output.  
0 = frame mode  
1 = multiframe mode  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.4 T1 Transmit Status and Information  
When a particular event has occurred (or is occurring), the appropriate bit in one of these registers will be set to a  
one. Status bits may operate in either a latched or real-time fashion. Some latched bits may be enabled to  
generate a hardware interrupt via the INT signal.  
Real-Time Bits  
Some status bits operate in a real-time fashion. These bits are read-only and indicate the present state of an alarm  
or a condition. Real time bits will remain stable, and valid during the host read operation. The current value of the  
internal status signals can be read at any time from the real time status registers without changing any the latched  
status register bits  
Latched Bits  
When an event or an alarm occurs and a latched bit is set to a one, it will remain set until cleared by the user.  
These bits typically respond on a ‘change-of-state’ for an alarm, condition, or event; and operate in a read-then-  
write fashion. The user should read the value of the desired status bit, and then write a ‘1’ to that particular bit  
location in order to clear the latched value (write a ‘0’ to locations not to be cleared). Once the bit is cleared, it will  
not be set again until the event has occurred again.  
Mask Bits  
Some of the alarms and events can be either masked or unmasked from the interrupt pin via the Interrupt Mask  
Registers (TIMx). When unmasked, the INT signal will be forced low when the enabled event or condition occurs.  
The INT pin will be allowed to return high (if no other unmasked interrupts are present) when the user reads then  
clears (with a write) the alarm bit that caused the interrupt to occur. Note that the latched status bit and the INT pin  
will clear even if the alarm is still present.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TLS1  
Transmit Latched Status Register 1  
0190, 0390, 0590, 0790  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
TSLC96  
0
3
TPDV  
0
2
TMF  
0
1
LOTCC  
0
0
LOTC  
0
All bits in this register are latched and can cause interrupts.  
Bits 7 to 5: Unused.  
Bit 4 : Transmit SLC96 Multiframe Event (TSLC96) When enabled by TCR2.6, this bit will set once per SLC96  
multiframe (72 frames) to alert the host that new data may be written to the TSLC1-TSLC3 registers. See section  
11.5.13.  
Bit 3 : Transmit Pulse Density Violation Event (TPDV) Set when the transmit data stream does not meet the  
ANSI T1.403 requirements for pulse density.  
Bit 2 : Transmit Multiframe Event (TMF) Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF  
boundaries.  
Bit 1 : Loss of Transmit Clock Condition Clear (LOTCC) Set when the LOTC condition has cleared (a clock has  
been sensed at the TCLK pin).  
Bit 0 : Loss of Transmit Clock Condition (LOTC) Set when the TCLK pin has not transitioned for approximately  
3 clock periods. Will force the LOTC pin high if enabled. This bit can be cleared by the host even if the condition is  
still present. The LOTC pin will remain high while the condition exists, even if the host has cleared the status bit.  
If enabled by TIM1.0, the INT pin will transition low when this bit is set, and transition high when this bit is cleared  
(if no other unmasked interrupt conditions exist).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIM1  
Transmit Interrupt Mask Register 1  
01A0, 03A0, 05A0, 07A0  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
TSLC96  
0
3
TPDV  
0
2
TMF  
0
1
LOTCC  
0
0
LOTC  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Transmit SLC96 Multiframe Event (TSLC96)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Transmit Pulse Density Violation Event (TPDV)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Transmit Multiframe Event (TMF)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Loss of Transmit Clock Clear Condition (LOTCC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Loss of Transmit Clock Condition (LOTC)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.5 T1 Per-Channel Loopback  
Each of the bit position in the Per-Channel Loopback Registers (PCLR1/PCLR2/PCLR3) represent a DS0 channel  
in the outgoing frame. When these bits are set to a one, data from the corresponding receive channel will replace  
the data on TSER for that channel.  
Register Name:  
Register Description:  
Address (hex):  
PCL1  
Per-Channel Loopback Enable Register 1  
01D0, 03D0, 05D0, 07D0  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 : Per-Channel Loopback Enable for Channels 1 to 24 (CH8 to CH1)  
0 = Loopback disabled  
1 = Enable Loopback. Source data from the corresponding receive channel  
Register Name:  
Register Description:  
Address (hex):  
PCL2  
Per-Channel Loopback Enable Register 2  
01D1, 03D1, 05D1, 07D1  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 : Per-Channel Loopback Enable for Channels 1 to 24 (C16 to CH9)  
0 = Loopback disabled  
1 = Enable Loopback. Source data from the corresponding receive channel  
Register Name:  
Register Description:  
Address (hex):  
PCL3  
Per-Channel Loopback Enable Register 3  
01D2, 03D2, 05D2, 07D2  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 : Per-Channel Loopback Enable for Channels 1 to 24 (CH24 to CH17)  
0 = Loopback disabled  
1 = Enable Loopback. Source data from the corresponding receive channel  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.6 T1 Transmit DS0 Monitoring Function  
Register Name:  
Register Description:  
Address (hex):  
TDS0SEL  
Transmit DS0 Channel Monitor Select  
0189, 0389, 0589, 0789  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
TCM4  
0
3
TCM3  
0
2
TCM2  
0
1
TCM1  
0
0
TCM0  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bits 4 to 0 : Transmit Channel Monitor Bits (TCM0 to TCM4) TCM0 is the LSB of a 5 bit channel select that  
determines which transmit channel data will appear in the TDS0M register.  
Register Name:  
Register Description:  
Address (hex):  
TDS0M  
Transmit DS0 Monitor Register  
01BB, 03BB, 05BB, 07BB  
Bit #  
Name  
Default  
7
B1  
0
6
B2  
0
5
B3  
0
4
B4  
0
3
B5  
0
2
B6  
0
1
B7  
0
0
B8  
0
Bits 7 to 0 : Transmit DS0 Channel Bits (B1 to B8) Transmit channel data that has been selected by the  
Transmit Channel Monitor Select Register. B8 is the LSB of the DS0 channel (last bit to be transmitted).  
11.5.7 T1 Transmit Signaling Operation  
Register Name:  
Register Description:  
Address (hex):  
TS1 TO TS12  
Transmit Signaling Registers (T1 MODE)  
0140 – 014B, 0340 – 034B, 0540 – 054B, 0740 – 074B  
(MSB)  
(LSB)  
CH13-A CH13-B CH13-C CH13-D TS1  
CH1-A  
CH2-A  
CH3-A  
CH4-A  
CH5-A  
CH6-A  
CH7-A  
CH8-A  
CH9-A  
CH1-B  
CH2-B  
CH3-B  
CH4-B  
CH5-B  
CH6-B  
CH7-B  
CH8-B  
CH9-B  
CH1-C  
CH2-C  
CH3-C  
CH4-C  
CH5-C  
CH6-C  
CH7-C  
CH8-C  
CH9-C  
CH1-D  
CH2-D  
CH3-D  
CH4-D  
CH5-D  
CH6-D  
CH7-D  
CH8-D  
CH9-D  
CH14-A CH14-B CH14-C CH14-D TS2  
CH15-A CH15-B CH15-C CH15-D TS3  
CH16-A CH16-B CH16-C CH16-D TS4  
CH17-A CH17-B CH17-C CH17-D TS5  
CH18-A CH18-B CH18-C CH18-D TS6  
CH19-A CH19-B CH19-C CH19-D TS7  
CH20-A CH20-B CH20-C CH20-D TS8  
CH21-A CH21-B CH21-C CH21-D TS9  
CH10-A CH10-B CH10-C CH10-D CH22-A CH22-B CH22-C CH22-D TS10  
CH11-A CH11-B CH11-C CH11-D CH23-A CH23-B CH23-C CH23-D TS11  
CH12-A CH12-B CH12-C CH12-D CH24-A CH24-B CH24-C CH24-D TS12  
Note: In D4 framing mode, the C and D bits are not used.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
SSIE1  
Software Signaling Insertion Enable Register 1  
0118, 0318, 0518, 0718  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 8 to 8 (CH8 to CH1) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
Register Name:  
Register Description:  
Address (hex):  
SSIE2  
Software Signaling Insertion Enable Register 2  
0119, 0319, 0519, 0719  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 16 to 9 (CH16 TO CH9) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
Register Name:  
Register Description:  
Address (hex):  
SSIE3  
Software Signaling Insertion Enable Register 3  
011A, 031A, 051A, 071A  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 24 to 17 (CH24 TO CH17) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THSCS1  
Transmit Hardware Signaling Channel Select Register 1  
01C8, 03C8, 05C8, 07C8  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 8 to 1 (CH8 to CH1). This function is  
used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
Register Name:  
Register Description:  
Address (hex):  
THSCS2  
Transmit Hardware Signaling Channel Select Register 2  
01C9, 03C9, 05C9, 07C9  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 16 to 9 (CH16 to CH9). This function  
is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THSCS3  
Transmit Hardware Signaling Channel Select Register 3  
01CA, 03CA, 05CA, 07CA  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 24 to 17 (CH24 to CH17 This function  
is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
Register Name:  
Register Description:  
Address (hex):  
THSCS4  
Transmit Hardware Signaling Channel Select Register 4  
01CB, 03CB, 05CB, 07CB  
Bit #  
Name  
Default  
7
CH32  
0
6
CH31  
0
5
CH30  
0
4
CH29  
0
3
CH28  
0
2
CH27  
0
1
CH26  
0
0
CH25  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 32 to 25 (CH32 to CH25). This  
function is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine  
which channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.8 T1 Transmit Per-Channel Idle Code Insertion  
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive directions.  
Twenty-four Transmit Idle Definition Registers (TIDR1-TIDR24) are provided to set the 8-bit idle code for each  
channel. The Transmit Channel Idle Code Enable registers (TCICE1-3) are used to enable idle code replacement  
on a per channel basis.  
Register Name:  
Register Description:  
Address (hex):  
TIDR1 to TIDR24  
Transmit Idle Code Definition Registers 1 to 24  
0120 to 0137, 0320 to 0337, 0520 to 0537, 0720 to 0737  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bits 7 to 0 : Per-Channel Idle Code Bits (C0 to C7) C0 is the LSB of the Code (this bit is transmitted last).  
Address 120H is for channel 1, address 137H is for channel 24. The Transmit Channel Idle Code Enable Registers  
(TCICE1/2/3) are used to determine which of the 24 T1 channels from the backplane should be overwritten with  
the code placed in the Transmit Idle Code Definition Register.  
Register Name:  
Register Description:  
Address (hex):  
TCICE1  
Transmit Channel Idle Code Enable Register 1  
0150, 0350, 0550, 0750  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 : Transmit Channels 8 to 1 Code Insertion Control Bits (CH8 to CH1)  
0 = do not insert data from the Idle Code Array into the transmit data stream  
1 = insert data from the Idle Code Array into the transmit data stream  
Register Name:  
Register Description:  
Address (hex):  
TCICE2  
Transmit Channel Idle Code Enable Register 2  
0151, 0351, 0551, 0751  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 : Transmit Channels 16 to 9 Code Insertion Control Bits (CH16 to CH9)  
0 = do not insert data from the Idle Code Array into the transmit data stream  
1 = insert data from the Idle Code Array into the transmit data stream  
Register Name:  
Register Description:  
Address (hex):  
TCICE3  
Transmit Channel Idle Code Enable Register 3  
0152, 0352, 0552, 0752  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 : Transmit Channels 24 to 17 Code Insertion Control Bits (CH24 to CH17)  
0 = do not insert data from the Idle Code Array into the transmit data stream  
1 = insert data from the Idle Code Array into the transmit data stream  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.9 T1 Transmit Channel Mark Registers  
Register Name:  
Register Description:  
Address (hex):  
TCMR1  
Transmit Channel Mark Register 1  
01C4, 03C4, 05C4, 07C4  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 : Transmit Channels 8 to 8 Channel Mark Control Bits (CH8 to CH1)  
0 = force the TCHMRK pin to remain low during this channel time  
1 = force the TCHMRK pin high during this channel time  
Register Name:  
Register Description:  
Address (hex):  
TCMR2  
Transmit Channel Mark Register 2  
01C5, 03C5, 05C5, 07C5  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 : Transmit Channels 16 to 9 Channel Mark Control Bits (CH16 to CH9)  
0 = force the TCHMRK pin to remain low during this channel time  
1 = force the TCHMRK pin high during this channel time  
Register Name:  
Register Description:  
Address (hex):  
TCMR3  
Transmit Channel Mark Register 3  
01C6, 03C6, 05C6, 07C6  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 : Transmit Channels 24 to 17 Channel Mark Control Bits (CH24 to CH17)  
0 = force the TCHMRK pin to remain low during this channel time  
1 = force the TCHMRK pin high during this channel time  
In T1 mode, the LSB of TCMR4 determines whether or not the TCHMRK signal will pulse high during  
the F-Bit time:  
Register Name:  
TCMR4  
Register Description:  
Address (hex):  
Transmit Channel Mark Register 4  
01C7, 03C7, 05C7, 07C7  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
T1FBM  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : T1 F-Bit Mark (T1FBM) In T1 mode, the LSB of TCMR4 determines whether or not the TCHMRK signal will  
pulse high during the F-Bit time:  
0 = do not pulse TCHMRK during the F-Bit  
1 = pulse TCHMRK during the F-Bit  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TGCCR  
Transmit Gapped Clock Control Register  
185h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
6
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
-
0
TDATFMT TGCLKEN  
0
0
Bit 7 : Transmit Channel Data Format (TDATFMT)  
0 = 64KBps (data contained in all 8 bits)  
1 = 56KBps (data contained in 7 out of the 8 bits)  
Bit 6 : Transmit Gapped Clock Enable (TGPCKEN) If the TCHMRK pin is in the channel clock mode then this bit  
determines if TCHMRK outputs a pulse during the LSB of all channels or a gapped clock during selected channels.  
0 = pulse during LSB of all  
1 = gapped clock during selected channels  
Bits 5 to 0 : Unused. Must be set = 0 for proper operation.  
11.5.10 Fractional T1 Support (Gapped Clock Mode)  
The DS26556 can be programmed to output gapped clocks for selected channels in transmit path. When the  
TCHMRK pin is in the channel clock mode and gapped channel clock is enabled, a gated clock is output on the  
TCHMRK pin during selected channel times. The channel selection is controlled via the transmit-gapped-clock  
channel-select registers (TGCCS1-TGCCS4). If TCHMRK is in the channel clock mode clock mode is enabled by  
the TGCLKEN bit (TESCR.6). Both 56kbps and 64kbps channel formats are supported as determined by  
TESCR.7. When 56kbps mode is selected, the clock corresponding to the Data/Control bit in the channel is  
omitted (only the seven most significant bits of the channel have clocks).  
Register Name:  
Register Description:  
Address (hex):  
TGCCS1, TGCCS2, TGCCS3, TGCCS4  
Transmit Gapped Clock Channel Select Registers  
1CCh, 1CDh, 1CEh, 1CFh [+ (200h x n) : where n = 0 to 3, for Ports 1 to 4]  
(MSB)  
(LSB)  
CH8  
CH16  
CH24  
CH32  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
CH1  
CH9  
CH17  
TGCCS1  
TGCCS2  
TGCCS3  
TGCCS4*  
CH25/Fbit  
Bits 7 to 0 : Transmit Channels 1 to 32 Gapped Clock Channel Select Bits (CH1 to CH32)  
0 = no clock is present on TCHMRK during this channel time  
1 = output a clock on TCHMRK during this channel time. The clock will be synchronous with TCLK.  
* Note that TGCCS4 has two functions:  
When 2.048MHz backplane mode is selected, this register allows the user to enable the 'gapped' clock on  
TCHMRK for any of the 32 possible backplane channels.  
When 1.544MHz backplane mode is selected, the LSB of this register determines whether or not a clock is  
generated on TCHMRK during the F-Bit time:  
TGCCS4.0 = 0, do not generate a clock during the F-Bit  
TGCCS4.0 = 1, generate a clock during the F-Bit  
In this mode, TGCCS4.1 to TGCCS4.7 should be set to 0.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.11 T1 Transmit Bit Oriented Code (BOC) Controller  
The DS26556 contains a BOC generator on the transmit side and a BOC detector on the receive side. The BOC  
function is available only in T1 mode.  
Bits 0 through 5 in the TBOC register contain the BOC message to be transmitted. Setting SBOC = 1 (THC2.6)  
causes the transmit BOC controller to immediately begin inserting the BOC sequence into the FDL bit position. The  
transmit BOC controller automatically provides the abort sequence. BOC messages will be transmitted as long as  
SBOC is set. Note that the TFPT (TCR1.6) control bit must be set to 'zero' for the BOC message to overwrite F-bit  
information being sampled on TSER.  
To Transmit a BOC  
1) Write 6-bit code into the TBOC register.  
2) Set SBOC bit in THC2 = 1.  
Register Name:  
Register Description:  
Address (hex):  
TBOC  
Transmit BOC Register  
163h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
—-  
0
6
0
5
TBOC5  
0
4
TBOC4  
0
3
2
1
TBOC1  
0
0
TBOC0  
0
TBOC3 TBOC2  
0
0
Bits 7 & 6 : Unused, must be set = 0 for proper operation.  
Bit 5 : Transmit BOC Bit 5 (TBOC5) MSB of the Transmit BOC Code.  
Bit 4 : Transmit BOC Bit 4 (TBOC4)  
Bit 3 : Transmit BOC Bit 3 (TBOC3)  
Bit 2 : Transmit BOC Bit 2 (TBOC2)  
Bit 1 : Transmit BOC Bit 1 (TBOC1)  
Bit 0 : Transmit BOC Bit 0 (TBOC0). LSB of the Transmit BOC Code.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.12 T1 Transmit FDL  
Register Name:  
Register Description:  
Address (hex):  
TFDL  
Transmit FDL Register  
162h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
TFDL7  
0
6
TFDL6  
0
5
TFDL5  
0
4
TFDL4  
1
3
TFDL3  
1
2
TFDL2  
1
1
TFDL1  
0
0
TFDL0  
0
Note: Also used to insert Fs framing pattern in D4 framing mode.  
The Transmit FDL Register (TFDL) contains the Facility Data Link (FDL) information that is to be inserted on a byte  
basis into the outgoing T1 data stream. The LSB is transmitted first. In D4 mode, only the lower six bits are used.  
Bit 7 : Transmit FDL Bit 7 (TFDL7) MSB of the Transmit FDL Code.  
Bit 6 : Transmit FDL Bit 6 (TFDL6)  
Bit 5 : Transmit FDL Bit 5 (TFDL5)  
Bit 4 : Transmit FDL Bit 4 (TFDL4)  
Bit 3 : Transmit FDL Bit 3 (TFDL3)  
Bit 2 : Transmit FDL Bit 2 (TFDL2)  
Bit 1 : Transmit FDL Bit 1 (TFDL1)  
Bit 0 : Transmit FDL Bit 0 (TFDL0) LSB of the Transmit FDL Code.  
11.5.13 Transmit SLC–96 Operation  
Register Name:  
Register Description:  
Address (hex):  
TSLC1, TSLC2, TSLC3  
Transmit SLC96 Data Link Registers  
164h, 165h, 166h [+ (200h x n) : where n = 0 to 3, for Ports 1 to 4]  
(MSB)  
(LSB)  
C8  
M2  
S = 1  
C7  
M1  
S4  
C6  
S = 0  
S3  
C5  
S = 1  
S2  
C4  
S = 0  
S1  
C3  
C11  
A2  
C2  
C10  
A1  
C1  
C9  
M3  
TSLC1  
TSLC2  
TSLC3  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.14 Transmit HDLC Controller  
Register Name:  
Register Description:  
Address (hex):  
THC1  
Transmit HDLC Control Register 1  
110h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
NOFS  
0
6
TEOML  
0
5
THR  
0
4
THMS  
0
3
TFS  
0
2
TEOM  
0
1
TZSD  
0
0
TCRCD  
0
Bit 7 : Number of Flags Select (NOFS)  
0 = send one flag between consecutive messages  
1 = send two flags between consecutive messages  
Bit 6 : Transmit End of Message and Loop (TEOML) To loop on a message, should be set to a one just before  
the last data byte of an HDLC packet is written into the transmit FIFO. The message will repeat until the user  
clears this bit or a new message is written to the transmit FIFO. If the host clears the bit, the looping message will  
complete then flags will be transmitted until new message is written to the FIFO. If the host terminates the loop by  
writing a new message to the FIFO the loop will terminate, one or two flags will be transmitted and the new  
message will start. If not disabled via TCRCD, the transmitter will automatically append a 2-byte CRC code to the  
end of all messages.  
Bit 5 : Transmit HDLC Reset (THR) Will reset the transmit HDLC controller and flush the transmit FIFO. An abort  
followed by 7Eh or FFh flags/idle will be transmitted until a new packet is initiated by writing new data into the  
FIFO. Must be cleared and set again for a subsequent reset.  
0 = Normal operation  
1 = Reset transmit HDLC controller and flush the transmit FIFO  
Bit 4 : Transmit HDLC Mapping Select (THMS)  
0 = Transmit HDLC assigned to channels  
1 = Transmit HDLC assigned to FDL(T1 mode), Sa Bits(E1 mode)  
Bit 3 : Transmit Flag/Idle Select (TFS) This bit selects the inter-message fill character after the closing and  
before the opening flags (7Eh).  
0 = 7Eh  
1 = FFh  
Bit 2 : Transmit End of Message (TEOM) Should be set to a one just before the last data byte of an HDLC packet  
is written into the transmit FIFO at THF. If not disabled via TCRCD, the transmitter will automatically append a 2-  
byte CRC code to the end of the message.  
Bit 1 : Transmit Zero Stuffer Defeat (TZSD) The Zero Stuffer function automatically inserts a zero in the  
message field (between the flags) after 5 consecutive ones to prevent the emulation of a flag or abort sequence by  
the data pattern. The receiver automatically removes (de-stuffs) any zero after 5 ones in the message field.  
0 = enable the zero stuffer (normal operation)  
1 = disable the zero stuffer  
Bit 0 : Transmit CRC Defeat (TCRCD) A 2-byte CRC code is automatically appended to the outbound message.  
This bit can be used to disable the CRC function.  
0 = enable CRC generation (normal operation)  
1 = disable CRC generation  
242 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THC2  
Transmit HDLC Control Register 2  
113h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
TABT  
0
6
SBOC  
0
5
4
THCS4  
0
3
THCS3  
0
2
THCS2  
0
1
THCS1  
0
0
THCS0  
0
THCEN  
0
Bit 7 : Transmit Abort (TABT) A 0-to-1 transition will cause the FIFO contents to be dumped and one FEh abort  
to be sent followed by 7Eh or FFh flags/idle until a new packet is initiated by writing new data into the FIFO. Must  
be cleared and set again for a subsequent abort to be sent.  
Bit 6 : Send BOC (SBOC) Set = 1 to transmit the BOC code placed in bits 0 to 5 of the TBOC register.  
Bit 5 : Transmit HDLC Controller Enable (THCEN)  
0 = Transmit HDLC Controller is not enabled  
1 = Transmit HDLC Controller is enabled  
Bits 4 to 0 : Transmit HDLC Channel Select (THCS0 to 4). Determines which DSO channel will carry the HDLC  
message if enabled.  
Register Name:  
Register Description:  
Address (hex):  
THBSE  
Transmit HDLC Bit Suppress  
111h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
TBSE8  
0
6
TBSE7  
0
5
TBSE6  
0
4
TBSE5  
0
3
TBSE4  
0
2
TBSE3  
0
1
TBSE2  
0
0
TBSE1  
0
Bit 7 : Transmit Bit 8 Suppress (TBSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Transmit Bit 7 Suppress (TBSE7) Set to one to stop this bit from being used.  
Bit 5 : Transmit Bit 6 Suppress (TBSE6) Set to one to stop this bit from being used.  
Bit 4 : Transmit Bit 5 Suppress (TBSE5) Set to one to stop this bit from being used.  
Bit 3 : Transmit Bit 4 Suppress (TBSE4) Set to one to stop this bit from being used.  
Bit 2 : Transmit Bit 3 Suppress (TBSE3) Set to one to stop this bit from being used.  
Bit 1 : Transmit Bit 2 Suppress (TBSE2) Set to one to stop this bit from being used.  
Bit 0 : Transmit Bit 1 Suppress (TBSE1) LSB of the channel. Set to one to stop this bit from being used.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.14.1Transmit HDLC FIFO Control  
Register Name:  
Register Description:  
Address (hex):  
THFC  
Transmit HDLC FIFO Control Register  
187h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
TFLWM1 TFLWM0  
0
0
Bits 7 to 2 : Unused. Must be set = 0 for proper operation.  
Bits 1 to 0 : Transmit HDLC FIFO Low Watermark Select (TFLWM0 to TFLWM1)  
TFLWM1  
TFLWM0  
Transmit FIFO Watermark  
4 bytes  
0
0
1
1
0
1
0
1
16 bytes  
32 bytes  
48 bytes  
11.5.14.2HDLC Status and Information  
TLS2 provides status information for the transmit HDLC controller. When a particular event has occurred (or is  
occurring), the appropriate bit in one of these registers will be set to a one. Some of the bits in these registers are  
latched and some are real time bits that are not latched. This section contains register descriptions that list which  
bits are latched and which are real time. With the latched bits, when an event occurs and a bit is set to a one, it will  
remain set until the user reads that bit. The bit will be cleared when it is read and it will not be set again until the  
event has occurred again. The real time bits report the current instantaneous conditions that are occurring and the  
history of these bits is not latched.  
Like the other latched status registers, the user will follow a read of the status bit with a write. The byte written to  
the register will inform the device which of the latched bits the user wishes to clear (the real-time bits are not  
affected by writing to the status register). The user will write a byte to one of these registers, with a one in the bit  
positions he or she wishes to clear and a zero in the bit positions he or she does not wish to clear.  
The HDLC status register, TLS2 has the ability to initiate a hardware interrupt via the INT output signal. Each of the  
events in this register can be either masked or unmasked from the interrupt pin via the receive HDLC Interrupt  
Mask Register (TIM2). Interrupts will force the INT signal low when the event occurs. The INT pin will be allowed to  
return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TRTS2  
Transmit Real-Time Status Register 2 (HDLC)  
1B1h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
TEMPTY  
0
2
TFULL  
0
1
TLWM  
0
0
TNF  
0
All bits in this register are real time.  
Bits 7 to 4: Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit FIFO Empty (TEMPTY) A real-time bit that is set high when the FIFO is empty.  
Bit 2 : Transmit FIFO Full (TFULL) A real-time bit that is set high when the FIFO is full.  
Bit 1 : Transmit FIFO Below Low Watermark Condition (TLWM) Set when the transmit 64-byte FIFO empties  
beyond the low watermark as defined by the Transmit Low Watermark Bits (TLWM).  
Bit 0 : Transmit FIFO Not Full Condition (TNF) Set when the transmit 64-byte FIFO has at least 1 byte available.  
245 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TLS2  
Transmit Latched Status Register 2 (HDLC)  
191h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
TFDLE  
0
3
TUDR  
0
2
TMEND  
0
1
TLWMS  
0
0
TNFS  
0
All bits in this register are latched and can create interrupts.  
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Transmit FDL Register Empty (TFDLE) Set when the TFDL register has shifted out all 8 bits. Useful if the  
user wants to manually use the TFDL register to send messages, instead of using the HDLC or BOC controller  
circuits.  
Bit 3 : Transmit FIFO Underrun Event (TUDR) Set when the transmit FIFO empties out without having seen the  
TMEND bit set. An abort is automatically sent.  
Bit 2 : Transmit Message End Event (TMEND) Set when the transmit HDLC controller has finished sending a  
message.  
Bit 1 : Transmit FIFO Below Low Watermark Set Condition (TLWMS) Set when the transmit 64-byte FIFO  
empties beyond the low watermark as defined by the Transmit Low Watermark Bits (TLWM) (rising edge detect of  
TLWM).  
Bit 0 : Transmit FIFO Not Full Set Condition (TNFS) Set when the transmit 64–byte FIFO has at least one empty  
byte available for write. Rising edge detect of TNF. Indicates change of state from full to not full.  
246 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIM2  
Transmit Interrupt Mask Register 2  
1A1h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
TFDLE  
0
3
2
1
TLWMS  
0
0
TNFS  
0
TUDR TMEND  
0
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Transmit FDL Register Empty (TFDLE)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Transmit FIFO Underrun Event (TUDR)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Transmit Message End Event (TMEND)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Transmit FIFO Below Low Watermark Set Condition (TLWMS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Transmit FIFO Not Full Set Condition (TNFS)  
0 = interrupt masked  
1 = interrupt enabled  
11.5.14.3FIFO Information  
The Transmit FIFO Buffer Available register indicates the number of bytes that can be written into the transmit  
FIFO. The count from this register informs the host as to how many bytes can be written into the transmit FIFO  
without overflowing the buffer. This is a real-time register. The count shall remain valid and stable during the read  
cycle.  
Register Name:  
Register Description:  
Address (hex):  
TFBA  
Transmit HDLC FIFO Buffer Available  
1B3h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
TFBA6  
0
5
TFBA5  
0
4
TFBA4  
0
3
2
1
TFBA1  
0
0
TFBA0  
0
TFBA3 TFBA2  
0
0
Bits 0 to 6 : Transmit FIFO Bytes Available (TFBAO to TFBA6) TFBA0 is the LSB.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
THF  
Register Description:  
Address (hex):  
Transmit HDLC FIFO  
1B4h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
THD7  
0
6
THD6  
0
5
THD5  
0
4
THD4  
0
3
THD3  
0
2
THD2  
0
1
THD1  
0
0
THD0  
0
Bit 7 : Transmit HDLC Data Bit 7 (THD7) MSB of a HDLC packet data byte.  
Bit 6 : Transmit HDLC Data Bit 6 (THD6)  
Bit 5 : Transmit HDLC Data Bit 5 (THD5)  
Bit 4 : Transmit HDLC Data Bit 4 (THD4)  
Bit 3 : Transmit HDLC Data Bit 3 (THD3)  
Bit 2 : Transmit HDLC Data Bit 2 (THD2)  
Bit 1 : Transmit HDLC Data Bit 1 (THD1)  
Bit 0 : Transmit HDLC Data Bit 0 (THD0) LSB of a HDLC packet data byte.  
11.5.15 Programmable In-Band Loop-Code Generator  
This register definition is repeated here for convenience.  
Register Name:  
Register Description:  
Address (hex):  
TCR4  
Transmit Control Register 4  
186h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
TRAIM  
0
2
TAISM  
0
1
TC1  
0
0
TC0  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit RAI Mode (TRAIM) Determines the pattern sent when TRAI (TCR1.0) is activated in ESF frame  
mode only.  
0 = transmit normal RAI upon activation with TCR1.0  
1 = transmit RAI-CI (T1.403) upon activation with TCR1.0  
Bit 2 : Transmit AIS Mode (TAISM) Determines the pattern sent when TAIS (TCR1.1) is activated.  
0 = transmit normal AIS (unframed all ones) upon activation with TCR1.1  
1 = transmit AIS-CI (T1.403) upon activation with TCR1.1  
Bits 1 to 0 : Transmit Code Length Definition Bits (TC0 to TC1)  
TC1  
TC0  
LENGTH SELECTED (BITS)  
0
0
5
0
1
1
0
6/3  
7
1
1
16/8/4/2/1  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCD1  
Transmit Code Definition Register 1  
1ACh + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bit 7 : Transmit Code Definition Bit 7 (C7) First bit of the repeating pattern.  
Bit 6 : Transmit Code Definition Bit 6 (C6)  
Bit 5 : Transmit Code Definition Bit 5 (C5)  
Bit 4 : Transmit Code Definition Bit 4 (C4)  
Bit 3 : Transmit Code Definition Bit 3 (C3)  
Bit 2 : Transmit Code Definition Bit 2 (C2) A Don’t Care if a 5-bit length is selected.  
Bit 1 : Transmit Code Definition Bit 1 (C1) A Don’t Care if a 5- or 6-bit length is selected.  
Bit 0 : Transmit Code Definition Bit 0 (C0) A Don’t Care if a 5-, 6-, or 7-bit length is selected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCD2  
Transmit Code Definition Register 2  
1ADh + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bits 0 to 7 : Transmit Code Definition Bit 0 to 7 (C0 to C7) A Don’t Care if a 5-, 6-, or 7-bit length is selected.  
11.5.16 Interfacing the T1 Tx Formatter to the BERT  
Register Name:  
Register Description:  
Address (hex):  
TBICR  
Transmit BERT Interface Control Register  
18Ah + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
TBDC  
0
1
TBFUS  
0
0
TBEN  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Transmit BERT Direction Control (TBDC)  
0 = Transmit Path: The BERT transmits toward the network.  
1 = Backplane: The BERT transmits toward the system backplane.  
Bit 1 : Transmit BERT Framed/Unframed Select (TBFUS)  
0 = The framer will not provide data from the F-bit position (framed)  
1 = The framer will clock data from the F-bit position (unframed)  
Bit 0 : Transmit BERT Enable (TBEN)  
0 = Transmit BERT is disabled.  
1 = Transmit BERT is enabled.  
Register Name:  
Register Description:  
Address (hex):  
TBCS1, TBCS2, TBCS3  
Transmit BERT Channel Select Registers  
0D4h, 0D5h, 0D6h [+ (200h x n) : where n = 0 to 3, for Ports 1 to 4]  
Setting any of the CH1 through CH24 bits in the TBCS1 through TBCS3 registers will map data from those  
channels to the on-board BERT. TBEN must be set to one for these registers to function. Multiple, or all channels  
may be selected simultaneously. These registers affect the transmit-side framer only.  
(MSB)  
CH8  
CH16  
CH24  
(LSB)  
CH1  
CH9  
CH7  
CH15  
CH23  
CH6  
CH14  
CH22  
CH5  
CH13  
CH21  
CH4  
CH12  
CH20  
CH3  
CH11  
CH19  
CH2  
CH10  
CH18  
TBCS1  
TBCS2  
TBCS3  
CH17  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TBBS  
Transmit BERT Bit Suppress Register  
18Bh  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 7 : Transmit Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Transmit Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 5 : Transmit Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 4 : Transmit Channel Bit 5 Suppress (BSE5) Set to one to stop this bit from being used.  
Bit 3 : Transmit Channel Bit 4 Suppress (BSE4) Set to one to stop this bit from being used.  
Bit 2 : Transmit Channel Bit 3 Suppress (BSE3) Set to one to stop this bit from being used.  
Bit 1 : Transmit Channel Bit 2 Suppress (BSE2) Set to one to stop this bit from being used.  
Bit 0 : Transmit Channel Bit 1 Suppress (BSE1) LSB of the channel. Set to one to stop this bit from being used.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.5.17 T1 Transmit Synchronizer  
When enabled, the DS26556 transmitter has the ability to identify the D4 or ESF frame boundary within the  
incoming NRZ data stream at TSER. The TFM (TCR3.2) control bit determines whether the transmit synchronizer  
searches for the D4 or ESF multiframe. Additional control signals for the transmit synchronizer are located in the  
TSYNCC register. The Transmit Latched Status 3 (TLS3) register provides a latched status bit (LOFD) to indicate  
that a Loss-of-Frame synchronization has occurred, and a real-time bit (LOF) which is set high when the  
synchronizer is searching for frame/multiframe alignment. The LOFD bit can be enabled to cause an interrupt  
condition on INT.  
Note that when the transmit synchronizer is used, the TSYNC signal should be set as an output (TSIO = 1) and the  
recovered frame sync pulse will be output on this signal. The recovered multiframe sync pulse will be output if  
enabled with TIOCR.0 (TSM = 1).  
Register Name:  
Register Description:  
Address (hex):  
TSYNCC  
Transmit Synchronizer Control Register  
18Eh + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
TSEN  
0
1
0
SYNCE RESYNC  
0
0
Bits 7 to 3: Unused. Must be set = 0 for proper operation.  
Bit 2 : Transmit Synchronizer Enable (TSEN)  
0 = Transmit Synchronizer Disabled  
1 = Transmit Synchronizer Enabled  
Bit 1 : Sync Enable (SYNCE)  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 0 : Resynchronize (RESYNC)  
When toggled from low to high, a resynchronization of the transmit side framer is initiated. Must be cleared  
and set again for a subsequent resync.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TLS3  
Transmit Latched Status Register 3 (Synchronizer)  
192h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
LOF  
0
0
LOFD  
0
Bits 7 to 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : Loss of Frame (LOF) A real-time bit that indicates that the transmit synchronizer is searching for the sync  
pattern in the incoming data stream.  
Bit 0 : Loss Of Frame Synchronization Detect (LOFD) This latched bit is set when the transmit synchronizer is  
searching for the sync pattern in the incoming data stream.  
Register Name:  
Register Description:  
Address (hex):  
TIM3  
Transmit Interrupt Mask Register 3 (Synchronizer)  
1A2h + (200h x n) : where n = 0 to 3, for Ports 1 to 4  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
LOFD  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Loss Of Frame Synchronization Detect (LOFD)  
0 = Interrupt Masked  
1 = Interrupt Enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6 E1 Receive Framer  
Table 11-15 E1 Receive Framer Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
NAME  
FUNCTION  
PORT 3 + 400h  
PORT 4 + 600h  
0000-000F  
0010  
0011  
0012  
0013  
0014-001F  
0020  
0021  
0022  
0023  
0024  
0025  
0026  
0027  
0028  
0029  
002A  
002B  
002C  
002D  
002E  
002F  
0030  
0031  
0032  
0033  
0034  
0035  
0036  
0037  
0038  
0039  
003A  
003B  
003C  
003D  
003E  
003F  
0040  
0041  
0042  
0043  
0044  
0045  
0046  
0047  
RHC  
RHBSE  
RDS0SEL  
RSIGC  
Unused. Must be set = 0 for proper operation  
Rx HDLC Control  
Rx HDLC Bit Suppress  
Rx DS0 Monitor Select  
Rx Signaling Control  
Unused. Must be set = 0 for proper operation  
Rx Idle Definition 1  
Rx Idle Definition 2  
Rx Idle Definition 3  
Rx Idle Definition 4  
Rx Idle Definition 5  
Rx Idle Definition 6  
Rx Idle Definition 7  
Rx Idle Definition 8  
Rx Idle Definition 9  
Rx Idle Definition 10  
Rx Idle Definition 11  
Rx Idle Definition 12  
Rx Idle Definition 13  
Rx Idle Definition 14  
Rx Idle Definition 15  
Rx Idle Definition 16  
Rx Idle Definition 17  
Rx Idle Definition 18  
Rx Idle Definition 19  
Rx Idle Definition 20  
Rx Idle Definition 21  
Rx Idle Definition 22  
Rx Idle Definition 23  
Rx Idle Definition 24  
Rx Idle Definition 25  
Rx Idle Definition 26  
Rx Idle Definition 27  
Rx Idle Definition 28  
Rx Idle Definition 29  
Rx Idle Definition 30  
Rx Idle Definition 31  
Rx Idle Definition 32  
Rx Signaling 1  
RIDR1  
RIDR2  
RIDR3  
RIDR4  
RIDR5  
RIDR6  
RIDR7  
RIDR8  
RIDR9  
RIDR10  
RIDR11  
RIDR12  
RIDR13  
RIDR14  
RIDR15  
RIDR16  
RIDR17  
RIDR18  
RIDR19  
RIDR20  
RIDR21  
RIDR22  
RIDR23  
RIDR24  
RIDR25  
RIDR26  
RIDR27  
RIDR28  
RIDR29  
RIDR30  
RIDR31  
RIDR32  
RS1  
RS2  
RS3  
RS4  
RS5  
RS6  
RS7  
RS8  
Rx Signaling 2  
Rx Signaling 3  
Rx Signaling 4  
Rx Signaling 5  
Rx Signaling 6  
Rx Signaling 7  
Rx Signaling 8  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0048  
NAME  
FUNCTION  
RS9  
RS10  
RS11  
RS12  
RS13  
RS14  
RS15  
RS16  
LCVCR1  
LCVCR2  
PCVCR1  
PCVCR2  
FOSCR1  
FOSCR2  
EBCR1  
EBCR2  
Rx Signaling 9  
Rx Signaling 10  
Rx Signaling 11  
Rx Signaling 12  
Rx Signaling 13  
Rx Signaling 14  
Rx Signaling 15  
Rx Signaling 16  
0049  
004A  
004B  
004C  
004D  
004E  
004F  
0050  
0051  
0052  
0053  
0054  
0055  
0056  
0057  
Rx Line-Code Violation Counter 1  
Rx Line-Code Violation Counter 2  
Rx Path-Code Violation Counter 1  
Rx Path-Code Violation Counter 2  
Rx Frames Out-of-Sync Counter 1  
Rx Frames Out-of-Sync Counter 2  
Receive E-Bit Counter 1  
Receive E-Bit Counter 2  
0058-005F  
0060  
Unused. Must be set = 0 for proper operation  
Rx DS0 Monitor  
Unused. Must be set = 0 for proper operation  
Receive Real-Time Status 7  
Unused. Must be set = 0 for proper operation  
Receive Align Frame  
RDS0M  
RRTS7  
0061  
0062  
0063  
0064  
RAF  
0065  
0066  
0067  
0068  
0069  
006A  
006B  
006C  
RNAF  
RSiAF  
RSiNAF  
RRA  
RSa4  
RSa5  
RSa6  
RSa7  
RSa8  
RMMR  
RCR1  
RCR2  
RCR3  
RIOCR  
RGCCR  
ERCNT  
RHFC  
-
Receive Non-Align Frame  
Receive Si Bits for Align Frame  
Receive Si Bits for Non-Align Frame  
Receive Remote Alarm Bits  
Receive Sa4 Bits  
Receive Sa5 Bits  
Receive Sa6 Bits  
Receive Sa7 Bits  
Receive Sa8 Bits  
Unused. Must be set = 0 for proper operation  
Rx Master Mode  
Rx Control 1  
Rx Control 2  
Rx Control 3  
006D  
006E-007F  
0080  
0081  
0082  
0083  
0084  
0085  
0086  
0087  
0088  
Rx I/O Configuration  
Rx Gapped Clock Control  
Rx Error Count Configuration  
Rx HDLC FIFO Control  
Unused. Must be set = 0 for proper operation  
Unused. Must be set = 0 for proper operation  
Rx BERT Interface Control  
Rx BERT Bit Suppress Enable  
Unused. Must be set = 0 for proper operation  
Rx Latched Status 1  
Rx Latched Status 2  
Rx Latched Status 3  
Rx Latched Status 4  
Rx Latched Status 5 (HDLC)  
0089  
008A  
008B  
RBICR  
RBBS  
RLS1  
RLS2  
RLS3  
RLS4  
RLS5  
008C – 008F  
0090  
0091  
0092  
0093  
0094  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0095  
NAME  
FUNCTION  
RSS1  
RSS2  
RSS3  
RSS4  
Unused. Must be set = 0 for proper operation.  
0096  
0097  
0098  
0099  
009A  
009B  
009C  
009D  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Rx Signaling Change-of-State Status 1  
Rx Signaling Change-of-State Status 2  
Rx Signaling Change-of-State Status 3  
Rx Signaling Change-of-State Status 4  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Rx Interrupt Information Reg  
RIIR  
009E  
009F  
00A0  
RIM1  
Rx Interrupt Mask Reg 1  
00A1  
RIM2  
Rx Interrupt Mask Reg 2  
00A2  
RIM3  
Rx Interrupt Mask Reg 3  
00A3  
RIM4  
Rx Interrupt Mask Reg 4  
00A4  
00A5  
00A6  
00A7  
00A8  
00A9  
00AA  
00AB  
RIM5  
RSCSE1  
RSCSE2  
RSCSE3  
RSCSE4  
RRTS1  
RRTS3  
Rx Interrupt Mask Reg 5 (HDLC)  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation  
Rx Signaling Change-of-State Enable 1  
Rx Signaling Change-of-State Enable 2  
Rx Signaling Change-of-State Enable 3  
Rx Signaling Change-of-State Enable 4  
Unused. Must be set = 0 for proper operation.  
Rx Real-Time Status 1  
Unused. Must be set = 0 for proper operation.  
Rx Real-Time Status 3  
Unused. Must be set = 0 for proper operation.  
Rx Real-Time Status 5 (HDLC)  
Rx HDLC Packet Bytes Available  
Rx HDLC FIFO  
00AC-00AF  
00B0  
00B1  
00B2  
00B3  
00B4  
00B5  
00B6  
RRTS5  
RHPBA  
RHF  
00B7-00C3  
00C4  
Unused. Must be set = 0 for proper operation.  
Rx Channel Mark 1  
Rx Channel Mark 2  
Rx Channel Mark 3  
Rx Channel Mark 4  
RCMR1  
RCMR2  
RCMR3  
RCMR4  
RSI1  
00C5  
00C6  
00C7  
00C8  
Rx Signaling Insertion 1  
00C9  
RSI2  
Rx Signaling Insertion 2  
00CA  
RSI3  
Rx Signaling Insertion 3  
00CB  
RSI4  
Rx Signaling Insertion 4  
00CC  
00CD  
00CE  
00CF  
00D0  
00D1  
00D2  
00D3  
RGCCS1  
RGCCS2  
RGCCS3  
RGCCS4  
RCICE1  
RCICE2  
RCICE3  
RCICE4  
RBCS1  
RBCS2  
Rx Gapped Clock Channel Select 1  
Rx Gapped Clock Channel Select 2  
Rx Gapped Clock Channel Select 3  
Rx Gapped Clock Channel Select 4  
Rx Channel Idle Code Enable 1  
Rx Channel Idle Code Enable 2  
Rx Channel Idle Code Enable 3  
Rx Channel Idle Code Enable 4  
Rx BERT Channel Select 1  
00D4  
00D5  
Rx BERT Channel Select 2  
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ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
00D6  
NAME  
FUNCTION  
RBCS3  
RBCS4  
Rx BERT Channel Select 3  
Rx BERT Channel Select 4  
Unused. Must be set = 0 for proper operation.  
00D7  
00D8 – 00DF  
11.6.1 E1 Receive Framer Description and Operation  
Four fully independent DS1/E1 framers are included within the DS26556. Each framer can be individually  
programmed to accept AMI, HDB3 (E1), B8ZS (T1), or NRZ data. In E1 mode each framer supports FAS, CRC-4,  
and CAS frame formats, and detects/reports common alarms such as AIS, RAI, LOS, and LOF. Performance  
monitor counters are maintains for each port which report bipolar/line code violations, CRC-4 errors, FAS errors,  
and E-bits.  
Each framer has an HDLC controller which can be mapped into a single time slot, or Sa4 to Sa8 bits (E1 Mode) or  
the FDL (T1 Mode) and includes 64 byte FIFO buffers in both the transmit and receive paths.  
Host interface is simplified with status registers optimized for either interrupt driven or polled environments. In  
many cases, status bits are reported both real-time and latched on change-of-state with separate bits for each  
state change. Most latched bits can be mapped to generate an external interrupt on the INT pin.  
Additional details concerning the operation of the E1 framer are included within the register descriptions within this  
section.  
11.6.2 Receive Master Mode Register  
The Receive Master Mode Register (RMMR) controls the initialization of the receive side framer. The FRM_EN bit  
may be left ‘low’ if the framer for that particular port is not going to be used, putting the circuit in a low-power  
(sleep) state.  
Register Name:  
Register Description:  
Address (hex):  
RMMR  
Receive Master Mode Register  
0080, 0280, 0480, 0680  
Bit #  
Name  
Default  
7
6
5
0
4
0
3
0
2
0
1
SFTRST  
0
0
T1/E1  
0
FRM_EN INIT_DONE  
0
0
Bit 7 : Framer Enable (FRM_EN) This bit must be written with the desired value prior to setting INIT_DONE.  
0 = Framer disabled – held in low power state  
1 = Framer enabled – all features active  
Bit 6 : Initialization Done (INIT_DONE) The host (user) must set this bit once he/she has written the configuration  
registers. The host is required to write or clear all RAM based registers (addresses 00H to 7FH) prior to setting this  
bit. Once INIT_DONE is set, the internal processor will check the FRM_EN bit. If enabled, the internal processor  
continues executing based on the initial configuration.  
Bits 5 to 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : Soft Reset (SFTRST) Level sensitive processor reset. Should be taken high then low to reset and initialize  
the internal processor.  
0 = Normal operation  
1 = Hold the internal RISC in reset. This bit only affects the receive side processor.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Bit 0 : Receiver T1/E1 Mode Select (T1/E1) Sets operating mode for receiver only! This bit must be set to the  
desired state before writing INIT_DONE.  
0 = T1 operation  
1 = E1 operation  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.3 Interrupt Information Registers  
The Interrupt Information Registers provide an indication of which DS26556 Status Registers are generating an  
interrupt. When an interrupt occurs, the host can read RIIR to quickly identify which of the 6 E1 receive status  
registers are causing the interrupt. The Interrupt Information Register bits will clear once the appropriate interrupt  
has been serviced and cleared, as long as no other interrupt condition is present in the associated status register.  
Status bits that have been masked via the Receive Interrupt Mask (RIMx) registers, will also be masked from the  
IIR registers.  
Register Name:  
Register Description:  
Address (hex):  
RIIR  
Receive Interrupt Information Register  
009F, 029F, 049F, 069F  
Bit #  
Name  
Default  
7
0
6
0
5
RLS6  
0
4
RLS5  
0
3
RLS4  
0
2
RLS3  
0
1
RLS2  
0
0
RLS1  
0
11.6.4 E1 Receive Control Registers  
Register Name:  
Register Description:  
Address (hex):  
RCR1  
Receive Control Register 1  
0081, 0281, 0481, 0681  
Bit #  
Name  
Default  
7
0
6
5
4
RG802  
0
3
RCRC4  
0
2
FRC  
0
1
0
RHDB3 RSIGM  
SYNCE RESYNC  
0
0
0
0
Bit 7 : Unused. Must be set = 0 for proper operation.  
Bit 6 : Receive HDB3 Enable (RHDB3)  
0 = HDB3 disabled  
1 = HDB3 enabled  
Bit 5 : Receive Signaling Mode Select (RSIGM)  
0 = CAS signaling mode  
1 = CCS signaling mode  
Bit 4 : Receive G.802 Enable (RG802)  
0 = do not force RCHMRK high during bit 1 of time slot 26  
1 = force RCHMRK high during bit 1 of time slot 26  
Bit 3 : Receive CRC4 Enable (RCRC4)  
0 = CRC4 disabled  
1 = CRC4 enabled  
Bit 2 : Frame Resync Criteria (FRC)  
0 = resync if FAS received in error 3 consecutive times  
1 = resync if FAS or bit 2 of non-FAS is received in error 3 consecutive times  
Bit 1 : Sync Enable (SYNCE)  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 0 : Resynchronize (RESYNC)  
When toggled from low to high, a resynchronization of the receive-side framer is initiated. Must be cleared  
and set again for a subsequent resync.  
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Figure 11-2 E1 Sync/Resync Criteria  
FRAME OR  
MULTIFRAME  
LEVEL  
SYNC CRITERIA  
RESYNC CRITERIA  
ITU SPEC.  
Three consecutive incorrect  
FAS received  
FAS present in frame N and N  
+ 2, and FAS not present in  
frame N + 1  
G.706  
4.1.1 and 4.1.2  
Alternate: (RCR1.2 = 1) The  
above criteria is met or three  
consecutive incorrect bit 2 of  
non-FAS received  
FAS  
Two valid MF alignment words  
found within 8 ms  
915 or more CRC4 code words  
out of 1000 received in error  
G.706  
4.2 and 4.3.2  
CRC4  
Valid MF alignment word  
found.  
Two consecutive MF alignment  
words received in error or for a  
period of 1 multiframe, all the  
bits in time slot 16 are zero.  
Alternate: (RSIGC.4 = 1)  
CAS  
G.732 5.2  
Valid MF alignment word found Alternate: (RSIGC.4 = 1) The  
and previous time slot 16  
contains code other than all  
zeros.  
above criteria are met or 1  
multiframe is received with all  
bits in time slot 16 set to 0.  
Register Name:  
Register Description:  
Address (hex):  
RCR2  
Receive Control Register 2  
0082, 0282, 0482, 0682  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
RLOSA  
0
Bits 7 to 1: Unused. Must be set = 0 for proper operation.  
Bit 0 : Receive Loss of Signal Alternate Criteria (RLOSA) Defines the criteria for an LOS condition.  
0 = LOS declared upon 255 consecutive zeros (125μs)  
1 = LOS declared upon 2048 consecutive zeros (1ms)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RCR3  
Receive Control Register 3  
0083, 0283, 0483, 0683  
Bit #  
Name  
Default  
7
IDF  
0
6
5
RSERC  
0
4
0
3
0
2
RLB  
0
1
PLB  
0
0
FLB  
0
0
Bit 7 : Input Data Format (IDF)  
0 = Bipolar data is expected at RPOS and RNEG (either AMI or B8ZS)  
1 = NRZ data is expected at RPOS. The BPV counter will be disabled and RNEG will be ignored by the  
DS26556.  
Bit 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : RSER Control (RSERC)  
0 = allow RSER to output data as received under all conditions (normal operation)  
1 = force RSER to one under loss of frame alignment conditions  
Bits 4 & 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Remote Loopback (RLB)  
0 = loopback disabled  
1 = loopback enabled  
Bit 1 : Payload Loopback (PLB)  
0 = loopback disabled  
1 = loopback enabled  
When PLB is enabled, the following will occur:  
1) Data will be transmitted at the TTIP and TRING pins synchronous with RCLK instead of TCLK  
2) All of the receive side signals will continue to operate normally  
3) The TCHMKR signal is forced low  
4) Data at the TDATAI pin is ignored  
Normally, this loopback is only enabled when ESF framing is being performed but can be enabled also in D4  
framing applications. In a PLB situation, the DS26556 will loop the 192 bits of payload data (with BPVs  
corrected) from the receive section back to the transmit section. The FPS framing pattern, CRC6 calculation,  
and the FDL bits are not looped back, they are reinserted by the DS26556.  
In this loopback, data input via the RTIP and RRING pins will be transmitted back to the TTIP and TRING pins.  
Data will continue to pass through the receive side framer of the DS26556 as it would normally and the data  
from the transmit side formatter will be ignored.  
Bit 0 : Framer Loopback (FLB)  
0 = loopback disabled  
1 = loopback enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
This loopback is useful in testing and debugging applications. In FLB, the DS26556 will loop data from the transmit  
side back to the receive side. When FLB is enabled, the following will occur:  
1) (T1 mode) an unframed all one’s code will be transmitted at TTIP and TRING  
(E1 mode) normal data will be transmitted at TTIP and TRING  
2) Data at RPOS and RNEG will be ignored  
3) All receive side signals will take on timing synchronous with TCLK instead of RCLK.  
Please note that it is not acceptable to have RCLK tied to TCLK during this loopback because this will cause  
an unstable condition.  
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Register Name:  
Register Description:  
Address (hex):  
RIOCR  
Receive I/O Configuration Register  
0084, 0284, 0484, 0684  
Bit #  
Name  
7
6
5
4
3
0
2
-
1
0
RCLKIN  
RSYNCINV H100EN HSCLKM  
RSMS2 RSMS1  
V
0
Default  
0
0
0
0
0
0
Bit 7 : RCLK Invert (RCLKINV)  
0 = No inversion  
1 = Invert RCLK input  
Bit 6 : RSYNC Invert (RSYNCINV)  
0 = No inversion  
1 = Invert RSYNC as either input or output  
Bit 5 : H.100 SYNC Mode (H100EN). See Section 8.6.1.  
0 = Normal operation  
1 = HSSYNC shifted  
Bit 4 : HSYSCLK Mode Select (RSCLKM)  
0 = if HSYSCLK is 1.544MHz  
1 = if HSYSCLK is 2.048MHz  
Bits 3 & 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : RSYNC Mode Select 2 (RSMS2)  
T1: RSYNC pin must be programmed in the output frame mode  
0 = do not pulse double wide in signaling frames  
1 = do pulse double wide in signaling frames  
E1: RSYNC pin must be programmed in the output multiframe mode  
0 = RSYNC outputs CAS multiframe boundaries  
1 = RSYNC outputs CRC4 multiframe boundaries  
Bit 0 : RSYNC Mode Select 1 (RSMS1) Selects frame or multiframe pulse at RSYNC pin.  
0 = frame mode  
1 = multiframe mode  
11.6.5 E1 Receive Status and Information  
When a particular event has occurred (or is occurring), the appropriate bit in one of these registers will be set to a  
one. Status bits may operate in either a latched or real-time fashion. Some latched bits may be enabled to  
generate a hardware interrupt via the INT signal.  
Real-Time Bits  
Some status bits operate in a real-time fashion. These bits are read-only and indicate the present state of an alarm  
or a condition. Real-time bits remain stable and valid during the host read operation. The current value of the  
internal status signals can be read at any time from the real time status registers without changing any the latched  
status register bits  
Latched Bits  
When an event or an alarm occurs and a latched bit is set to a one, it will remain set until cleared by the user.  
These bits typically respond on a change-of-state for an alarm, condition, or event; and operate in a read-then-  
write fashion. The user should read the value of the desired status bit, and then write a 1 to that particular bit  
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location in order to clear the latched value (write a 0 to locations not to be cleared). Once the bit is cleared, it will  
not be set again until the event has occurred again.  
Mask Bits  
Some of the alarms and events can be either masked or unmasked from the interrupt pin via the Interrupt Mask  
Registers (RIMx). When unmasked, the INT signal will be forced low when the enabled event or condition occurs.  
The INT pin will be allowed to return high (if no other unmasked interrupts are present) when the user reads then  
clears (with a write) the alarm bit that caused the interrupt to occur. Note that the latched status bit and the INT pin  
will clear even if the alarm is still present.  
Note that some conditions may have multiple status indications. For example, Receive Loss of Frame (RLOF)  
provides the following indications:  
Real-time indication that the receiver is not  
RRTS1.0  
(RLOF)  
synchronized with incoming data stream. Read-only  
bit that remains high as long as the condition is  
present.  
Latched indication that the receiver has loss  
synchronization since the bit was last cleared. Bit  
will clear when written by the user, even if the  
condition is still present (rising edge detect of  
RRTS1.0).  
RLS1.0  
(RLOFD)  
Latched indication that the receiver has reacquired  
synchronization since the bit was last cleared. Bit  
will clear when written by the user, even if the  
condition is still present (falling edge detect of  
RRTS1.0).  
RLS1.4  
(RLOFC)  
Table 11-16 E1 Alarm Criteria  
ITU  
SPEC.  
ALARM  
SET CRITERIA  
An RLOF condition exist on power up prior to  
CLEAR CRITERIA  
initial synchronization, when a resync criteria  
has been met, or when a manual resync has  
been initiated via RCR1.0  
RLOF  
RLOS  
255 or 2048 consecutive zeros received as  
determined by RCR2.0  
In 255-bit times, at least 32 ones  
are received  
G.775/G.962  
O.162  
Bit 3 of non-align frame set to one for three  
consecutive occasions  
Bit 3 of non-align frame set to zero  
for three consecutive occasions  
RRAI  
RAIS  
More than two zeros in two frames  
(512 bits)  
Fewer than three zeros in two frames (512 bits)  
O.162  
Bit 6 of time slot 16 in frame 0 has been set for  
two consecutive multiframes  
RDMA  
V52LNK  
2 out of 3 Sa7 bits are zero  
G.965  
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Register Name:  
Register Description:  
Address (hex):  
RRTS1  
Receive Real-Time Status Register 1  
00B0, 02B0, 04B0, 06B0  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
RRAI  
0
2
RAIS  
0
1
RLOS  
0
0
RLOF  
0
All bits in this register are real-time (not latched).  
Bits 7 to 4 : Unused. Must be set = 0 for proper operation  
Bit 3 : Receive Remote Alarm Indication Condition (RRAI) Set when a remote alarm is received at RPOS and  
RNEG.  
Bit 2 : Receive Alarm Indication Signal Condition (RAIS) Set when an unframed all one’s code is received at  
RPOS and RNEG.  
Bit 1 : Receive Loss of Signal Condition (RLOS) Set when 255 (or 2048 if RCR2.0 = 1) consecutive zeros have  
been detected at RPOS and RNEG.  
Bit 0 : Receive Loss of Frame Condition (RLOF) Set when the DS26556 is not synchronized to the received  
data stream.  
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Register Name:  
Register Description:  
Address (hex):  
RLS1  
Receive Latched Status Register 1  
0090, 0290, 0490, 0690  
Bit #  
Name  
Default  
7
RRAIC  
0
6
RAISC  
0
5
4
3
RRAID  
0
2
RAISD  
0
1
0
RLOSC RLOFC  
RLOSD RLOFD  
0
0
0
0
All bits in this register are latched and can create interrupts.  
Bit 7 : Receive Remote Alarm Condition Clear (RRAIC) Change of state indication. Set when a RRAI condition  
has cleared (falling edge detect of RRAI).  
Bit 6 : Receive AIS Condition Clear (RAISC) Change of state indication. Set when a RAIS condition has cleared  
(falling edge detect of RAIS).  
Bit 5 : Receive Loss of Signal Condition Clear (RLOSC) Change of state indication. Set when an RLOS  
condition has cleared (falling edge detect of RLOS).  
Bit 4 : Receive Loss of Frame Condition Clear (RLOFC) Change of state indication. Set when an RLOF  
condition has cleared (falling edge detect of RLOF).  
Bit 3 : Receive Remote Alarm Condition Detect (RRAID) Change of state indication. Set when a remote alarm is  
received at RPOS and RNEG (rising edge detect of RRAI).  
Bit 2 : Receive AIS Condition Detect (RAISD) Change of state indication. Set when an unframed all one’s code  
is received at RPOS and RNEG (rising edge detect of RAIS).  
Bit 1 : Receive Loss of Signal Condition Detect (RLOSD) Change of state indication. Set when 255 (or 2048 if  
RCR2.0 = 1) consecutive zeros have been detected at RPOS and RNEG (rising edge detect of RLOS).  
Bit 0 : Receive Loss of Frame Condition Detect (RLOFD) Change of state indication that the DS26556 has lost  
synchronized to the received data stream (rising edge detect of RLOF).  
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Register Name:  
Register Description:  
Address (hex):  
RIM1  
Receive Interrupt Mask Register 1  
00A0, 02A0, 04A0, 06A0  
Bit #  
Name  
Default  
7
RRAIC  
0
6
RAISC  
0
5
4
3
RRAID  
0
2
RAISD  
0
1
0
RLOSC RLOFC  
RLOSD RLOFD  
0
0
0
0
Bit 7 : Receive Remote Alarm Clear (RRAIC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6 : Receive AIS Clear (RAISC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5 : Receive Loss of Signal Clear (RLOSC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive Loss of Frame Clear (RLOFC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Receive Remote Alarm Detect (RRAID)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive AIS Detect (RAISD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Receive Loss of Signal Detect (RLOSD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Loss of Frame Detect (RLOFD)  
0 = interrupt masked  
1 = interrupt enabled  
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Register Name:  
Register Description:  
Address (hex):  
RLS2  
Receive Latched Status Register 2  
0091, 0291, 0491, 0691  
Bit #  
Name  
Default  
7
0
6
5
4
3
RSA1  
0
2
RSA0  
0
1
RCMF  
0
0
RAF  
0
CRCRC CASRC FASRC  
0
0
0
All bits in this register are latched. Bits 0 to 3 can cause interrupts. There is no associated real-time register.  
Bit 7 : Unused. Must be set = 0 for proper operation.  
Bit 6 : CRC Resync Criteria Met Event (CRCRC) Set when 915/1000 codewords are received in error.  
Bit 5 : CAS Resync Criteria Met Event (CASRC) Set when 2 consecutive CAS MF alignment words are received  
in error.  
Bit 4 : FAS Resync Criteria Met Event (FASRC) Set when 3 consecutive FAS words are received in error.  
Bit 3 : Receive Signaling All Ones Event (RSA1) Set when the contents of time slot 16 contain less than three  
zeros over 16 consecutive frames. This alarm is not disabled in the CCS signaling mode.  
Bit 2 : Receive Signaling All Zeros Event (RSA0) Set when over a full MF, time slot 16 contains all zeros.  
Bit 1 : Receive CRC4 Multiframe Event (RCMF) Set on CRC4 multiframe boundaries; will continue to be set  
every 2ms on an arbitrary boundary if CRC4 is disabled.  
Bit 0 : Receive Align Frame Event (RAF) Set every 250μs at the beginning of align frames. Used to alert the host  
that Si and Sa bits are available in the RAF and RNAF registers.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM2  
Receive Interrupt Mask Register 2  
00A1, 02A1, 04A1, 06A1  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
RSA1  
0
2
RSA0  
0
1
RCMF  
0
0
RAF  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Receive Signaling All Ones Event (RSA1)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive Signaling All Zeros Event (RSA0)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Receive CRC4 Multiframe Event (RCMF)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Align Frame Event (RAF)  
0 = interrupt masked  
1 = interrupt enabled  
Register Name:  
Register Description:  
Address (hex):  
RRTS3  
Receive Real-Time Status Register 3  
00B2, 02B2, 04B2, 06B2  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
LORC  
0
2
0
1
V52LNK  
0
0
RDMA  
0
All bits in this register are real-time (not latched).  
Bits 7 to 4 : Unused.  
Bit 3 : Loss of Receive Clock Condition (LORC) Set when the RCLK pin has not transitioned for one channel  
time.  
Bit 2 : Unused.  
Bit 1 : V5.2 Link Detected Condition (V52LNK) Set on detection of a V5.2 link identification signal. (G.965).  
Bit 0 : Receive Distant MF Alarm Condition (RDMA) Set when bit-6 of time slot 16 in frame 0 has been set for  
two consecutive multiframes. This alarm is not disabled in the CCS signaling mode.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS3  
Receive Latched Status Register 3  
0092, 0292, 0492, 0692  
Bit #  
Name  
Default  
7
LORCC  
0
6
0
5
4
3
2
0
1
0
V52LNKC RDMAC LORCD  
V52LNKD RDMAD  
0
0
0
0
0
All bits in this register are latched and can create interrupts.  
Bit 7 : Loss of Receive Clock Clear (LORCC) Change of state indication. Set when a LORC condition has  
cleared (falling edge detect of LORC).  
Bits 6 : Unused  
.
Bit 5 : V5.2 Link Detected Clear (V52LNKC) Change of state indication. Set when a V52LNK condition has  
cleared (falling edge detect of V52LNK).  
Bit 4 : Receive Distant MF Alarm Clear (RDMAC) Change of state indication. Set when a RDMA condition has  
cleared (falling edge detect of RDMA).  
Bit 3 : Loss of Receive Clock Detect (LORCD) Change of state indication. Set when the RCLK pin has not  
transitioned for one channel time (rising edge detect of LORC).  
Bits 2 : Unused.  
Bit 1 : V5.2 Link Detect (V52LNKD) Change of state indication. Set on detection of a V5.2 link identification  
signal. (G.965). This is the rising edge detect of V52LNK.  
Bit 0 : Receive Distant MF Alarm Detect (RDMAD) Change of state indication. Set when bit 6 of time slot 16 in  
frame 0 has been set for two consecutive multiframes. This alarm is not disabled in the CCS signaling mode. This  
is the rising edge detect of RDMA.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM3  
Receive Interrupt Mask Register 3  
00A2, 02A2, 04A2, 06A2  
Bit #  
Name  
Default  
7
LORCC  
0
6
0
5
4
3
2
0
1
0
V52LNKC RDMAC LORCD  
V52LNKD RDMAD  
0
0
0
0
0
Bit 7 : Loss of Receive Clock Clear (LORCC)  
0 = interrupt masked  
1 = interrupt enabled  
Bits 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : V5.2 Link Detected Clear (V52LNKC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive Distant MF Alarm Clear (RDMAC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Loss of Receive Clock Detect (LORCD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : V5.2 Link Detect (V52LNKD)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Distant MF Alarm Detect (RDMAD)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RRTS7  
Receive Real-Time Status Register 7  
0062, 0262, 0462, 0662  
Bit #  
Name  
Default  
7
CSC5  
0
6
CSC4  
0
5
CSC3  
0
4
CSC2  
0
3
CSC0  
0
2
1
0
CRC4SA CASSA FASSA  
0
0
0
All bits in this register are real-time (not latched).  
Bits 7 to 3 : CRC4 Sync Counter Bits (CSC0 and CSC2 to CSC4) The CRC4 Sync Counter increments each  
time the 8ms CRC4 multiframe search times out. The counter is cleared when the framer has successfully  
obtained synchronization at the CRC4 level. The counter can also be cleared by disabling the CRC4 mode  
(RCR1.3 = 0). This counter is useful for determining the amount of time the framer has been searching for  
synchronization at the CRC4 level. ITU G.706 suggests that if synchronization at the CRC4 level cannot be  
obtained within 400ms, then the search should be abandoned and proper action taken. The CRC4 Sync Counter  
rolls over. CSC0 is the LSB of the 6-bit counter. (Note: The next to LSB is not accessible. CSC1 is omitted to allow  
resolution to >400ms using 5 bits.)  
Bit 2 : CRC4 MF Sync Active (CRC4SA) Set while the synchronizer is searching for the CRC4 MF alignment  
word.  
Bit 1 : CAS MF Sync Active (CASSA) Set while the synchronizer is searching for the CAS MF alignment word.  
Bit 0 : FAS Sync Active (FASSA) Set while the synchronizer is searching for alignment at the FAS level.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS4  
Receive Latched Status Register 4  
0093, 0293, 0493, 0693  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
RSCOS  
0
2
1SEC  
0
1
TIMER  
0
0
RMF  
0
All bits in this register are latched. There is no associated real-time register.  
Bits 7 to 4 : Unused  
Bit 3 : Receive Signaling Change Of State Event (RSCOS) Set when any channel selected by the Receive  
Signaling Change Of State Interrupt Enable registers (RSCSE1 through RSCSE3), changes signaling state.  
Bit 2 : One-Second Timer (1SEC) Set on every one-second interval based on RCLK.  
Bit 1 : Timer Event (TIMER) Follows the error counter update interval as determined by the ECUS bit in the Error  
Counter Configuration Register (ERCNT).  
T1: Set on increments of 1 second or 42ms based on RCLK.  
E1: Set on increments of 1 second or 62.5ms based on RCLK.  
Bit 0 : Receive Multiframe Event (RMF) Set every 2.0ms on receive CAS multiframe boundaries to alert host the  
signaling data is available. Continues to set on an arbitrary 2.0ms boundary when CAS signaling is not enabled.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM4  
Receive Interrupt Mask Register 4  
00A3, 02A3, 04A3, 06A3  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
0
3
RSCOS  
0
2
1SEC  
0
1
TIMER  
0
0
RMF  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Receive Signaling Change Of State Event (RSCOS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : One-Second Timer (1SEC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Timer Event (TIMER)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive Multiframe Event (RMF)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.6 E1 Error Count Registers  
Register Name:  
Register Description:  
Address (hex):  
ERCNT  
Error Counter Configuration Register  
0086, 0286, 0486, 0686  
Bit #  
Name  
Default  
7
1SECS  
0
6
MCUS  
0
5
MECU  
0
4
ECUS  
0
3
EAMS  
0
2
0
1
0
0
LCVCRF  
0
Bit 7 : One-Second Select (1SECS) When timed update is enabled by EAMS, setting this bit for a specific framer  
will allow that framer’s counters to latch on the one-second reference from framer #1. Note that this bit should  
always be clear for framer #1.  
0 = Use internally generated one-second timer.  
1 = Use 1 second timer from framer #1.  
Bit 6 : Manual Counter Update Select (MCUS) When manual update mode is enabled with EAMS, this bit can  
be used to allow the GLCE bit in GCR1 to latch all counters. Useful for synchronously latching counters of multiple  
framers.  
0 = MECU is used to manually latch counters.  
1 = GLCE is used to manually latch counters.  
Bit 5 : Manual Error Counter Update (MECU) When enabled by ERCNT.3, the changing of this bit from a 0 to a 1  
allows the next clock cycle to load the error counter registers with the latest counts and reset the counters. The  
user must wait a minimum of 250μs before reading the error count registers to allow for proper update.  
Bit 4 : Error Counter Update Select (ECUS)  
T1 mode:  
0 = Update error counters once a second  
1 = Update error counters every 42ms (336 frames)  
E1 mode:  
0 = Update error counters once a second  
1 = Update error counters every 62.5ms (500 frames)  
Bit 3 : Error Accumulation Mode Select (EAMS)  
0 = ERCNT.4 determines accumulation time (timed update)  
1 = ERCNT.5 determines accumulation time (manual update)  
Bits 2 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : E1 Line Code Violation Count Register Function Select (LCVCRF)  
0 = do not count excessive zeros  
1 = count excessive zeros  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.6.1 E1 Line Code Violation Count Register (LCVCR)  
Either bipolar violations or code violations can be counted. Bipolar violations are defined as consecutive marks of  
the same polarity. In this mode, if the HDB3 mode is set for the receive side, HDB3 codewords are not counted as  
BPVs. If ERCNT.0 is set, then the LVC counts code violations as defined in ITU O.161. Code violations are defined  
as consecutive bipolar violations of the same polarity. In most applications, the framer should be programmed to  
count BPVs when receiving AMI code and to count CVs when receiving HDB3 code. This counter increments at all  
times and is not disabled by loss of sync conditions. The counter saturates at 65,535 and will not rollover. The bit  
error rate on an E1 line would have to be greater than 10** - 2 before the VCR would saturate. See Table 11-17.  
Table 11-17 E1 Line Code Violation Counting Options  
E1 CODE VIOLATION SELECT  
WHAT IS COUNTED IN THE LCVCRs  
(ERCNT.0)  
0
1
BPVs  
CVs  
Register Name:  
LCVCR1  
Register Description:  
Address (hex):  
Line Code Violation Count Register 1  
0050, 0250, 0450, 0650  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
LCCV8  
0
LCVC15 LCVC14 LCVC13 LCVC12 LCVC11 LCVC10 LCVC9  
0
0
0
0
0
0
0
Bits 7 to 0 : Line Code Violation Counter Bits 15 to 8 (LCVC15 to LCVC8). LCV15 is the MSB of the 16-bit  
code violation count.  
Register Name:  
Register Description:  
Address (hex):  
LCVCR2  
Line Code Violation Count Register 2  
0051, 0251, 0451, 0651  
Bit #  
Name  
Default  
7
LCVC7  
0
6
LCVC6  
0
5
LCVC5  
0
4
LCVC4  
0
3
2
1
LCVC1  
0
0
LCVC0  
0
LCVC3 LCVC2  
0
0
Bits 7 to 0 : Line Code Violation Counter Bits 7 to 0 (LCVC7 to LCVC0) LCV0 is the LSB of the 16-bit code  
violation count.  
11.6.6.2 E1 Path Code Violation Count Register (PCVCR)  
In E1 operation, the Path Code Violation Count register records CRC4 errors. Since the maximum CRC4 count in a  
one-second period is 1000, this counter cannot saturate. The counter is disabled during loss of sync at either the  
FAS or CRC4 level; it will continue to count if loss of multiframe sync occurs at the CAS level.  
The Path Code Violation Count Register 1 (PCVCR1) is the most significant word and PCVCR2 is the least  
significant word of a 16-bit counter that records path violations (PVs).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
PCVCR1  
Path Code Violation Count Register 1  
0052, 0252, 0452, 0652  
Bit #  
7
6
5
4
3
2
1
0
Name  
PCVC15  
PCVC1  
PCVC1  
PCVC1  
PCVC1  
PCVC1  
PCVC9 PCVC8  
4
3
2
1
0
Default  
0
0
0
0
0
0
0
0
Bits 7 to 0 : Path Code Violation Counter Bits 15 to 8 (PCVC15 to PCVC8) PCVC15 is the MSB of the 16-bit  
path code violation count.  
Register Name:  
Register Description:  
Address (hex):  
PCVCR2  
Path Code Violation Count Register 2  
0053, 0253, 0453, 0653  
Bit #  
Name  
Default  
7
PCVC7  
0
6
PCVC6  
0
5
PCVC5  
0
4
PCVC4  
0
3
2
1
PCVC1  
0
0
PCVC0  
0
PCVC3 PCVC2  
0
0
Bits 7 to 0 : Path Code Violation Counter Bits 7 to 0 (PCVC7 to PCVC0) PCVC0 is the LSB of the 16-bit path  
code violation count.  
11.6.6.3 E1 Frames Out-of-Sync Count Register (FOSCR)  
In E1 mode, the FOSCR counts word errors in the Frame Alignment Signal in time slot 0. This counter is disabled  
when RLOF is high. FAS errors will not be counted when the framer is searching for FAS alignment and/or  
synchronization at either the CAS or CRC4 multiframe level. Since the maximum FAS word error count in a one-  
second period is 4000, this counter cannot saturate.  
The Frames Out of Sync Count Register 1 (FOSCR1) is the most significant word and FOSCR2 is the least  
significant word of a 16-bit counter that records frames out of sync.  
Register Name:  
Register Description:  
Address (hex):  
FOSCR1  
Frames Out Of Sync Count Register 1  
0054, 0254, 0454, 0654  
Bit #  
Name  
Default  
7
FOS15  
0
6
FOS14  
0
5
FOS13  
0
4
FOS12  
0
3
2
1
FOS9  
0
0
FOS8  
0
FOS11 FOS10  
0
0
Bits 7 to 0 : Frames Out of Sync Counter Bits 15 to 8 (FOS15 to FOS8) FOS15 is the MSB of the 16-bit frames  
out of sync count.  
Register Name:  
Register Description:  
Address (hex):  
FOSCR2  
Frames Out Of Sync Count Register 2  
0055, 0255, 0455, 0655  
Bit #  
Name  
Default  
7
FOS7  
0
6
FOS6  
0
5
FOS5  
0
4
FOS4  
0
3
FOS3  
0
2
FOS2  
0
1
FOS1  
0
0
FOS0  
0
Bits 7 to 0 : Frames Out of Sync Counter Bits 7 to 0 (FOS7 to FOS0) FOS0 is the LSB of the 16-bit frames out  
of sync count.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.6.4 E-Bit Counter (EBCR)  
This counter is only available in E1 mode. E–bit Count Register 1 (EBCR1) is the most significant word and  
EBCR2 is the least significant word of a 16-bit counter that records Far End Block Errors (FEBE) as reported in the  
first bit of frames 13 and 15 on E1 lines running with CRC4 multiframe. These count registers will increment once  
each time the received E-bit is set to zero. Since the maximum E-bit count in a one second period is 1000, this  
counter cannot saturate. The counter is disabled during loss of sync at either the FAS or CRC4 level; it will  
continue to count if loss of multiframe sync occurs at the CAS level.  
Register Name:  
Register Description:  
Address (hex):  
EBCR1  
E–Bit Count Register 1  
0056, 0256, 0456, 0656  
Bit #  
Name  
Default  
7
EB15  
0
6
EB14  
0
5
EB13  
0
4
EB12  
0
3
EB11  
0
2
EB10  
0
1
EB9  
0
0
EB8  
0
Bits 7 to 0 : E-Bit Counter Bits 15 to 8 (EB15 to EB8) EB15 is the MSB of the 16-bit E-Bit count.  
Register Name:  
Register Description:  
Address (hex):  
EBCR2  
E–Bit Count Register 2  
0057, 0257, 0457, 0657  
Bit #  
Name  
Default  
7
EB7  
0
6
EB6  
0
5
EB5  
0
4
EB4  
0
3
EB3  
0
2
EB2  
0
1
EB1  
0
0
EB0  
0
Bits 7 to 0 : E-Bit Counter Bits 7 to 0 (EB7 to EB0) EB0 is the LSB of the 16-bit E-Bit count.  
11.6.7 DS0 Monitoring Function  
Register Name:  
Register Description:  
Address (hex):  
RDS0SEL  
Receive Channel Monitor Select  
0012, 0212, 0412, 0612  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
RCM4  
0
3
RCM3  
0
2
RCM2  
0
1
RCM1  
0
0
RCM0  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bits 4 to 0 : Receive Channel Monitor Bits (RCM4 to RCM0) RCM0 is the LSB of a 5-bit channel select that  
determines which receive DS0 channel data will appear in the RDS0M register.  
Register Name:  
Register Description:  
Address (hex):  
RDS0M  
Receive DS0 Monitor Register  
0060, 0260, 0460, 0660  
Bit #  
Name  
Default  
7
B1  
0
6
B2  
0
5
B3  
0
4
B4  
0
3
B5  
0
2
B6  
0
1
B7  
0
0
B8  
0
Bits 7 to 0 : Receive DS0 Channel Bits (B1 to B8) Receive channel data that has been selected by the Receive  
Channel Monitor Select Register. B8 is the LSB of the DS0 channel (last bit to be received).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.8 E1 Receive Signaling Operation  
Register Name:  
Register Description:  
Address (hex):  
RSIGC  
Receive Signaling Control Register  
0013, 0213, 0413, 0613  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
CASMS  
0
3
0
2
-
0
1
-
0
0
-
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : CAS Mode Select (CASMS)  
0 = The DS26556 will initiate a resync when two consecutive multiframe alignment signals have  
been received with an error.  
1 = The DS26556 will initiate a resync when two consecutive multiframe alignment signals have  
been received with an error, or 1 multiframe has been received with all the bits in time slot 16  
in state 0. Alignment criteria are met when at least one bit in state 1 is present in the time slot  
16 preceding the multiframe alignment signal first detected (G.732 alternate criteria).  
Bit 3 to 0 : Unused. Must be set = 0 for proper operation.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RS1 to RS16  
Receive Signaling Registers  
0040 to 004F, 0240 to 024F, 0440 to 044F, 0640 to 064F  
The Receive Signaling Registers are frozen and not updated during a loss of sync condition. They contain the most  
recent signaling information before the LOF occurred.  
(MSB)  
0
(LSB)  
0
0
0
X
Y
X
X
RS1  
CH1-A  
CH2-A  
CH3-A  
CH4-A  
CH5-A  
CH6-A  
CH7-A  
CH8-A  
CH9-A  
CH1-B  
CH2-B  
CH3-B  
CH4-B  
CH5-B  
CH6-B  
CH7-B  
CH8-B  
CH9-B  
CH1-C  
CH2-C  
CH3-C  
CH4-C  
CH5-C  
CH6-C  
CH7-C  
CH8-C  
CH9-C  
CH1-D  
CH2-D  
CH3-D  
CH4-D  
CH5-D  
CH6-D  
CH7-D  
CH8-D  
CH9-D  
CH16-A CH16-B CH16-C CH16-D  
CH17-A CH17-B CH17-C CH17-D  
CH18-A CH18-B CH18-C CH18-D  
CH19-A CH19-B CH19-C CH19-D  
CH20-A CH20-B CH20-C CH20-D  
CH21-A CH21-B CH21-C CH21-D  
CH22-A CH22-B CH22-C CH22-D  
CH23-A CH23-B CH23-C CH23-D  
CH24-A CH24-B CH24-C CH24-D  
RS2  
RS3  
RS4  
RS5  
RS6  
RS7  
RS8  
RS9  
RS10  
RS11  
RS12  
RS13  
RS14  
RS15  
RS16  
CH10-A CH10-B CH10-C CH10-D CH25-A CH25-B CH25-C CH25-D  
CH11-A CH11-B CH11-C CH11-D CH26-A CH26-B CH26-C CH26-D  
CH12-A CH12-B CH12-C CH12-D CH27-A CH27-B CH27-C CH27-D  
CH13-A CH13-B CH13-C CH13-D CH28-A CH28-B CH28-C CH28-D  
CH14-A CH14-B CH14-C CH14-D CH29-A CH29-B CH29-C CH29-D  
CH15-A CH15-B CH15-C CH15-D CH30-A CH30-B CH30-C CH30-D  
Register Name:  
Register Description:  
Address (hex):  
RSS1, RSS2, RSS3, RSS4  
Receive Signaling Status Registers  
0098 to 009B, 0298 to 029B, 0498 to 049B, 0698 to 069B  
When a channel’s signaling data changes state, the respective bit in registers RSS1-RSS4 will be set and latched.  
The RSCOS bit (RLSR4.3) will be set if the channel was also enabled by setting the appropriate bit in RSCSE1-4.  
The INT signal will go low if enabled by the interrupt mask bit RIM4.3. The bit will remain set until read. Note that in  
CAS mode, the LSB of RSS1 would typically represent the CAS alignment bits, and the LSB of RSS3 represents  
reserved bits and the distant multiframe alarm.  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1*  
CH9  
CH17*  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RSS1  
RSS2  
RSS3  
RSS4  
Status bits in this register are latched.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
RSCSE1, RSCSE2, RSCSE3, RSCSE4  
Receive Signaling Change of State Enable  
00A8 to 00AB, 02A8 to 02AB, 04A8 to 04AB, 06A8 to 06AB  
Register Name:  
Register Description:  
Address (hex):  
Setting any of the CH1 through CH32 bits in the RSCSE1 through RSCSE4 registers cause RSCOS (RLSR4.3) to  
be set when that channel’s signaling data changes state.  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1*  
CH9  
CH17*  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RSCSE1  
RSCSE2  
RSCSE3  
RSCSE4  
Register Name:  
Register Description:  
Address (hex):  
RSI1, RSI2, RSI3, RSI4  
Receive Signaling Reinsertion Enable Registers  
00C8 to 00CB, 02C8 to 02CB, 04C8 to 04CB, 06C8 to 06CB  
Setting any of the CH1 through CH32 bits in the RSI1 through RSI4 registers cause signaling data to be reinserted  
for the associated channel.  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1  
CH9  
CH17  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RSI1  
RSI2  
RSI3  
RSI4  
11.6.9 E1 Receive Per-Channel Idle Code Insertion  
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive directions. Thirty-  
two Receive Idle Definition Registers (RIDR1-RIDR32) are provided to set the 8-bit idle code for each channel. The  
Receive Channel Idle Code Enable registers (RCICE1-4) are used to enable idle code replacement on a per  
channel basis.  
Register Name:  
Register Description:  
Address (hex):  
RIDR1 to RIDR32  
Receive Idle Code Definition Registers 1 to 32  
0020 to 003F, 0220 to 023F, 0420 to 043F, 0620 to 063F  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bits 7 to 0 : Per-Channel Idle Code Bits (C0 to C7) C0 is the LSB of the Code (this bit is transmitted last).  
Address 20H is for channel 1, address 3FH is for channel 32.  
The Receive Channel Idle Code Enable Registers (RCICE1/2/3/4) are used to determine which of the 32 E1  
channels from the E1 line to the backplane should be overwritten with the code placed in the Receive Idle Code  
Definition Register.  
Register Name:  
Register Description:  
Address (hex):  
RCICE1, RCICE2, RCICE3, RCICE4  
Receive Channel Idle Code Enable Registers  
00D0 to 00D3, 02D0 to 02D3, 04D0 to 04D3, 06D0 to 06D3  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1  
CH9  
CH17  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RCICE1  
RCICE2  
RCICE3  
RCICE4  
Bits 7 to 0 : Receive Channels 1 to 32 Code Insertion Control Bits (CH1 to CH32)  
0 = do not insert data from the Idle Code Array into the receive data stream  
1 = insert data from the Idle Code Array into the receive data stream  
11.6.10 E1 Receive Channel Mark Registers  
The Receive Channel Mark Registers (RCMR1/RCMR2/RCMR3/RCMR4) control the mapping of channels to the  
cell/packet interface and the RCHMRK pin. The RCHMRK signal is internally used to select which channels will be  
mapped to the cell/packet interface. Externally, the signal can be used to multiplex TDM data into channels not  
used by the cell/packet interface. When the appropriate bits are set to 1, the cell/packet function is mapped to that  
channel and externally the RCHMRK pin is held high during the entire corresponding channel time.  
Register Name:  
Register Description:  
Address (hex):  
RCMR1, RCMR2, RCMR3, RCMR4  
Receive-Channel Mark Registers  
00C4 to 00C7, 02C4 to 02C7, 04C4 to 04C7, 06C4 to 06C7  
(MSB)  
(LSB)  
CH8  
CH16  
CH24  
CH32  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH1  
CH9  
CH17  
RCMR1  
RCMR2  
RCMR3  
RCMR4*  
CH26 CH25/Fbit  
Bits 7 to 0 : Receive Channels 32 to 1 Channel Mark Control Bits (CH1 to CH32)  
0 = force the RCHMRK pin to remain low during this channel time  
1 = force the RCHMRK pin high during this channel time  
In T1 mode, the LSB of RCMR4 determines whether or not the RCHMRK signal pulses high during the F-  
bit time:  
RCMR4.0 = 0, do not pulse RCHMRK during the F-bit  
RCMR4.0 = 1, pulse RCHMRK during the F-bit  
In this mode RCMR4.1 to RCMR4.7 should be set to 0.  
11.6.11 Fractional E1 Support (Gapped Clock Mode)  
Register Name:  
Register Description:  
Address (hex):  
RGCCS1, RGCCS2, RGCCS3, RGCCS4  
Receive Gapped Clock Channel Select Registers  
00CC to 00CF, 02CC to 02CF, 04CC to 04CF, 06CC to 06CF  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1  
CH9  
CH17  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RGCCS1  
RGCCS2  
RGCCS3  
RGCCS4  
Bits 7 to 0 : Receive Channels 1 to 32 Gapped Clock Channel Select Bits (CH1 to CH32)  
0 = no clock is present on RCHMRK during this channel time  
1 = force a clock on RCHMRK during this channel time. The clock will be synchronous with RCLK.  
Register Name:  
Register Description:  
Address (hex):  
RGCCR  
Receive Gapped Clock Control Register  
0085, 0285, 0485, 0685  
Bit #  
Name  
Default  
7
RCCF  
0
6
RGCE  
0
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
-
0
Bit 7 : Receive Channel Clock Format (RCCF) This bit controls the function of the RCHMRK pin went it is in the  
channel clock mode and the RGCCR.6 bit is set = 1. Channel clock mode is enabled in the RCHMRK Pin Function  
Select (RPFS) register.  
0 = 64kbps, clock output during all 8 bits  
1 = 56kbps, clock output during 7 MSBs  
Bit 6 :/ Receive Gapped Clock Enable (RGCE) This bit controls the function of the RCHMRK pin went it is in the  
channel clock mode. Channel clock mode is enabled in the RCHMRK Pin Function Select (RPFS) register.  
0 = RCHMRK outputs a pulse during the LSB of each channel time.  
1 = RCHMRK outputs a gapped bit clock as selected by the RGCCS1 through RGCCC4 registers.  
Bits 5 to 0 : Unused. Must be set = 0 for proper operation.  
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11.6.12 Additional Sa-Bit and Si-Bit Receive Operation (E1 Mode)  
Register Name:  
Register Description:  
Address (hex):  
RAF  
Receive Align Frame Register  
0064, 0264, 0464, 0664  
Bit #  
Name  
Default  
7
Si  
0
6
0
0
5
0
0
4
1
0
3
1
0
2
0
0
1
1
0
0
1
0
Bit 7 : International Bit (Si)  
Bit 6 : Frame Alignment Signal Bit (0)  
Bit 5 : Frame Alignment Signal Bit (0)  
Bit 4 : Frame Alignment Signal Bit (1)  
Bit 3 : Frame Alignment Signal Bit (1)  
Bit 2 : Frame Alignment Signal Bit (0)  
Bit 1 : Frame Alignment Signal Bit (1)  
Bit 0 : Frame Alignment Signal Bit (1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RNAF  
Receive Non-Align Frame Register  
0065, 0256, 0456, 0665  
Bit #  
Name  
Default  
7
Si  
0
6
1
0
5
A
0
4
Sa4  
0
3
Sa5  
0
2
Sa6  
0
1
Sa7  
0
0
Sa8  
0
Bit 7 : International Bit (Si)  
Bit 6 : Frame Non-Alignment Signal Bit (1)  
Bit 5 : Remote Alarm (A)  
Bit 4 : Additional Bit 4 (Sa4)  
Bit 3 : Additional Bit 5 (Sa5)  
Bit 2 : Additional Bit 6 (Sa6)  
Bit 1 : Additional Bit 7 (Sa7)  
Bit 0 : Additional Bit 8 (Sa8)  
Register Name:  
Register Description:  
Address (hex):  
RsiAF  
Received Si Bits of the Align Frame  
0066, 0266, 0466, 0666  
Bit #  
Name  
Default  
7
SiF14  
0
6
SiF12  
0
5
SiF10  
0
4
SiF8  
0
3
SiF6  
0
2
SiF4  
0
1
SiF2  
0
0
SiF0  
0
Bit 0 : Si Bit of Frame 0 (SiF0)  
Bit 1 : Si Bit of Frame 2 (SiF2)  
Bit 2 : Si Bit of Frame 4 (SiF4)  
Bit 3 : Si Bit of Frame 6 (SiF6)  
Bit 4 : Si Bit of Frame 8 (SiF8)  
Bit 5 : Si Bit of Frame 10 (SiF10)  
Bit 6 : Si Bit of Frame 12 (SiF12)  
Bit 7 : Si Bit of Frame 14 (SiF14)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSiNAF  
Received Si Bits of the Non-Align Frame  
0067, 0267, 0467, 0667  
Bit #  
Name  
Default  
7
SiF15  
0
6
SiF13  
0
5
SiF11  
0
4
SiF9  
0
3
SiF7  
0
2
SiF5  
0
1
SiF3  
0
0
SiF1  
0
Bit 7 : Si Bit of Frame 15 (SiF15)  
Bit 6 : Si Bit of Frame 13 (SiF13)  
Bit 5 : Si Bit of Frame 11 (SiF11)  
Bit 4 : Si Bit of Frame 9 (SiF9)  
Bit 3 : Si Bit of Frame 7 (SiF7)  
Bit 2 : Si Bit of Frame 5 (SiF5)  
Bit 1 : Si Bit of Frame 3 (SiF3)  
Bit 0 : Si Bit of Frame 1 (SiF1)  
Register Name:  
Register Description:  
Address (hex):  
RRA  
Received Remote Alarm  
0068, 0268, 0468, 0668  
Bit #  
7
6
5
4
3
2
1
0
Name  
RRAF1  
RRAF1  
RRAF1  
RRAF9  
RRAF7  
RRAF5  
RRAF3  
RRAF1  
5
3
1
Default  
0
0
0
0
0
0
0
0
Bit 7 : Remote Alarm Bit of Frame 15 (RRAF15)  
Bit 6 : Remote Alarm Bit of Frame 13 (RRAF13)  
Bit 5 : Remote Alarm Bit of Frame 11 (RRAF11)  
Bit 4 : Remote Alarm Bit of Frame 9 (RRAF9)  
Bit 3 : Remote Alarm Bit of Frame 7 (RRAF7)  
Bit 2 : Remote Alarm Bit of Frame 5 (RRAF5)  
Bit 1 : Remote Alarm Bit of Frame 3 (RRAF3)  
Bit 0 : Remote Alarm Bit of Frame 1 (RRAF1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSa4  
Received Sa4 Bits  
0069, 0269, 0469, 0669  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RSa4F15 RSa4F13 RSa4F11 RSa4F9 RSa4F7 RSa4F5 RSa4F3 RSa4F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa4 Bit of Frame 15 (RSa4F15)  
Bit 6 : Sa4 Bit of Frame 13 (RSa4F13)  
Bit 5 : Sa4 Bit of Frame 11 (RSa4F11)  
Bit 4 : Sa4 Bit of Frame 9 (RSa4F9)  
Bit 3 : Sa4 Bit of Frame 7 (RSa4F7)  
Bit 2 : Sa4 Bit of Frame 5 (RSa4F5)  
Bit 1 : Sa4 Bit of Frame 3 (RSa4F3)  
Bit 0 : Sa4 Bit of Frame 1 (RSa4F1)  
Register Name:  
Register Description:  
Address (hex):  
RSa5  
Received Sa5 Bits  
006A, 026A, 046A, 066A  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RSa5F15 RSa5F13 RSa5F11 RSa5F9 RSa5F7 RSa5F5 RSa5F3 RSa5F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa5 Bit of Frame 15 (RSa5F15)  
Bit 6 : Sa5 Bit of Frame 13 (RSa5F13)  
Bit 5 : Sa5 Bit of Frame 11 (RSa5F11)  
Bit 4 : Sa5 Bit of Frame 9 (RSa5F9)  
Bit 3 : Sa5 Bit of Frame 7 (RSa5F7)  
Bit 2 : Sa5 Bit of Frame 5 (RSa5F5)  
Bit 1 : Sa5 Bit of Frame 3 (RSa5F3)  
Bit 0 : Sa5 Bit of Frame 1 (RSa5F1  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSa6  
Received Sa6 Bits  
006B, 026B, 046B, 066B  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RSa6F15 RSa6F13 RSa6F11 RSa6F9 RSa6F7 RSa6F5 RSa6F3 RSa6F1  
0 0 0 0 0  
0
0
0
Bit 7 : Sa6 Bit of Frame 15 (RSa6F15)  
Bit 6 : Sa6 Bit of Frame 13 (RSa6F13)  
Bit 5 : Sa6 Bit of Frame 11 (RSa6F11)  
Bit 4 : Sa6 Bit of Frame 9 (RSa6F9)  
Bit 3 : Sa6 Bit of Frame 7 (RSa6F7)  
Bit 2 : Sa6 Bit of Frame 5 (RSa6F5)  
Bit 1 : Sa6 Bit of Frame 3 (RSa6F3)  
Bit 0 : Sa6 Bit of Frame 1 (RSa6F1)  
Register Name:  
Register Description:  
Address (hex):  
RSa7  
Received Sa7 Bits  
006C, 026C, 046C, 066C  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RSa7F15 RSa7F13 RSa7F11 RSa7F9 RSa7F7 RSa7F5 RSa7F3 RSa7F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa7 Bit of Frame 15 (RSa4F15)  
Bit 6 : Sa7 Bit of Frame 13 (RSa7F13)  
Bit 5 : Sa7 Bit of Frame 11 (RSa7F11)  
Bit 4 : Sa7 Bit of Frame 9 (RSa7F9)  
Bit 3 : Sa7 Bit of Frame 7 (RSa7F7)  
Bit 2 : Sa7 Bit of Frame 5 (RSa7F5)  
Bit 1 : Sa7 Bit of Frame 3 (RSa7F3)  
Bit 0 : Sa7 Bit of Frame 1 (RSa7F1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RSa8  
Received Sa8 Bits  
006D, 026D, 046D, 066D  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
RSa8F15 RSa8F13 RSa8F11 RSa8F9 RSa8F7 RSa8F5 RSa8F3 RSa8F1  
0
0
0
0
0
0
0
0
Bit 0 : Sa8 Bit of Frame 1 (RSa8F1)  
Bit 1 : Sa8 Bit of Frame 3 (RSa8F3)  
Bit 2 : Sa8 Bit of Frame 5 (RSa8F5)  
Bit 3 : Sa8 Bit of Frame 7 (RSa8F7)  
Bit 4 : Sa8 Bit of Frame 9 (RSa8F9)  
Bit 5 : Sa8 Bit of Frame 11 (RSa8F11)  
Bit 6 : Sa8 Bit of Frame 13 (RSa8F13)  
Bit 7 : Sa8 Bit of Frame 15 (RSa8F15)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.13 Receive Framer HDLC Controller  
Each transmit and receive framer has an HDLC controller with 64-byte FIFOs. These HDLC controllers are not the  
same as the controllers in the packet interface block. The HDLC controllers automatically generate and detect  
flags, generate and check the CRC checksum, generate and detect abort sequences, stuff and destuff zeros, and  
byte align to the data stream.  
Register Name:  
Register Description:  
Address (hex):  
RHC  
Receive HDLC Control Register  
0010, 0210, 0410, 0610  
Bit #  
Name  
Default  
7
RCRCD  
0
6
RHR  
0
5
RHMS  
0
4
RHCS4  
0
3
2
1
RHCS1  
0
0
RHCS0  
0
RHCS3 RHCS2  
0
0
Bit 0 to Bit 4 : Receive HDLC Channel Select (RHCSx) These bits determine which DS0 is mapped to the HDLC  
controller when enabled with RHMS = 0. RHCS0 to RHCS4 = all 0s selects channel 1, RHCS0 to RHCS4 = all 1s  
selects channel 32 (E1).  
Bit 5 : Receive HDLC Mapping Select (RHMS)  
0 = Receive HDLC assigned to channels  
1 = Receive HDLC assigned to FDL (T1 mode), Sa Bits (E1 mode)  
Bit 6 : Receive HDLC Reset (RHR) Will reset the receive HDLC controller and flush the receive FIFO. Must be  
cleared and set again for a subsequent reset.  
0 = Normal operation  
1 = Reset receive HDLC controller and flush the receive FIFO  
Bit 7 : Receive CRC16 Display (RCRCD)  
0 = Do not write received CRC16 code to FIFO  
1= Write received CRC16 code to FIFO after last octet of packet  
Register Name:  
Register Description:  
Address (hex):  
RHBSE  
Receive HDLC Bit Suppress Register  
0011, 0211, 0411, 0611  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 0 : Receive Channel Bit 1 Suppress:Sa8 Bit Suppress (BSE1) LSB of the channel. Set to one to stop this bit  
from being used.  
Bit 1 : Receive Channel Bit 2 Suppress/Sa7 Bit Suppress (BSE2) Set to one to stop this bit from being used  
Bit 2 : Receive Channel Bit 3 Suppress/Sa6 Bit Suppress (BSE3) Set to one to stop this bit from being used  
Bit 3 : Receive Channel Bit 4 Suppress/Sa5 Bit Suppress (BSE4) Set to one to stop this bit from being used  
Bit 4 : Receive Channel Bit 5 Suppress/Sa4 Bit Suppress (BSE5) Set to one to stop this bit from being used  
Bit 5 : Receive Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 6 : Receive Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 7 : Receive Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.13.1HDLC FIFO Control  
Control of the receive FIFO is accomplished via the Receive HDLC FIFO Control Register (RHFC). The FIFO  
Control register sets the watermarks for the receive FIFO.  
When the receive FIFO fills above the high watermark, the RHWM bit (RRTS5.1) will be set. RHWM is a real-time  
bit and will remain set as long as the receive FIFO’s write pointer is above the watermark. If enabled, this condition  
can also cause an interrupt via the INT pin.  
Register Name:  
Register Description:  
Address (hex):  
RHFC  
Receive HDLC FIFO Control Register  
0087, 0287, 0487, 0687  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
RFHWM1 RFHWM0  
0
0
Bits 7 to 2: Unused. Must be set = 0 for proper operation.  
Bits 1 & 0 : Receive FIFO High Watermark Select (RFHWM1 to RFHWM0)  
Receive FIFO Watermark  
RFHWM1 RFHWM0  
(bytes)  
0
0
1
1
0
1
0
1
4
16  
32  
48  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.13.2Receive Packet Bytes Available  
The lower 6 bits of the Receive Packet Bytes Available register indicates the number of bytes (0 through 64) that  
can be read from the receive FIFO. The value indicated by this register informs the host as to how many bytes can  
be read from the receive FIFO without going past the end of a message. This value will refer to one of four  
possibilities, the first part of a packet, the continuation of a packet, the last part of a packet, or a complete packet.  
After reading the number of bytes indicated by this register the host then checks the HDLC Status register for  
detailed message status.  
If the value in the RHPBA register refers to the beginning portion of a message or continuation of a message then  
the MSB of the RHPBA register will return a value of 1. This indicates that the host may safely read the number of  
bytes returned by the lower 6 bits of the RHPBA register but there is no need to check the information register  
since the packet has not yet terminated (successfully or otherwise).  
Register Name:  
Register Description:  
Address (hex):  
RHPBA  
Receive HDLC Packet Bytes Available Register  
00B5, 02B5, 04B5, 06B5  
Bit #  
Name  
Default  
7
MS  
0
6
RPBA6  
0
5
RPBA5  
0
4
RPBA4  
0
3
RPBA3  
0
2
RPBA2  
0
1
RPBA1  
0
0
RPBA0  
0
Bit 7 : Message Status (MS)  
0 = Bytes indicated by RPBA0 through RPBA6 are the end of a message. Host must check the HDLC  
Status register for details.  
1 = Bytes indicated by RPBA0 through RPBA6 are the beginning or continuation of a message. The host  
does not need to check the HDLC Status.  
Bits 6 to 0 : Receive FIFO Packet Bytes Available Count (RPBA6 to RPBA0) RPBA0 is the LSB.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RHF  
Receive HDLC FIFO Register  
00B6, 02B6, 04B6, 06B6  
Bit #  
Name  
Default  
7
RHD7  
0
6
RHD6  
0
5
RHD5  
0
4
RHD4  
0
3
RHD3  
0
2
RHD2  
0
1
RHD1  
0
0
RHD0  
0
Bit 7 : Receive HDLC Data Bit 7 (RHD7) MSB of a HDLC packet data byte.  
Bit 6 : Receive HDLC Data Bit 6 (RHD6)  
Bit 5 : Receive HDLC Data Bit 5 (RHD5)  
Bit 4 : Receive HDLC Data Bit 4 (RHD4)  
Bit 3 : Receive HDLC Data Bit 3 (RHD3)  
Bit 2 : Receive HDLC Data Bit 2 (RHD2)  
Bit 1 : Receive HDLC Data Bit 1 (RHD1)  
Bit 0 : Receive HDLC Data Bit 0 (RHD0) LSB of a HDLC packet data byte.  
11.6.13.3HDLC Status and Information  
RRTS5 and RLS5 provide status information for the receive HDLC controller. When a particular event has  
occurred (or is occurring), the appropriate bit in one of these registers will be set to a one. With the latched bits,  
when an event occurs and a bit is set to a one, it will remain set until the user reads that bit. The bit will be cleared  
when it is read and it will not be set again until the event has occurred again. The real-time bits report the current  
instantaneous conditions that are occurring and the history of these bits is not latched.  
Like the other latched status registers, the user will follow a read of the status bit with a write. The byte written to  
the register will inform the device which of the latched bits the user wishes to clear (the real time bits are not  
affected by writing to the status register). The user will write a byte to one of these registers, with a one in the bit  
positions he or she wishes to clear and a zero in the bit positions he or she does not wish to clear.  
The HDLC status register RLS5 has the ability to initiate a hardware interrupt via the INT output signal. Each of the  
events in this register can be either masked or unmasked from the interrupt pin via the receive HDLC Interrupt  
Mask Register (RIM5). Interrupts will force the INT signal low when the event occurs. The INT pin will be allowed to  
return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.  
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Register Name:  
Register Description:  
Address (hex):  
RRTS5  
Receive Real-Time Status 5 (HDLC)  
00B4, 02B4, 04B4, 06B4  
Bit #  
Name  
Default  
7
0
6
PS2  
0
5
PS1  
0
4
PS0  
0
3
—-  
0
2
0
1
RHWM  
0
0
RNE  
0
All bits in this register are real-time.  
Bit 7 : Unused.  
Bits 6 to 4 : Receive Packet Status (PS2 to PS0) These are real-time bits indicating the status as of the last read  
of the receive FIFO.  
PS2 PS1 PS0  
PACKET STATUS  
0
0
0
0
0
1
0
1
0
In Progress: End of message has not yet been reached.  
Packet OK: Packet ended with correct CRC codeword.  
CRC Error: A closing flag was detected, preceded by a corrupt CRC codeword.  
Abort: Packet ended because an abort signal was detected (7 or more ones in a  
row).  
Overrun: HDLC controller terminated reception of packet because receive FIFO  
is full.  
0
1
1
0
1
0
Bits 3 & 2 : Unused.  
Bit 1 : Receive FIFO Above High Watermark Condition (RHWM) Set when the receive 64-byte FIFO fills beyond  
the high watermark as defined by the Receive HDLC FIFO Control Register (RHFC). This is a real-time bit.  
Bit 0 : Receive FIFO Not Empty Condition (RNE) Set when the receive 64-byte FIFO has at least one byte  
available for a read. This is a real-time bit.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RLS5  
Receive Latched Status Register 5 (HDLC)  
0094, 0294, 0494, 0694  
Bit #  
Name  
Default  
7
0
6
0
5
ROVR  
0
4
RHOBT  
0
3
RPE  
0
2
RPS  
0
1
RHWMS  
0
0
RNES  
0
Bits 7& 6 : Unused.  
Bit 5 : Receive FIFO Overrun (ROVR) Set when the receive HDLC controller has terminated packet reception  
because the FIFO buffer is full.  
Bit 4 : Receive HDLC Opening Byte Event (RHOBT) Set when the next byte available in the receive FIFO is the  
first byte of a message.  
Bit 3 : Receive Packet End Event (RPE) Set when the HDLC controller detects either the finish of a valid  
message (i.e., CRC check complete) or when the controller has experienced a message fault such as a CRC  
checking error, or an overrun condition, or an abort has been seen. This is a latched bit and will be cleared when  
read.  
Bit 2 : Receive Packet Start Event (RPS) Set when the HDLC controller detects an opening byte. This is a  
latched bit and will be cleared when read.  
Bit 1 : Receive FIFO Above High Watermark Set Event (RHWMS) Set when the receive 64-byte FIFO crosses  
the high watermark as defined by the Receive HDLC FIFO Control Register (RHFC). Rising edge detect of RHWM.  
Bit 0 : Receive FIFO Not Empty Set Event (RNES) Set when the receive FIFO has transitioned from ‘empty’ to  
‘not-empty’ (at least one byte has been put into the FIFO). Rising edge detect of RNE.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
RIM5  
Receive Interrupt Mask 5 (HDLC)  
00A4, 02A4, 04A4, 06A4  
Bit #  
Name  
Default  
7
0
6
0
5
ROVR  
0
4
RHOBT  
0
3
RPE  
0
2
RPS  
0
1
RHWMS  
0
0
RNES  
0
Bits 7& 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Receive FIFO Overrun (ROVR)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4 : Receive HDLC Opening Byte Event (RHOBT)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3 : Receive Packet End Event (RPE)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Receive Packet Start Event (RPS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Receive FIFO Above High Watermark Set Event (RHWMS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Receive FIFO Not Empty Set Event (RNES)  
0 = interrupt masked  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.6.14 Interfacing the E1 Rx Framer to the BERT  
Register Name:  
Register Description:  
Address (hex):  
RBICR  
Receive BERT Interface Control Register  
008A, 028A, 048A, 068A  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
RBDC  
0
1
0
0
RBEN  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Receive BERT Direction Control (RBDC)  
0 = Receive Path: The BERT receives data from the network side via RPOS and RNEG.  
1 = Backplane: The BERT receives data from the system backplane via the TSER pin.  
Bit 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Receive BERT Enable (RBEN)  
0 = Receive BERT is disabled.  
1 = Receive BERT is enabled.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
RBCS1, RBCS2, RBCS3, RBCS4  
Receive BERT Channel Select Registers  
00D4 to 00D7, 02D4 to 02D7, 04D4 to 04D7, 06D4 to 06D7  
Register Name:  
Register Description:  
Address (hex):  
Setting any of the CH1 through CH32 bits in the RBCS1 through RBCS4 registers will map data from those  
channels to the on-board BERT. RBEN must be set to one for these registers to have effect. Multiple, or all  
channels may be selected simultaneously. These registers work with the receive-side framer only.  
(MSB)  
CH8  
CH16  
CH24  
CH32  
(LSB)  
CH1  
CH9  
CH17  
CH25  
CH7  
CH15  
CH23  
CH31  
CH6  
CH14  
CH22  
CH30  
CH5  
CH13  
CH21  
CH29  
CH4  
CH12  
CH20  
CH28  
CH3  
CH11  
CH19  
CH27  
CH2  
CH10  
CH18  
CH26  
RBCS1  
RBCS2  
RBCS3  
RBCS4  
Register Name:  
Register Description:  
Address (hex):  
RBBS  
Receive BERT Bit Suppress Register  
008B, 028B, 048B, 068B  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 7 : Receive Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Receive Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 5 : Receive Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 4 : Receive Channel Bit 5 Suppress (BSE5) Set to one to stop this bit from being used.  
Bit 3 : Receive Channel Bit 4 Suppress (BSE4) Set to one to stop this bit from being used.  
Bit 2 : Receive Channel Bit 3 Suppress (BSE3) Set to one to stop this bit from being used.  
Bit 1 : Receive Channel Bit 2 Suppress (BSE2) Set to one to stop this bit from being used.  
Bit 0 : Receive Channel Bit 1 Suppress (BSE1) LSB of the channel. Set to one to stop this bit from being used.  
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11.7 E1 Transmit framer  
Table 11-18 E1 Transmit Framer Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
NAME  
FUNCTION  
PORT 3 + 400h  
PORT 4 + 600h  
0100-010F  
0110  
0111  
0112  
0113  
0114  
0115  
0116  
0117  
0118  
0119  
011A  
011B  
011C – 011F  
0120  
0121  
0122  
0123  
0124  
0125  
0126  
0127  
0128  
0129  
012A  
012B  
012C  
012D  
012E  
012F  
0130  
0131  
0132  
0133  
0134  
0135  
0136  
0137  
0138  
0139  
013A  
013B  
013C  
013D  
013E  
013F  
THC1  
THBSE  
THC2  
Unused. Must be set = 0 for proper operation.  
Tx HDLC Control 1  
Tx HDLC Bit Suppress  
Unused. Must be set = 0 for proper operation.  
Tx HDLC Control 2  
Tx Sa Bit Control Register  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Tx Software Signaling Insertion Enable 1  
Tx Software Signaling Insertion Enable 2  
Tx Software Signaling Insertion Enable 3  
Tx Software Signaling Insertion Enable 4  
Unused. Must be set = 0 for proper operation.  
Tx Idle Definition 1  
Tx Idle Definition 2  
Tx Idle Definition 3  
Tx Idle Definition 4  
Tx Idle Definition 5  
Tx Idle Definition 6  
Tx Idle Definition 7  
Tx Idle Definition 8  
Tx Idle Definition 9  
Tx Idle Definition 10  
Tx Idle Definition 11  
Tx Idle Definition 12  
Tx Idle Definition 13  
Tx Idle Definition 14  
Tx Idle Definition 15  
Tx Idle Definition 16  
Tx Idle Definition 17  
Tx Idle Definition 18  
Tx Idle Definition 19  
Tx Idle Definition 20  
Tx Idle Definition 21  
Tx Idle Definition 22  
Tx Idle Definition 23  
Tx Idle Definition 24  
Tx Idle Definition 25  
TSACR  
SSIE1  
SSIE2  
SSIE3  
SSIE4  
-
TIDR1  
TIDR2  
TIDR3  
TIDR4  
TIDR5  
TIDR6  
TIDR7  
TIDR8  
TIDR9  
TIDR10  
TIDR11  
TIDR12  
TIDR13  
TIDR14  
TIDR15  
TIDR16  
TIDR17  
TIDR18  
TIDR19  
TIDR20  
TIDR21  
TIDR22  
TIDR23  
TIDR24  
TIDR25  
TIDR26  
TIDR27  
TIDR28  
TIDR29  
TIDR30  
TIDR31  
TIDR32  
Tx Idle Definition 26  
Tx Idle Definition 27  
Tx Idle Definition 28  
Tx Idle Definition 29  
Tx Idle Definition 30  
Tx Idle Definition 31  
Tx Idle Definition 32  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0140  
NAME  
FUNCTION  
TS1  
TS2  
TS3  
TS4  
TS5  
TS6  
TS7  
TS8  
TS9  
TS10  
TS11  
TS12  
TS13  
TS14  
TS15  
TS16  
TCICE1  
TCICE2  
TCICE3  
TCICE4  
Tx Signaling 1  
Tx Signaling 2  
Tx Signaling 3  
Tx Signaling 4  
Tx Signaling 5  
Tx Signaling 6  
Tx Signaling 7  
Tx Signaling 8  
Tx Signaling 9  
Tx Signaling 10  
Tx Signaling 11  
Tx Signaling 12  
Tx Signaling 13  
Tx Signaling 14  
Tx Signaling 15  
Tx Signaling 16  
0141  
0142  
0143  
0144  
0145  
0146  
0147  
0148  
0149  
014A  
014B  
014C  
014D  
014E  
014F  
0150  
Tx Channel Idle Code Enable 1  
Tx Channel Idle Code Enable 2  
Tx Channel Idle Code Enable 3  
Tx Channel Idle Code Enable 4  
Unused. Must be set = 0 for proper operation.  
Tx Align Frame  
0151  
0152  
0153  
0154-0163  
0164  
TAF  
0165  
0166  
0167  
0168  
TNAF  
TSiAF  
TSiNAF  
TRA  
Tx Non-Align Frame  
Tx Si bits for Align Frame  
Tx Si bits for Non-Align Frame  
Tx Remote Alarm  
0169  
016A  
016B  
016C  
TSa4  
TSa5  
TSa6  
TSa7  
TSa8  
TMMR  
TCR1  
TCR2  
TCR3  
TIOCR  
TGCCR  
THFC  
-
TDS0SEL  
TBICR  
TBBS  
Tx Sa4 Bits  
Tx Sa5 Bits  
Tx Sa6 Bits  
Tx Sa7 Bits  
016D  
Tx Sa8 Bits  
016E-017F  
0180  
Unused. Must be set = 0 for proper operation.  
Tx Master Mode  
Tx Control 1  
Tx Control 2  
Tx Control 3  
0181  
0182  
0183  
0184  
0185  
0186  
0187  
0188  
0189  
018A  
018B  
018C  
018D  
018E  
018F  
0190  
Tx I/O Configuration  
Tx Gapped Clock Control  
Unused. Must be set = 0 for proper operation.  
Tx HDLC FIFO Control  
Unused. Must be set = 0 for proper operation.  
Tx DS0 Monitor Select  
Tx BERT Interface Control  
Tx BERT Bit Suppress En  
Unused. Must be set = 0 for proper operation.  
Unused. Must be set = 0 for proper operation.  
Tx Synchronizer Control  
Unused. Must be set = 0 for proper operation.  
Tx Latched Status 1  
TSYNCC  
-
TLS1  
TLS2  
0191  
Tx Latched Status 2 (HDLC)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0192  
NAME  
FUNCTION  
TLS3  
TIIR  
Tx Latched Status 3 (SYNC)  
0193-019E  
019F  
Unused. Must be set = 0 for proper operation.  
Tx Interrupt Information Register  
Tx Interrupt Mask Register 1  
01A0  
TIM1  
01A1  
01A2  
01A3-01B0  
01B1  
TIM2  
TIM3  
TRTS2  
Tx Interrupt Mask Register 2 (HDLC)  
Tx Interrupt Mask Register 3 (SYNC)  
Unused. Must be set = 0 for proper operation.  
Tx Real-Time Status Register 2 (HDLC)  
Unused. Must be set = 0 for proper operation.  
Tx HDLC FIFO Buffer Available  
Tx HDLC FIFO  
01B2  
01B3  
01B4  
TFBA  
THF  
01B5-01BA  
01BB  
01BC-01C3  
01C4  
TDS0M  
Unused. Must be set = 0 for proper operation.  
Tx DS0 Monitor  
Unused. Must be set = 0 for proper operation.  
Tx Channel Mark 1  
Tx Channel Mark 2  
Tx Channel Mark 3  
TCMR1  
TCMR2  
TCMR3  
TCMR4  
THSCS1  
THSCS2  
THSCS3  
THSCS4  
TGCCS1  
TGCCS2  
TGCCS3  
TGCCS4  
PCL1  
PCL2  
PCL3  
PCL4  
TBCS1  
TBCS2  
TBCS3  
TBCS4  
01C5  
01C6  
01C7  
01C8  
01C9  
01CA  
01CB  
01CC  
01CD  
01CE  
01CF  
01D0  
01D1  
01D2  
01D3  
01D4  
Tx Channel Mark 4  
Tx Hardware Signaling Channel Select 1  
Tx Hardware Signaling Channel Select 2  
Tx Hardware Signaling Channel Select 3  
Tx Hardware Signaling Channel Select 4  
Tx Gapped Clock Channel Select 1  
Tx Gapped Clock Channel Select 2  
Tx Gapped Clock Channel Select 3  
Tx Gapped Clock Channel Select 4  
Per-Channel Loopback Enable 1  
Per-Channel Loopback Enable 2  
Per-Channel Loopback Enable 3  
Per-Channel Loopback Enable 4  
Tx BERT Channel Select 1  
01D5  
01D6  
01D7  
Tx BERT Channel Select 2  
Tx BERT Channel Select 3  
Tx BERT Channel Select 4  
Unused. Must be set = 0 for proper operation.  
01D8 – 01FF  
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11.7.1 Transmit Master Mode Register  
The Transmit Master Mode Register (TMMR) controls the initialization of the transmit side formatter. The FRM_EN  
bit may be left ‘low’ if the formatter for that particular port is not going to be used, putting the circuit in a low-power  
(sleep) state.  
Register Name:  
Register Description:  
Address (hex):  
TMMR  
Transmit Master Mode Register  
0180, 0380, 0580, 0780  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
FRM_EN  
INIT_DONE  
SFTRST  
T1/E1  
0
0
0
0
0
0
0
0
Bit 7 : Framer Enable (FRM_EN) This bit must be written with the desired value prior to setting INIT_DONE.  
0 = Framer disabled – held in low power state  
1 = Framer enabled – all features active  
Bit 6 : Initialization Done (INIT_DONE) The host (user) must set this bit once he/she has written the configuration  
registers. The host is required to write or clear all RAM based registers (addresses 100H to 17FH) prior to setting  
this bit. Once INIT_DONE is set, the internal processor will check the FRM_EN bit. If enabled, the internal  
processor continues executing based on the initial configuration.  
Bits 5 to 2 : Unused. Must be set = 0 for proper operation.  
Bit 1 : Soft Reset (SFTRST) Level sensitive processor reset. Should be taken high then low to reset and initialize  
the internal processor.  
0 = Normal Operation  
1 = Hold the internal RISC in reset. This bit only affects the transmit side processor.  
Bit 0 : Transmitter T1/E1 Mode Select (T1/E1) Sets operating mode for transmitter only! This bit must be written  
with the desired value prior to setting INIT_DONE.  
0 = T1 operation  
1 = E1 operation  
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11.7.2 Interrupt Information Registers  
The Interrupt Information Registers provide an indication of which DS26556 Status Registers are generating an  
interrupt. When an interrupt occurs, the host can read TIIR to quickly identify which of the transmit status registers  
are causing the interrupt(s). These are real-time registers in that the bits will clear once the appropriate interrupt  
has been serviced and cleared.  
Register Name:  
Register Description:  
Address (hex):  
TIIR  
Transmit Interrupt Information Register  
019F, 039F, 059F, 079F  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
TLS3  
0
1
TLS2  
0
0
TLS1  
0
11.7.3 E1 Transmit Control Registers  
Register Name:  
Register Description:  
Address (hex):  
TCR1  
Transmit Control Register 1  
0181, 0381, 0581, 0781  
Bit #  
Name  
Default  
7
TFPT  
0
6
T16S  
0
5
TG802  
0
4
TSiS  
0
3
TSA1  
0
2
THDB3  
0
1
TAIS  
0
0
TCRC4  
0
Bit 7 : Transmit Time Slot 0 Pass Through (TFPT)  
0 = FAS bits/Sa bits/Remote Alarm sourced internally from the TAF and TNAF registers  
1 = FAS bits/Sa bits/Remote Alarm sourced from TSER  
Bit 6 : Transmit Time Slot 16 Data Select (T16S)  
0 = time slot 16 determined by the SSIEx and THSCS registers  
1 = source time slot 16 from TS1 to TS16 registers  
Bit 5 : Transmit G.802 Enable (TG802)  
0 = do not force TCHMRK high during bit 1 of time slot 26  
1 = force TCHMRK high during bit 1 of time slot 26  
Bit 4 : Transmit International Bit Select (TSiS)  
0 = sample Si bits at TSER pin  
1 = source Si bits from TAF and TNAF registers (in this mode, TCR1.7 must be set to 0)  
Bit 3 : Transmit Signaling All Ones (TSA1)  
0 = normal operation  
1 = force time slot 16 in every frame to all ones  
Bit 2 : Transmit HDB3 Enable (THDB3)  
0 = HDB3 disabled  
1 = HDB3 enabled  
Bit 1 : Transmit AIS (TAIS)  
0 = transmit data normally  
1 = transmit an unframed all-ones code  
Bit 0 : Transmit CRC4 Enable (TCRC4)  
0 = CRC4 disabled  
1 = CRC4 enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCR2  
Transmit Control Register 2  
0182, 0382, 0582, 0782  
Bit #  
Name  
Default  
7
AEBE  
0
6
AAIS  
0
5
ARA  
0
4
0
3
0
2
0
1
0
0
0
Bit 7 : Automatic E-Bit Enable (AEBE)  
0 = E-bits not automatically set in the transmit direction  
1 = E-bits automatically set in the transmit direction  
Bit 6 : Automatic AIS Generation (AAIS)  
0 = disabled  
1 = enabled  
Bit 5 : Automatic Remote Alarm Generation (ARA)  
0 = disabled  
1 = enabled  
Bits 4 to 0 : Unused. Must be set = 0 for proper operation.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TCR3  
Transmit Control Register 3  
0183, 0383, 0583, 0783  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
TCSS1  
0
4
TCSS0  
0
3
-
0
2
-
0
1
IBPV  
0
0
CRC4R  
0
Bits 7 & 6 : Unused, must be set = 0 for proper operation  
Bit 5 & 4 : Transmit Clock Source Select bit 1 and 0 (TCSS1, TCSS0)  
TCSS1  
TCSS0  
Transmit Clock Source  
0
0
The TCLK pin is always the source of Transmit Clock.  
Switch to the clock present at RCLK when the signal at the TCLK pin fails to  
transition after 1 channel time.  
0
1
1
1
0
1
For Future Use  
Use the signal present at RCLK as the Transmit Clock. The TCLK pin is ignored.  
Bits 3 & 2 : Unused, must be set = 0 for proper operation  
Bit 1 : Insert BPV (IBPV) A 0-to-1 transition on this bit will cause a single BiPolar Violation (BPV) to be inserted  
into the transmit data stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next  
occurrence of three consecutive ones to insert the BPV. This bit must be cleared and set again for a subsequent  
error to be inserted.  
Bit 0 : CRC-4 Recalculate (CRC4R)  
0 = transmit CRC-4 generation and insertion operates in normal mode  
1 = transmit CRC-4 generation operates according to G.706 Intermediate Path Recalculation method.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIOCR  
Transmit I/O Configuration Register  
0184, 0384, 0584, 0784  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
0
TSM  
0
TCLKINV TSYNCINV HSSYNCINV HSCLKM HSSM TSIO  
0
0
0
0
0
0
Bit 7 : TCLK Invert (TCLKINV)  
0 = No inversion  
1 = Invert  
Bit 6 : TSYNC Invert (TSYNCINV)  
0= No inversion  
1 = Invert  
Bit 5 : HSSYNC Invert (HSSYNCINV)  
0 = No inversion  
1 = Invert  
Bit 4 : HSYSCLK Mode Select (HSCLKM)  
0 = if HSYSCLK is 1.544MHz  
1 = if HSYSCLK is 2.048/4.096/8.192/16.384MHz  
Note: This bit must be set the same as the RIOCR.HSCLKM bit  
Bit 3 : HSSYNC Mode Select (HSSM) Selects frame or multiframe mode for the HSSYNC pin.  
0 = frame mode  
1 = multiframe mode  
Bit 2 : TSYNC I/O Select (TSIO)  
0 = TSYNC is an input  
1 = TSYNC is an output  
Bit 1 : Unused, must be set = 0 for proper operation.  
Bit 0 : TSYNC Mode Select (TSM) Selects frame or multiframe mode for the TSYNC pin when TSYNC is an  
output.  
0 = frame mode  
1 = multiframe mode  
11.7.4 E1 Transmit Status and Information  
When a particular event has occurred (or is occurring), the appropriate bit in one of these registers will be set to a  
one. Status bits may operate in either a latched or real-time fashion. Some latched bits may be enabled to  
generate a hardware interrupt via the INT signal.  
Real-Time Bits  
Some status bits operate in a real-time fashion. These bits are read-only and indicate the present state of an alarm  
or a condition. Real-time bits will remain stable, and valid during the host read operation. The current value of the  
internal status signals can be read at any time from the real-time status registers without changing any the latched  
status register bits  
Latched Bits  
When an event or an alarm occurs and a latched bit is set to a one, it will remain set until cleared by the user.  
These bits typically respond on a change-of-state for an alarm, condition, or event; and operate in a read-then-  
write fashion. The user should read the value of the desired status bit, and then write a 1 to that particular bit  
location in order to clear the latched value (write a ‘0’ to locations not to be cleared). Once the bit is cleared, it will  
not be set again until the event has occurred again.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Mask Bits  
Some of the alarms and events can be either masked or unmasked from the interrupt pin via the Interrupt Mask  
Registers (TIMx). When unmasked, the INT signal will be forced low when the enabled event or condition occurs.  
The INT pin will be allowed to return high (if no other unmasked interrupts are present) when the user reads then  
clears (with a write) the alarm bit that caused the interrupt to occur. Note that the latched status bit and the INT pin  
will clear even if the alarm is still present.  
Register Name:  
Register Description:  
Address (hex):  
TLS1  
Transmit Latched Status Register 1  
0190, 0390, 0590, 0790  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
0
3
TAF  
0
2
TMF  
0
1
LOTCC  
0
0
LOTC  
0
All bits in this register are latched and can cause interrupts.  
Bits 7 to 4 : Unused  
Bit 3 : Transmit Align Frame Event (TAF) Set every 250μs at the beginning of align frames. Used to alert the  
host that the TAF and TNAF registers need to be updated.  
Bit 2 : Transmit Multiframe Event (TMF) Set every 2ms (regardless if CRC4 is enabled) on transmit multiframe  
boundaries. Used to alert the host that signaling data needs to be updated.  
Bit 1 : Loss of Transmit Clock Condition Clear (LOTCC) Set when the LOTC condition has cleared (a clock has  
been sensed at the TCLK pin).  
Bit 0 : Loss of Transmit Clock Condition (LOTC) Set when the TCLK pin has not transitioned for approximately  
3 clock periods. Will force the LOTC pin high if enabled. The host can clear this bit even if the condition is still  
present. The LOTC pin will remain high while the condition exists, even if the host has cleared the status bit. If  
enabled by TIM1.0, the INT pin transitions low when this bit is set, and transitions high when this bit is cleared (if no  
other unmasked interrupt conditions exist).  
307 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIM1  
Transmit Interrupt Mask Register 1  
01A0, 03A0, 05A0, 07A0  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
-
0
4
-
0
3
TAF  
0
2
TMF  
0
1
LOTCC  
0
0
LOTC  
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit Align Frame Event (TAF)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Transmit Multiframe Event (TMF)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Loss of Transmit Clock Clear Condition (LOTCC)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Loss of Transmit Clock Condition (LOTC)  
0 = interrupt masked  
1 = interrupt enabled  
11.7.5 Per-Channel Loopback  
The Per-Channel Loopback Registers (PCLRs) determine which channels (if any) from the backplane should be  
replaced with the data from the receive side or in other words, off of the T1 or E1 line. If this loopback is enabled,  
then transmit and receive clocks and frame syncs must be synchronized. One method to accomplish this would be  
to tie RCLK to TCLK and RFSYNC to TSYNC. There are no restrictions on which channels can be looped back or  
on how many channels can be looped back.  
Each of the bit position in the Per-Channel Loopback Registers (PCLR1/PCLR2/PCLR3/PCLR4) represent a time  
slot in the outgoing frame. When these bits are set to a one, data from the corresponding receive channel will  
replace the data on TSER for that channel.  
Register Name:  
Register Description:  
Address (hex):  
PCL1, PCL2, PCL3, PCL4  
Per-Channel Loopback Enable Registers  
01D0 to 01D3, 03D0 to 03D3, 05D0 to 05D3, 07D0h to 07D3  
Bit #  
Name  
Name  
Name  
Name  
Default  
7
6
5
4
3
2
1
0
CH8  
CH16  
CH24  
CH32  
0
CH7  
CH15  
CH23  
CH31  
0
CH6  
CH14  
CH22  
CH30  
0
CH5  
CH13  
CH21  
CH29  
0
CH4  
CH12  
CH20  
CH28  
0
CH3  
CH11  
CH19  
CH27  
0
CH2  
CH10  
CH18  
CH26  
0
CH1  
CH9  
CH17  
CH25  
0
PCL1  
PCL2  
PCL3  
PCL4  
Bits 7 to 0 / Per-Channel Loopback Enable for Channels 32 to 1 (CH32 to CH1)  
0 = Loopback disabled  
1 = Enable Loopback. Source data from the corresponding receive channel  
308 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7.6 E1 Transmit DS0 Monitoring Function  
Register Name:  
Register Description:  
Address (hex):  
TDS0SEL  
Transmit DS0 Channel Monitor Select  
0189, 0389, 0589, 0789  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
TCM4  
0
3
TCM3  
0
2
TCM2  
0
1
TCM1  
0
0
TCM0  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bits 4 to 0 : Transmit Channel Monitor Bits (TCM4 to TCM0) TCM0 is the LSB of a 5 bit channel select that  
determines which transmit channel data will appear in the TDS0M register.  
Register Name:  
Register Description:  
Address (hex):  
TDS0M  
Transmit DS0 Monitor Register  
01BB, 03BB, 05BB, 07BB  
Bit #  
Name  
Default  
7
B1  
0
6
B2  
0
5
B3  
0
4
B4  
0
3
B5  
0
2
B6  
0
1
B7  
0
0
B8  
0
Bits 7 to 0 : Transmit DS0 Channel Bits (B1 to B8) Transmit channel data that has been selected by the  
Transmit Channel Monitor Select Register. B8 is the LSB of the DS0 channel (last bit to be transmitted).  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7.7 E1 Transmit Signaling Operation  
Register Name:  
Register Description:  
Address (hex):  
TS1 TO TS16  
Transmit Signaling Registers (E1 MODE)  
0140 to 014F, 0340 to 034F, 0540 to 054F, 0740 to 074F  
Table 11-19 E1 Transmit Signaling - CAS Format  
Bit #  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Default  
7
0
6
0
5
0
4
0
3
X
2
Y
1
X
0
X
TS1  
TS2  
TS3  
TS4  
TS5  
TS6  
TS7  
TS8  
CH1-A  
CH2-A  
CH3-A  
CH4-A  
CH5-A  
CH6-A  
CH7-A  
CH8-A  
CH9-A  
CH1-B  
CH2-B  
CH3-B  
CH4-B  
CH5-B  
CH6-B  
CH7-B  
CH8-B  
CH9-B  
CH1-C  
CH2-C  
CH3-C  
CH4-C  
CH5-C  
CH6-C  
CH7-C  
CH8-C  
CH9-C  
CH1-D  
CH2-D  
CH3-D  
CH4-D  
CH5-D  
CH6-D  
CH7-D  
CH8-D  
CH9-D  
CH16-A CH16-B CH16-C CH16-D  
CH17-A CH17-B CH17-C CH17-D  
CH18-A CH18-B CH18-C CH18-D  
CH19-A CH19-B CH19-C CH19-D  
CH20-A CH20-B CH20-C CH20-D  
CH21-A CH21-B CH21-C CH21-D  
CH22-A CH22-B CH22-C CH22-D  
CH23-A CH23-B CH23-C CH23-D  
CH24-A CH24-B CH24-C CH24-D  
TS9  
TS10  
TS11  
TS12  
TS13  
TS14  
TS15  
TS16  
CH10-A CH10-B CH10-C CH10-D CH25-A CH25-B CH25-C CH25-D  
CH11-A CH11-B CH11-C CH11-D CH26-A CH26-B CH26-C CH26-D  
CH12-A CH12-B CH12-C CH12-D CH27-A CH27-B CH27-C CH27-D  
CH13-A CH13-B CH13-C CH13-D CH28-A CH28-B CH28-C CH28-D  
CH14-A CH14-B CH14-C CH14-D CH29-A CH29-B CH29-C CH29-D  
CH15-A CH15-B CH15-C CH15-D CH30-A CH30-B CH30-C CH30-D  
0
0
0
0
0
0
0
0
Table 11-20 E1 Transmit Signaling – CCS Format  
Bit #  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Name  
Default  
7
1
9
6
2
5
3
4
4
3
5
2
6
1
7
0
8
TS1  
TS2  
TS3  
TS4  
TS5  
TS6  
TS7  
TS8  
10  
18  
26  
34  
42  
50  
58  
66  
74  
82  
90  
98  
106  
114  
122  
0
11  
19  
27  
35  
43  
51  
59  
67  
75  
83  
91  
99  
107  
115  
123  
0
12  
20  
28  
36  
44  
52  
60  
68  
76  
84  
92  
100  
108  
116  
124  
0
13  
21  
29  
37  
45  
53  
61  
69  
77  
85  
93  
101  
109  
117  
125  
0
14  
22  
30  
38  
46  
54  
62  
70  
78  
86  
94  
102  
110  
118  
126  
0
15  
23  
31  
39  
47  
55  
63  
71  
79  
87  
95  
103  
111  
119  
127  
0
16  
24  
32  
40  
48  
56  
64  
72  
80  
88  
96  
104  
112  
120  
128  
0
17  
25  
33  
41  
49  
57  
65  
73  
81  
89  
97  
105  
113  
121  
0
TS9  
TS10  
TS11  
TS12  
TS13  
TS14  
TS15  
TS16  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
SSIE1  
Software Signaling Insertion Enable Register 1  
0118, 0318, 0518, 0718  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 8 to 8 (CH8 to CH1) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
Register Name:  
Register Description:  
Address (hex):  
SSIE2  
Software Signaling Insertion Enable Register 2  
0119, 0319, 0519, 0719  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 16 to 9 (CH16 TO CH9) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
Register Name:  
Register Description:  
Address (hex):  
SSIE3  
Software Signaling Insertion Enable Register 3  
011A, 031A, 051A, 071A  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 24 to 17 (CH24 TO CH17) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
311 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
SSIE4  
Software Signaling Insertion Enable Register 4  
011B, 031B, 051B, 071B  
Bit #  
Name  
Default  
7
CH32  
0
6
CH31  
0
5
CH30  
0
4
CH29  
0
3
CH28  
0
2
CH27  
0
1
CH26  
0
0
CH25  
0
Bits 7 to 0 : Software Signaling Insertion Enable for Channels 32 to 25 (CH32 TO CH25) These bits determine  
which channels are to have signaling inserted form the Transmit Signaling registers.  
0 = do not source signaling data from the TS registers for this channel  
1 = source signaling data from the TS registers for this channel  
Register Name:  
Register Description:  
Address (hex):  
THSCS1  
Transmit Hardware Signaling Channel Select Register 1  
01C8, 03C8, 05C8, 07C8,  
Bit #  
Name  
Default  
7
CH8  
0
6
CH7  
0
5
CH6  
0
4
CH5  
0
3
CH4  
0
2
CH3  
0
1
CH2  
0
0
CH1  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 8 to 1 (CH8 to CH1). This function is  
used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
Register Name:  
Register Description:  
Address (hex):  
THSCS2  
Transmit Hardware Signaling Channel Select Register 2  
01C9, 03C9, 05C9, 07C9  
Bit #  
Name  
Default  
7
CH16  
0
6
CH15  
0
5
CH14  
0
4
CH13  
0
3
CH12  
0
2
CH11  
0
1
CH10  
0
0
CH9  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 16 to 9 (CH16 to CH9). This function  
is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
312 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THSCS3  
Transmit Hardware Signaling Channel Select Register 3  
01CA, 03CA, 05CA, 07CA  
Bit #  
Name  
Default  
7
CH24  
0
6
CH23  
0
5
CH22  
0
4
CH21  
0
3
CH20  
0
2
CH19  
0
1
CH18  
0
0
CH17  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 24 to 17 (CH24 to CH17 This function  
is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine which  
channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
313 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THSCS4  
Transmit Hardware Signaling Channel Select Register 4  
01CB, 03CB, 05CB, 07CB  
Bit #  
Name  
Default  
7
CH32  
0
6
CH31  
0
5
CH30  
0
4
CH29  
0
3
CH28  
0
2
CH27  
0
1
CH26  
0
0
CH25  
0
Bits 7 to 0 / Transmit Hardware Signaling Channel Select for Channels 32 to 25 (CH32 to CH25). This  
function is used only on ports configured for high-speed multiplexed TDM bus operation. These bits determine  
which channels will have signaling data inserted from the HTSIG pin into the demultiplexed data stream from the  
HTDATA pin.  
0 = do not source signaling data from the HTSIG pin for this channel  
1 = source signaling data from the HTSIG pin for this channel  
11.7.8 E1 Transmit Per-Channel Idle Code Insertion  
Channel data can be replaced by an idle code on a per-channel basis in the transmit and receive directions.  
Thirty-two Transmit Idle Definition Registers (TIDR1-TIDR32) are provided to set the 8-bit idle code for each  
channel. The Transmit Channel Idle Code Enable registers (TCICE1-4) are used to enable idle code replacement  
on a per channel basis.  
Register Name:  
Register Description:  
Address (hex):  
TIDR1 to TIDR32  
Transmit Idle Code Definition Registers 1 to 32  
0120 to 013F, 0320 to 013F, 0520 to 053F, 0720 to 073F  
Bit #  
Name  
Default  
7
C7  
0
6
C6  
0
5
C5  
0
4
C4  
0
3
C3  
0
2
C2  
0
1
C1  
0
0
C0  
0
Bits 7 to 0 : Per-Channel Idle Code Bits (C7 to C0) C0 is the LSB of the Code (this bit is transmitted last).  
Register Name:  
Register Description:  
Address (hex):  
TCICE1, TCICE2, TCICE3, TCICE4  
Transmit Channel Idle Code Enable Registers  
0150 to 0153, 0350 to 0353, 0550 to 0553, 0750 to 0753  
The Transmit Channel Idle Code Enable Registers (TCICE1/2/3/4) are used to determine which of the 32 E1  
channels should be overwritten with the code placed in the Transmit Idle Code Definition Register.  
Bit #  
Name  
Name  
Name  
Name  
Default  
7
6
5
4
3
2
1
0
CH8  
CH16  
CH24  
CH32  
0
CH7  
CH15  
CH23  
CH31  
0
CH6  
CH14  
CH22  
CH30  
0
CH5  
CH13  
CH21  
CH29  
0
CH4  
CH12  
CH20  
CH28  
0
CH3  
CH11  
CH19  
CH27  
0
CH2  
CH10  
CH18  
CH26  
0
CH1  
CH9  
CH17  
CH25  
0
TCICE1  
TCICE2  
TCICE3  
TCICE4  
Bits 7 to 0 : Transmit Channels 32 to 1 Code Insertion Control Bits (CH32 to CH1)  
0 = do not insert data from the Idle Code Array into the transmit data stream  
1 = insert data from the Idle Code Array into the transmit data stream  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7.9 E1 Transmit Channel Mark Registers  
The Receive Channel Mark Registers (RCMR1/RCMR2/RCMR3/RCMR4) and the Transmit Channel Mark  
Registers (TCMR1/TCMR2/TCMR3/TCMR4) control the mapping of channels to the cell/packet interface and the  
RCHMRK and TCHMRK pins. The RCHMRK and TCHMRK signals are internally used to select which channels  
will be mapped to the cell/packet interface. Externally, the signal can be used to multiplex TDM data into channels  
not used by the cell/packet interface. When the appropriate bits are set to 1, the cell/packet function is mapped to  
that channel and externally the RCHMRK and TCHMRK pin is held high during the entire corresponding channel  
time. When used in T1 mode, only RCMR1 to RCMR3 and the LSB of RCMR4 are used.  
Register Name:  
Register Description:  
Address (hex):  
TCMR1, TCMR2, TCMR3, TCMR4  
Transmit Channel Mark Registers  
01C4 to 01C7, 03C4 to 03C7, 05C4 to 05C7, 07C4 to 07C7  
Bit #  
Name  
Name  
Name  
Name  
Default  
7
6
5
4
3
2
1
0
CH8  
CH16  
CH24  
CH32  
0
CH7  
CH15  
CH23  
CH31  
0
CH6  
CH14  
CH22  
CH30  
0
CH5  
CH13  
CH21  
CH29  
0
CH4  
CH12  
CH20  
CH28  
0
CH3  
CH11  
CH19  
CH27  
0
CH2  
CH10  
CH18  
CH26  
0
CH1  
CH9  
CH17  
CH25  
0
TCMR1  
TCMR2  
TCMR3  
TCMR4  
Bits 7 to 0 : Transmit Channels 32 to 1 Channel Mark Control Bits (CH32 to CH1)  
0 = force the TCHMRK pin to remain low during this channel time  
1 = force the TCHMRK pin high during this channel time  
Register Name:  
Register Description:  
Address (hex):  
TGCCR  
Transmit Gapped Clock Control Register  
0185, 0385, 0585, 0785  
Bit #  
Name  
Default  
7
6
5
-
0
4
-
0
3
-
0
2
-
0
1
-
0
0
-
0
TDATFMT TGCLKEN  
0
0
Bit 7 : Transmit Channel Data Format (TDATFMT)  
0 = 64kbps (data contained in all 8 bits)  
1 = 56kbps (data contained in 7 out of the 8 bits)  
Bit 6 : Transmit Gapped Clock Enable (TGPCKEN) ) If the TCHMRK pin is in the channel clock mode then this  
bit determines if TCHMRK outputs a pulse during the LSB of all channels or a gapped clock during selected  
channels.  
0 = pulse during LSB of all  
1 = gapped clock during selected channels  
Bits 5 to 0 : Unused. Must be set = 0 for proper operation.  
11.7.10 Fractional E1 Support (Gapped Clock Mode)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TGCCS1, TGCCS2, TGCCS3, TGCCS4  
Transmit Gapped Clock Channel Select Registers  
01CC to 01CF, 03CC to 03CF, 05CC to 05CF, 07CC to 07CF  
Bit #  
7
6
5
4
3
2
1
0
Name  
Name  
Name  
Name  
Default  
CH8  
CH16  
CH24  
CH32  
0
CH7  
CH15  
CH23  
CH31  
0
CH6  
CH14  
CH22  
CH30  
0
CH5  
CH13  
CH21  
CH29  
0
CH4  
CH12  
CH20  
CH28  
0
CH3  
CH11  
CH19  
CH27  
0
CH2  
CH10  
CH18  
CH26  
0
CH1  
CH9  
CH17  
CH25  
0
TGCCS1  
TGCCS2  
TGCCS3  
TGCCS4  
Bits 7 to 0 : Transmit Channels 32 to 1 Gapped Clock Channel Select Bits (CH32 to CH1)  
0 = no clock is present on TCHMRK during this channel time  
1 = output a clock on TCHMRK during this channel time. The clock will be synchronous with TCLK.  
11.7.11 Additional (Sa) and International (Si) Bit Operation (E1 Mode)  
Register Name:  
Register Description:  
Address (hex):  
TAF  
Transmit Align Frame Register  
0164, 0364, 0564, 0764  
Bit #  
Name  
Default  
7
Si  
0
6
0
0
5
0
0
4
1
1
3
1
1
2
0
0
1
1
1
0
1
1
Bit 7 : International Bit (Si)  
Bit 6 : Frame Alignment Signal Bit (0)  
Bit 5 : Frame Alignment Signal Bit (0)  
Bit 4 : Frame Alignment Signal Bit (1)  
Bit 3 : Frame Alignment Signal Bit (1)  
Bit 2 : Frame Alignment Signal Bit (0)  
Bit 1 : Frame Alignment Signal Bit (1)  
Bit 0 : Frame Alignment Signal Bit (1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TNAF  
Transmit Non-Align Frame Register  
0165, 0365, 0565, 0765  
Bit #  
Name  
Default  
7
Si  
0
6
1
1
5
A
0
4
Sa4  
0
3
Sa5  
0
2
Sa6  
0
1
Sa7  
0
0
Sa8  
0
Bit 7 : International Bit (Si)  
Bit 6 : Frame Non-Alignment Signal Bit (1)  
Bit 5 : Remote Alarm [used to transmit the alarm (A)]  
Bit 4 : Additional Bit 4 (Sa4)  
Bit 3 : Additional Bit 5 (Sa5)  
Bit 2 : Additional Bit 6 (Sa6)  
Bit 1 : Additional Bit 7 (Sa7)  
Bit 0 : Additional Bit 8 (Sa8)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSiAF  
Transmit Si Bits of the Align Frame  
0166, 0366, 0566 ,0766  
Bit #  
Name  
Default  
7
TSiF14  
0
6
TSiF12  
0
5
TSiF10  
0
4
TSiF8  
0
3
TSiF6  
0
2
TSiF4  
0
1
TSiF2  
0
0
TSiF0  
0
Bit 7 : Si Bit of Frame 14 (TSiF14)  
Bit 6 : Si Bit of Frame 12 (TSiF12)  
Bit 5 : Si Bit of Frame 10 (TSiF10)  
Bit 4 : Si Bit of Frame 8 (TSiF8)  
Bit 3 : Si Bit of Frame 6 (TSiF6)  
Bit 2 : Si Bit of Frame 4 (TSiF4)  
Bit 1 : Si Bit of Frame 2 (TSiF2)  
Bit 0 : Si Bit of Frame 0 (TSiF0)  
Register Name:  
Register Description:  
Address (hex):  
TSiNAF  
Transmit Si Bits of the Non-Align Frame  
0167, 0367, 0567, 0767  
Bit #  
Name  
Default  
7
TSiF15  
0
6
TSiF13  
0
5
TSiF11  
0
4
TSiF9  
0
3
TSiF7  
0
2
TSiF5  
0
1
TSiF3  
0
0
TSiF1  
0
Bit 7 : Si Bit of Frame 15 (TSiF15)  
Bit 6 : Si Bit of Frame 13 (TSiF13)  
Bit 5 : Si Bit of Frame 11 (TSiF11)  
Bit 4 : Si Bit of Frame 9 (TSiF9)  
Bit 3 : Si Bit of Frame 7 (TSiF7)  
Bit 2 : Si Bit of Frame 5 (TSiF5)  
Bit 1 : Si Bit of Frame 3 (TSiF3)  
Bit 0 : Si Bit of Frame 1 (TSiF1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TRA  
Transmit Remote Alarm  
0168, 0368, 0568, 0768  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
TRAF3  
0
0
TRAF1  
0
TRAF15 TRAF13 TRAF11 TRAF9  
TRAF7 TRAF5  
0
0
0
0
0
0
Bit 7 : Remote Alarm Bit of Frame 15 (TRAF15)  
Bit 6 : Remote Alarm Bit of Frame 13 (TRAF13)  
Bit 5 : Remote Alarm Bit of Frame 11 (TRAF11)  
Bit 4 : Remote Alarm Bit of Frame 9 (TRAF9)  
Bit 3 : Remote Alarm Bit of Frame 7 (TRAF7)  
Bit 2 : Remote Alarm Bit of Frame 5 (TRAF5)  
Bit 1 : Remote Alarm Bit of Frame 3 (TRAF3)  
Bit 0 : Remote Alarm Bit of Frame 1 (TRAF1)  
Register Name:  
Register Description:  
Address (hex):  
TSa4  
Transmit Sa4 Bits  
0169, 0369, 0569 ,0769  
Bit #  
Name  
Default  
7
6
5
4
3
2
1
0
TSa4F15 TSa4F13 TSa4F11  
TSa4F9  
TSa4F7  
TSa4F5  
TSa4F3  
TSa4F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa4 Bit of Frame 15 (TSa4F15)  
Bit 6 : Sa4 Bit of Frame 13 (TSa4F13)  
Bit 5 : Sa4 Bit of Frame 11 (TSa4F11)  
Bit 4 : Sa4 Bit of Frame 9 (TSa4F9)  
Bit 3 : Sa4 Bit of Frame 7 (TSa4F7)  
Bit 2 : Sa4 Bit of Frame 5 (TSa4F5)  
Bit 1 : Sa4 Bit of Frame 3 (TSa4F3)  
Bit 0 : Sa4 Bit of Frame 1 (TSa4F1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSa5  
Transmitted Sa5 Bits  
016A, 036A, 056A ,076A  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
TSa5F15 TSa5F13 TSa5F11 TSa5F9 TSa5F7 TSa5F5 TSa5F3 TSa5F1  
0 0 0 0 0  
0
0
0
Bit 7 : Sa5 Bit of Frame 15 (TSa5F15)  
Bit 6 : Sa5 Bit of Frame 13 (TSa5F13)  
Bit 5 : Sa5 Bit of Frame 11 (TSa5F11)  
Bit 4 : Sa5 Bit of Frame 9 (TSa5F9)  
Bit 3 : Sa5 Bit of Frame 7 (TSa5F7)  
Bit 2 : Sa5 Bit of Frame 5 (TSa5F5)  
Bit 1 : Sa5 Bit of Frame 3 (TSa5F3)  
Bit 0 : Sa5 Bit of Frame 1 (TSa5F1)  
Register Name:  
Register Description:  
Address (hex):  
TSa6  
Transmit Sa6 Bits  
016B, 036B, 056B, 076B  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
TSa6F15 TSa6F13 TSa6F11 TSa6F9 TSa6F7 TSa6F5 TSa6F3 TSa6F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa6 Bit of Frame 15 (TSa6F15)  
Bit 6 : Sa6 Bit of Frame 13 (TSa6F13)  
Bit 5 : Sa6 Bit of Frame 11 (TSa6F11)  
Bit 4 : Sa6 Bit of Frame 9 (TSa6F9)  
Bit 3 : Sa6 Bit of Frame 7 (TSa6F7)  
Bit 2 : Sa6 Bit of Frame 5 (TSa6F5)  
Bit 1 : Sa6 Bit of Frame 3 (TSa6F3)  
Bit 0 : Sa6 Bit of Frame 1 (TSa6F1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSa7  
Transmit Sa7 Bits  
016C, 036C, 056C, 076C  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
TSa7F15 TSa7F13 TSa7F11 TSa7F9 TSa7F7 TSa7F5 TSa7F3 TSa7F1  
0
0
0
0
0
0
0
0
Bit 7 : Sa7 Bit of Frame 15 (TSa4F15)  
Bit 6 : Sa7 Bit of Frame 13 (TSa7F13)  
Bit 5 : Sa7 Bit of Frame 11 (TSa7F11)  
Bit 4 : Sa7 Bit of Frame 9 (TSa7F9)  
Bit 3 : Sa7 Bit of Frame 7 (TSa7F7)  
Bit 2 : Sa7 Bit of Frame 5 (TSa7F5)  
Bit 1 : Sa7 Bit of Frame 3 (TSa7F3)  
Bit 0 : Sa7 Bit of Frame 1 (TSa7F1)  
Register Name:  
Register Description:  
Address (hex):  
TSa8  
Transmit Sa8 Bits  
016D, 036D, 056D ,076D  
Bit #  
7
6
5
4
3
2
1
0
Name  
TSa8F1  
TSa8F1  
TSa8F1  
TSa8F  
TSa8F  
TSa8F  
TSa8F  
TSa8F  
5
3
1
9
7
5
3
1
Defaul  
t
0
0
0
0
0
0
0
0
Bit 7 : Sa8 Bit of Frame 15 (TSa8F15)  
Bit 6 : Sa8 Bit of Frame 13 (TSa8F13)  
Bit 5 : Sa8 Bit of Frame 11 (TSa8F11)  
Bit 4 : Sa8 Bit of Frame 9 (TSa8F9)  
Bit 3 : Sa8 Bit of Frame 7 (TSa8F7)  
Bit 2 : Sa8 Bit of Frame 5 (TSa8F5)  
Bit 1 : Sa8 Bit of Frame 3 (TSa8F3)  
Bit 0 : Sa8 Bit of Frame 1 (TSa8F1)  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TSACR  
Transmit Sa Bit Control Register  
0114, 0314, 0514, 0714  
Bit #  
Name  
Default  
7
SiAF  
0
6
SiNAF  
0
5
RA  
0
4
Sa4  
0
3
Sa5  
0
2
Sa6  
0
1
Sa7  
0
0
Sa8  
0
Bit 7 : International Bit in Align Frame Insertion Control Bit (SiAF)  
0 = do not insert data from the TSiAF register into the transmit data stream  
1 = insert data from the TSiAF register into the transmit data stream  
Bit 6 : International Bit in Non-Align Frame Insertion Control Bit (SiNAF)  
0 = do not insert data from the TSiNAF register into the transmit data stream  
1 = insert data from the TSiNAF register into the transmit data stream  
Bit 5 : Remote Alarm Insertion Control Bit (RA)  
0 = do not insert data from the TRA register into the transmit data stream  
1 = insert data from the TRA register into the transmit data stream  
Bit 4 : Additional Bit 4 Insertion Control Bit (Sa4)  
0 = do not insert data from the TSa4 register into the transmit data stream  
1 = insert data from the TSa4 register into the transmit data stream  
Bit 3 : Additional Bit 5 Insertion Control Bit (Sa5)  
0 = do not insert data from the TSa5 register into the transmit data stream  
1 = insert data from the TSa5 register into the transmit data stream  
Bit 2 : Additional Bit 6 Insertion Control Bit (Sa6)  
0 = do not insert data from the TSa6 register into the transmit data stream  
1 = insert data from the TSa6 register into the transmit data stream  
Bit 1 : Additional Bit 7 Insertion Control Bit (Sa7)  
0 = do not insert data from the TSa7 register into the transmit data stream  
1 = insert data from the TSa7 register into the transmit data stream  
Bit 0 : Additional Bit 8 Insertion Control Bit (Sa8)  
0 = do not insert data from the TSa8 register into the transmit data stream  
1 = insert data from the TSa8 register into the transmit data stream  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7.12 E1 Transmit HDLC Controller  
Register Name:  
Register Description:  
Address (hex):  
THC1  
Transmit HDLC Control Register 1  
0110, 0310, 0510, 0710  
Bit #  
Name  
Default  
7
NOFS  
0
6
TEOML  
0
5
THR  
0
4
THMS  
0
3
TFS  
0
2
TEOM  
0
1
TZSD  
0
0
TCRCD  
0
Bit 7 : Number Of Flags Select (NOFS)  
0 = send one flag between consecutive messages  
1 = send two flags between consecutive messages  
Bit 6 : Transmit End of Message and Loop (TEOML) To loop on a message, should be set to a one just before  
the last data byte of an HDLC packet is written into the transmit FIFO. The message will repeat until the user clears  
this bit or a new message is written to the transmit FIFO. If the host clears the bit, the looping message will  
complete then flags will be transmitted until new message is written to the FIFO. If the host terminates the loop by  
writing a new message to the FIFO the loop will terminate, one or two flags will be transmitted and the new  
message will start. If not disabled via TCRCD, the transmitter will automatically append a 2-byte CRC code to the  
end of all messages.  
Bit 5 : Transmit HDLC Reset (THR) Will reset the transmit HDLC controller and flush the transmit FIFO. An abort  
followed by 7Eh or FFh flags/idle will be transmitted until a new packet is initiated by writing new data into the  
FIFO. Must be cleared and set again for a subsequent reset.  
0 = Normal operation  
1 = Reset transmit HDLC controller and flush the transmit FIFO  
Bit 4 : Transmit HDLC Mapping Select (THMS)  
0 = Transmit HDLC assigned to channels  
1 = Transmit HDLC assigned to FDL(T1 mode), Sa Bits(E1 mode)  
Bit 3 : Transmit Flag/Idle Select (TFS) This bit selects the inter-message fill character after the closing and  
before the opening flags (7Eh).  
0 = 7Eh  
1 = FFh  
Bit 2 : Transmit End of Message (TEOM) Should be set to a one just before the last data byte of an HDLC packet  
is written into the transmit FIFO at THF. If not disabled via TCRCD, the transmitter will automatically append a 2-  
byte CRC code to the end of the message.  
Bit 1 : Transmit Zero Stuffer Defeat (TZSD) The Zero Stuffer function automatically inserts a zero in the  
message field (between the flags) after 5 consecutive ones to prevent the emulation of a flag or abort sequence by  
the data pattern. The receiver automatically removes (destuffs) any zero after 5 ones in the message field.  
0 = enable the zero stuffer (normal operation)  
1 = disable the zero stuffer  
Bit 0 : Transmit CRC Defeat (TCRCD) A 2-byte CRC code is automatically appended to the outbound message.  
This bit can be used to disable the CRC function.  
0 = enable CRC generation (normal operation)  
1 = disable CRC generation  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THC2  
Transmit HDLC Control Register 2  
0113, 0313, 0513, 0713  
Bit #  
Name  
Default  
7
TABT  
0
6
0
5
THCEN  
0
4
THCS4  
0
3
THCS3  
0
2
THCS2  
0
1
THCS1  
0
0
THCS0  
0
Bit 7 : Transmit Abort (TABT) A 0-to-1 transition will cause the FIFO contents to be dumped and one FEh abort  
to be sent followed by 7Eh or FFh flags/idle until a new packet is initiated by writing new data into the FIFO. Must  
be cleared and set again for a subsequent abort to be sent.  
Bit 6 : Unused. Must be set = 0 for proper operation.  
Bit 5 : Transmit HDLC Controller Enable (THCEN)  
0 = Transmit HDLC Controller is not enabled  
1 = Transmit HDLC Controller is enabled  
Bits 4 to 0 : Transmit HDLC Channel Select (THCS4 to 0) Determines which DSO channel will have the carry  
the HDLC message if enabled.  
Register Name:  
Register Description:  
Address (hex):  
THBSE  
Transmit HDLC Bit Suppress  
0111, 0311, 0511, 0711  
Bit #  
Name  
Default  
7
TBSE8  
0
6
TBSE7  
0
5
TBSE6  
0
4
TBSE5  
0
3
TBSE4  
0
2
TBSE3  
0
1
TBSE2  
0
0
TBSE1  
0
Bit 7 : Transmit Bit 8 Suppress (TBSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Transmit Bit 7 Suppress (TBSE7) Set to one to stop this bit from being used.  
Bit 5 : Transmit Bit 6 Suppress (TBSE6) Set to one to stop this bit from being used.  
Bit 4 : Transmit Bit 5 Suppress/Sa4 Bit Suppress (TBSE5) Set to one to stop this bit from being used  
Bit 3 : Transmit Bit 4 Suppress/Sa5 Bit Suppress (TBSE4) Set to one to stop this bit from being used  
Bit 2 : Transmit Bit 3 Suppress/Sa6 Bit Suppress (TBSE3) Set to one to stop this bit from being used  
Bit 1 : Transmit Bit 2 Suppress/Sa7 Bit Suppress (TBSE2) Set to one to stop this bit from being used  
Bit 0 : Transmit Bit 1 Suppress/Sa8 Bit Suppress (TBSE1) LSB of the channel. Set to one to stop this bit from  
being used.  
11.7.12.1Transmit HDLC FIFO Control  
Control of the transmit FIFO is accomplished via the Transmit HDLC FIFO Control (THFC). The FIFO Control  
register sets the watermarks for the receive FIFO.  
When the transmit FIFO empties below the low watermark, the TLWM bit in the appropriate HDLC status register  
will be set. TLWM is a real-time bit and will remain set as long as the transmit FIFO’s write pointer is below the  
watermark. If enabled, this condition can also cause an interrupt via the INT pin.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THFC  
Transmit HDLC FIFO Control Register  
0187, 0387, 0587, 0787  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
TFLWM1 TFLWM0  
0
0
Bits 7 to 2 : Unused. Must be set = 0 for proper operation.  
Bits 1 & 0 : Transmit HDLC FIFO Low-Watermark Select (TFLWM1 to TFLWM0)  
TFLWM1 TFLWM0 Transmit FIFO Watermark  
0
0
1
1
0
1
0
1
4 bytes  
16 bytes  
32 bytes  
48 bytes  
11.7.12.2HDLC Status and Information  
TLS2 provides status information for the transmit HDLC controller. When a particular event has occurred (or is  
occurring), the appropriate bit in one of these registers will be set to a one. Some of the bits in these registers are  
latched and some are real-time bits that are not latched. This section contains register descriptions that list which  
bits are latched and which are real time. With the latched bits, when an event occurs and a bit is set to a one, it will  
remain set until the user reads that bit. The bit will be cleared when it is read and it will not be set again until the  
event has occurred again. The real-time bits report the current instantaneous conditions that are occurring and the  
history of these bits is not latched.  
Like the other latched status registers, the user will follow a read of the status bit with a write. The byte written to  
the register will inform the device which of the latched bits the user wishes to clear (the real time bits are not  
affected by writing to the status register). The user will write a byte to one of these registers, with a one in the bit  
positions he or she wishes to clear and a zero in the bit positions he or she does not wish to clear.  
The HDLC status register, TLS2has the ability to initiate a hardware interrupt via the INT output signal. Each of the  
events in this register can be either masked or unmasked from the interrupt pin via the receive HDLC Interrupt  
Mask Register (TIM2). Interrupts will force the INT signal low when the event occurs. The INT pin will be allowed to  
return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TRTS2  
Transmit Real-Time Status Register 2 (HDLC)  
01B1, 03B1, 05B1, 07B1  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
TEMPTY  
0
2
TFULL  
0
1
TLWM  
0
0
TNF  
0
All bits in this register are real time.  
Bits 7 to 4 : Unused.  
Bit 3 : Transmit FIFO Empty (TEMPTY) A real-time bit that is set high when the FIFO is empty.  
Bit 2 : Transmit FIFO Full (TFULL) A real-time bit that is set high when the FIFO is full.  
Bit 1 : Transmit FIFO Below Low-Watermark Condition (TLWM) Set when the transmit 64-byte FIFO empties  
below the low watermark as defined by the Transmit Low-Watermark bits (TLWM).  
Bit 0 : Transmit FIFO Not Full Condition (TNF) Set when the transmit 64-byte FIFO has at least one byte  
available.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TLS2  
Transmit Latched Status Register 2 (HDLC)  
0191, 0391, 0591, 0791  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
TUDR  
0
2
TMEND  
0
1
TLWMS  
0
0
TNFS  
0
All bits in this register are latched and can create interrupts.  
Bits 7 to 4 : Unused.  
Bit 3 : Transmit FIFO Underrun Event (TUDR) Set when the transmit FIFO empties out without having seen the  
TMEND bit set. An abort is automatically sent.  
Bit 2 : Transmit Message End Event (TMEND) Set when the transmit HDLC controller has finished sending a  
message.  
Bit 1 : Transmit FIFO Below Low-Watermark Set Condition (TLWMS) Set when the transmit 64-byte FIFO  
empties beyond the low watermark as defined by the Transmit Low-Watermark bits (TLWM) (rising edge detect of  
TLWM).  
Bit 0 : Transmit FIFO Not Full Set Condition (TNFS) Set when the transmit 64-byte FIFO has at least one empty  
byte available for write. Rising edge detect of TNF. Indicates change of state from full to not full.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TIM2  
Transmit Interrupt Mask Register 2  
01A1, 03A1, 05A1, 07A1  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
2
1
TLWMS  
0
0
TNFS  
0
TUDR TMEND  
0
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : Transmit FIFO Underrun Event (TUDR)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2 : Transmit Message End Event (TMEND)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1 : Transmit FIFO Below Low Watermark Set Condition (TLWMS)  
0 = interrupt masked  
1 = interrupt enabled  
Bit 0 : Transmit FIFO Not Full Set Condition (TNFS)  
0 = interrupt masked  
1 = interrupt enabled  
11.7.12.3FIFO Information  
The Transmit FIFO Buffer Available register indicates the number of bytes that can be written into the transmit  
FIFO. The count form this register informs the host as to how many bytes can be written into the transmit FIFO  
without overflowing the buffer. This is a real-time register. The count shall remain valid and stable during the read  
cycle.  
Register Name:  
Register Description:  
Address (hex):  
TFBA  
Transmit HDLC FIFO Buffer Available  
01B3, 03B3, 05B3, 07B3  
Bit #  
Name  
Default  
7
0
6
TFBA6  
0
5
TFBA5  
0
4
TFBA4  
0
3
2
1
TFBA1  
0
0
TFBA0  
0
TFBA3 TFBA2  
0
0
Bit 7 : Unused.  
Bits 6 to 0 : Transmit FIFO Bytes Available (TFBA6 to TFBA0) TFBA0 is the LSB.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
THF  
Transmit HDLC FIFO  
01B4, 03B4, 05B4, 07B4  
Bit #  
Name  
Default  
7
THD7  
0
6
THD6  
0
5
THD5  
0
4
THD4  
0
3
THD3  
0
2
THD2  
0
1
THD1  
0
0
THD0  
0
Bit 7 : Transmit HDLC Data Bit 7 (THD7) MSB of a HDLC packet data byte.  
Bit 6 : Transmit HDLC Data Bit 6 (THD6)  
Bit 5 : Transmit HDLC Data Bit 5 (THD5)  
Bit 4 : Transmit HDLC Data Bit 4 (THD4)  
Bit 3 : Transmit HDLC Data Bit 3 (THD3)  
Bit 2 : Transmit HDLC Data Bit 2 (THD2)  
Bit 1 : Transmit HDLC Data Bit 1 (THD1)  
Bit 0 : Transmit HDLC Data Bit 0 (THD0) LSB of a HDLC packet data byte.  
11.7.13 Interfacing the E1 Transmitter to the BERT  
Register Name:  
Register Description:  
Address (hex):  
TBICR  
Transmit BERT Interface Control Register  
018A, 038A, 058A, 078A  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
TBDC  
0
1
0
0
TBEN  
0
Bits 7 to 3 : Unused. Must be set = 0 for proper operation.  
Bit 2 : Transmit BERT Direction Control (TBDC)  
0 = Transmit Path: The BERT transmits toward the network.  
1 = Backplane: The BERT transmits toward the system backplane.  
Bit 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Transmit BERT Enable (TBEN)  
0 = Transmit BERT is disabled.  
1 = Transmit BERT is enabled.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TBCS1, TBCS2, TBCS3, TBCS4  
Transmit BERT Channel Select Registers  
01D4 to 01D7, 03D4 to 03D7, 05D4 to 05D7, 07D4 to 07D7  
Setting any of the CH1 through CH32 bits in the TBCS1 through TBCS4 registers will map data into those  
channels from the on-board BERT. TBEN must be set to one for these registers to have effect. Multiple, or all  
channels may be selected simultaneously. These registers work with the transmit-side framer only.  
Bit #  
7
6
5
4
3
2
1
0
Name  
Name  
Name  
Name  
Default  
CH8  
CH16  
CH24  
CH32  
0
CH7  
CH15  
CH23  
CH31  
0
CH6  
CH14  
CH22  
CH30  
0
CH5  
CH13  
CH21  
CH29  
0
CH4  
CH12  
CH20  
CH28  
0
CH3  
CH11  
CH19  
CH27  
0
CH2  
CH10  
CH18  
CH26  
0
CH1  
CH9  
CH17  
CH25  
0
TBCS1  
TBCS2  
TBCS3  
TBCS4  
Register Name:  
Register Description:  
Address (hex):  
TBBS  
Transmit BERT Bit Suppress Register  
018B, 0038B, 058B, 078B  
Bit #  
Name  
Default  
7
BSE8  
0
6
BSE7  
0
5
BSE6  
0
4
BSE5  
0
3
BSE4  
0
2
BSE3  
0
1
BSE2  
0
0
BSE1  
0
Bit 7 : Transmit Channel Bit 8 Suppress (BSE8) MSB of the channel. Set to one to stop this bit from being used.  
Bit 6 : Transmit Channel Bit 7 Suppress (BSE7) Set to one to stop this bit from being used.  
Bit 5 : Transmit Channel Bit 6 Suppress (BSE6) Set to one to stop this bit from being used.  
Bit 4 : Transmit Channel Bit 5 Suppress (BSE5) Set to one to stop this bit from being used.  
Bit 3 : Transmit Channel Bit 4 Suppress (BSE4) Set to one to stop this bit from being used.  
Bit 2 : Transmit Channel Bit 3 Suppress (BSE3) Set to one to stop this bit from being used.  
Bit 1 : Transmit Channel Bit 2 Suppress (BSE2) Set to one to stop this bit from being used.  
Bit 0 : Transmit Channel Bit 1 Suppress (BSE1) LSB of the channel. Set to one to stop this bit from being used.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
11.7.14 E1 Transmit Synchronizer  
Register Name:  
Register Description:  
Address (hex):  
TSYNCC  
Transmit Synchronizer Control Register  
018E, 038E, 058E, 078E  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
CRC4  
0
2
TSEN  
0
1
0
SYNCE RESYNC  
0
0
Bits 7 to 4 : Unused. Must be set = 0 for proper operation.  
Bit 3 : CRC4 Enable (RCRC4)  
0 = CRC4 disabled  
1 = CRC4 enabled  
Bit 2 : Transmit Synchronizer Enable (TSEN)  
0 = transmit synchronizer disabled  
1 = transmit synchronizer enabled  
Bit 1 : Sync Enable (SYNCE)  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 0 : Resynchronize (RESYNC) When toggled from low to high, a resynchronization of the transmit-side framer  
is initiated. Must be cleared and set again for a subsequent resync.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
TLS3  
Transmit Latched Status Register 3 (Synchronizer)  
0192, 0392, 0592, 0792  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
LOF  
0
0
LOFD  
0
Bits 7 to 2 : Unused.  
Bit 1 : Loss of Frame (LOF) A real-time bit that indicates that the transmit synchronizer is searching for the sync  
pattern in the incoming data stream.  
Bit 0 : Loss-of-Frame Synchronization Detect (LOFD) This latched bit is set when the transmit synchronizer is  
searching for the sync pattern in the incoming data stream.  
Register Name:  
Register Description:  
Address (hex):  
TIM3  
Transmit Interrupt Mask Register 3 (Synchronizer)  
01A2, 03A2, 05A2, 07A2  
Bit #  
Name  
Default  
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
LOFD  
0
Bits 7 to 1 : Unused. Must be set = 0 for proper operation.  
Bit 0 : Loss-of-Frame Synchronization Detect (LOFD)  
0 = Interrupt masked  
1 = Interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
12 LINE INTERFACE UNIT (LIU)  
Table 12-1 LIU Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
0800  
NAME  
DESCRIPTION  
LCCR1  
LTCR  
LCCR2  
LRSR  
LSIMR  
LLSR  
LRSL  
LRCR  
-
LIU Common Control Register 1  
0801  
0802  
0803  
0804  
0805  
0806  
0807  
LIU Transmit Control Register  
LIU Common Control Register 2  
LIU Real Status Register  
LIU Status Interrupt Mask Register  
LIU Latched Status Register  
LIU Receive Signal Level  
LIU Receive Control Register  
Unused. Must be set = 0 for proper operation.  
0808-080F  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
12.1 LIU Registers  
Register Name:  
Register Description:  
Address (hex):  
LCCR1  
LIU Common Control Register 1  
0800, 0A00, 0C00, 0E00  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
JADS  
0
3
JAPS1  
0
2
JAPS0  
0
1
LMODE  
0
0
LSC  
0
Bits 7 to 5 : Unused. Must be set = 0 for proper operation.  
Bit 4 : Jitter Attenuator Depth Select (JADS)  
0 = JA FIFO depth set to 128 bits.  
1 = JA FIFO depth set to 32 bits.  
Bits 3 & 2 : Jitter Attenuator Position Select 1 and 0 (JAPS1, JAPS0) Used to select the position of the jitter  
attenuator.  
JAPS1  
JAPS0  
Function  
JA in the receive path  
JA in the transmit path  
JA is not used  
0
0
1
1
0
1
0
1
JA is not used  
Bit 1 : LIU Mode Selection (LMODE)  
0 = E1 LIU functions and pulse shapes are selected.  
1 = T1/J1 LIU functions and pulse shapes are selected.  
Bit 0 : LOS Criteria Selection (LCS) This bit is used for LOS Selection Criteria. In E1 Mode, if set this bit uses  
ETSI (300233) mode selections. If reset, this bit uses G.775 criteria. In T1/J1 Mode, T1.231 criteria are selected.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
LTCR  
LIU Transmit Control Register  
0801, 0A01, 0C01, 0E01  
Bit #  
Name  
Default  
7
-
0
6
ITTIOFF  
0
5
4
3
-
0
2
TPSS2  
0
1
TPSS1  
0
0
TPSS0  
0
TIMPL1 TIMPL0  
0
0
Bit 7 : Unused. Must be set = 0 for proper operation.  
Bit 6 : Internal Transmit Terminating Impedance Off (ITTIOFF) If this bit is set, the transmit load impedance is  
turned off. Note that the user cable impedance has to be specified by TIMPL bits. The transmitter performance will  
not be optimum if the transmitter cable impedance (TIMPL2 to 0 bits) is not specified.  
Bits 5 & 4 : Transmit Load Impedance 1 and 0 (TIMPL1, TIMPL0) Used to select the transmit load source  
impedance. These have to be set according to the cable impedance. Even if the Internal Load Impedance is  
turned off (via ITTIOFF), the external cable impedance must be specified for optimum operation by TIMPL1 and  
TIMPL0. 110Ω with T1 selection is the J1 Mode.  
Table 12-2 Internal Transmit Termination Select  
TRANSMIT  
TERMINATION  
TIMPL1  
TIMPLO  
(Ω)  
75  
100  
110  
120  
0
0
1
1
0
1
0
1
Bit 3 : Unused. Must be set = 0 for proper operation.  
Bits 2 to 0 : Transmit Pulse Shape Selection 2, 1 and 0 (TPSS2, TPSS1, TPSS0) Used to select the transmit  
pulse shape. The pulse shape has voltage level and load impedance associated with it once the T1/J1/ E1  
selection is made by settings in the LCCR register.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Table 12-3 E1 Transmit Pulse Shape Selection  
TPSS2 TPSS1 TPSS0  
APPLICATION  
75Ω Coaxial  
0
0
0
0
0
1
120Ω Twisted pair  
Table 12-4 T1/J1 Transmit Pulse Shape Selection  
TPSS2 TPSS1 TPSS0  
APPLICATION  
Long Haul (0dB)  
0-133 ft DSX  
0
0
0
0
0
1
1
1
1
0
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
133-266 ft DSX  
266-399 ft DSX  
399-533 ft DSX  
533-655 ft DSX  
-7.5 dB CSU1  
-15 dB CSU1  
-22.5 dB CSU1  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
Register Description:  
Address (hex):  
LCCR2  
LIU Common Control Register 2  
0802, 0A02, 0C02, 0E02  
Bit #  
Name  
Default  
7
TAIS  
0
6
ATAIS  
0
5
LLB  
0
4
ALB  
0
3
RLB  
0
2
TPDE  
0
1
RPDE  
0
0
TE  
0
Bit 7 :Transmit AIS (TAIS) If this bit is set AIS is sent using MCLK as the reference clock. The data coming from  
the framer is replaced by all ones data.  
Bit 6 : Automatic Transmit AIS (ATAIS) If this bit is set AIS is sent using MCLK as the reference clock if there is  
a LOS. The data coming from the Framer is replaced by all ones data.  
Bit 5 : Local Loopback (LLB)  
Bit 4 : Analog Loopback (ALB)  
Bit 3 : Remote Loopback (RLB)  
Bit 2 : Transmit Power-Down Enable (TPDE) Setting this bit will power-down the transmit LIU and tri-state TTIP  
and TRING.  
Bit 1 : Receiver Power-Down Enable (RPDE) If this bit is set the receiver LIU for the transceiver is powered  
down.  
Bit 0 : Transmit Enable (TE ) If this bit is set the transmitter output for the transceiver is enabled. This function is  
overridden by the TXEnable pin. If it is low, the TTIP/TRING are always High-Z.  
Register Name:  
Register Description:  
Address (hex):  
LRSR  
LIU Real Status Register  
0803, 0A03, 0C03, 0E03  
Bit #  
Name  
Default  
7
-
0
6
-
0
5
OEQ  
0
4
UEQ  
0
3
-
0
2
SCS  
0
1
OCS  
0
0
LOSS  
0
Bits 7 to 6 : Unused.  
Bit 5 : (OEQ)  
Bit 4 : (UEQ)  
Bit 3 : Unused.  
Bit 2 : Open Circuit Status (OCS) If this bit is set, it indicates that there is an open circuit at the transmit driver for  
the transceiver. Please consult the factory for open circuit detection details if the transmitter is configured with  
impedance match on and CSU filters are selected.  
Bit 1 : Short Circuit Status (SCS) If this bit is set, it indicates that there is short circuit at the transmit driver for  
the transceiver. The short circuit resistance has to be 25Ω (typ) for short circuit detection  
Bit 0 : Loss of Signal Status (LOS) If this bit is set it indicates LOS for the transceiver.  
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Register Name:  
Register Description:  
Address (hex):  
LSIMR  
LIU Status Interrupt Mask Register  
0804, 0A04, 0C04, 0E04  
Bit #  
7
6
5
4
3
2
1
0
Name  
JALTRSIM OCSRIM  
SCSRI LOSRIM JALTSSI  
OCSSIM SCSSIM LOSSIM  
M
M
Default  
0
0
0
0
0
0
0
0
Bit 7 : Jitter Attenuator Limit Trip Reset Status Interrupt Mask (JALTRIM) If this bit is set, Jitter Attenuator  
Limit Trip Status reset can generate an Interrupt.  
Bit 6 : Open Circuit Status Reset Interrupt Mask (OCSRIM) If this bit is set, Open circuit Status reset can  
generate an Interrupt.  
Bit 5 : Short Circuit Status Reset Interrupt Mask (SCSRIM) If this bit is set, Short circuit Status reset can  
generate an Interrupt.  
Bit 4 : Loss of Signal Status Reset Interrupt Mask (LOSRIM) If this bit is set, LOS Status resets can generate  
an Interrupt.  
Bit 3 : Jitter Attenuator Limit Trip Set Status Interrupt Mask (JALTSSIM) If this bit is set, Jitter Attenuator Limit  
Trip Status changes can generate an Interrupt.  
Bit 2 : Open circuit Status Set Interrupt Mask (OCSSIM) If this bit is set, Open circuit Status changes can  
generate an Interrupt.  
Bit 1 : Short Circuit Status Set Interrupt Mask (SCSSIM) If this bit is set, Short circuit Status changes can  
generate an Interrupt.  
Bit 0 : Loss of Signal Status Set Interrupt Mask (LOSSIM) If this bit is set, LOS Status changes can generate  
an Interrupt.  
Register Name:  
Register Description:  
Address (hex):  
LLSR  
LIU Latched Status Register  
0805, 0A05, 0C05, 0E05  
Bit #  
Name  
7
6
OCRL  
S
5
SCRL  
S
4
3
2
1
0
JFLTRL  
LOSRL  
JALTSL OCSLS SCSLS LOSSLS  
S
S
S
Defaul  
t
0
0
0
0
0
0
0
0
Bit 7 : Jitter Attenuator Limit Trip Reset Latched Status (JALTRLS) This bit is set if Jitter Attenuator Trip  
Status bit reset.  
Bit 6 : Open Circuit Reset Latched Status (OCRLS) This bit is set if Open Circuit Status bit reset.  
Bit 5: Short Circuit Reset Latched Status (SCRLS) This bit is set if the Short Circuit Status bit reset.  
Bit 4 : Loss of Signal Reset Latched Status (LOSRLS) This bit is set if the Short Circuit Status bit reset.  
Bit 3 : Jitter Attenuator Limit Trip Set Latched Status (JFLTLS) This bit is set if the Jitter Attenuator Trip Status  
bit is set.  
Bit 2 : Open Circuit Set Latched Status (OCSLS) This bit is set when Open circuit status bit is set.  
Bit 1 : Short Circuit Set Latched Status (SCSLS) This bit is set when Short circuit status bit is set.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Bit 0 : Loss of Signal Set Latched Status (LOSSLS) This bit is set when LOS status bit is set.  
Register Name:  
Register Description:  
Address (hex):  
LRSL  
LIU Receive Signal Level  
0806, 0A06, 0C06, 0E06  
Bit #  
Name  
Default  
7
RSL3  
0
6
RSL2  
0
5
RLS1  
0
4
RLS0  
0
3
-
0
2
-
0
1
-
0
0
-
0
Bit 7 to 4 : Receiver Signal Level 3, 2, 1, and 0 (RSL3, RSL2, RSL1, RSL0) Receive Signal Level indication.  
These bits are only applicable in Long Haul Mode.  
Table 12-5 Receive Level Indication  
RSL3 RSL2 RSL1  
RSL0  
Receive Level (dB)  
T1  
Receive Level (dB)  
E1  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
>-2.5  
-2.5 to -5  
>-2.5  
-2.5 to -5  
-5 to –7.5  
-7.5 to -10  
-10 to –12.5  
-12.5 to -15  
-15 to –17.5  
-17.5 to -20  
-20 to –22.5  
-22.5 to -25  
-25 to –27.5  
-27.5 to -30  
-30 to -34  
<-34  
-5 to –7.5  
-7.5 to -10  
-10 to –12.5  
-12.5 to -15  
-15 to –17.5  
-17.5 to -20  
-20 to –22.5  
-22.5 to -25  
-25 to –27.5  
-27.5 to -30  
-30 to -34  
-34 to -38  
-38 to -43  
<-43  
Bits 3 to 0 : Unused.  
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Register Name:  
Register Description:  
Address (hex):  
LRCR  
LIU Receive Control Register  
0807, 0A07, 0C07, 0E07  
Bit #  
Name  
Default  
7
RG703  
0
6
IRTOFF  
0
5
IRTS1  
0
4
IRTS0  
0
3
RTTR  
0
2
RMME  
0
1
0
RSMGS1 RSMGS0  
0
0
Bit 7 : Receive G.703 Clock (RG703) When set = 1, the receiver expects a 2.048 MHz (E1 mode) or 1.544 MHz  
(T1 mode) synchronization clock (as specified by G.703) at RTIP/RRING.  
Bit 6 : Internal Receive Termination Off (IRTOFF) Disables the internal receive termination.  
0 = internal receive termination enabled, IRTS1 and IRTS0 select termination value  
1 = internal receive termination disabled.  
Bit 5 & 4 : Internal Receive Termination Select 1, 0 (IRTS1, IRTS0) These bits select the internal receive  
termination. These have to be set to match cable impedance. If the internal receive termination is disabled via  
IRTOFF, IRTS1 and IRTS2 should still be set to match the external cable characteristics for optimum operation.  
Table 12-6 Internal Receive Termination Selection  
INTERNAL RECEIVE  
TERMINATION (Ω)  
IRTS0  
IRTS1  
0
0
1
1
0
1
0
1
75  
100  
110  
120  
Bit 3 : Receive Transformer Turns Ratio (RTTR) This bit is used to select receive transformer turns ratio 1:1 or  
2:1 operation.  
0 = 1:1 turns ratio (normal mode)  
1 = 2:1 turns ratio (short haul applications only)  
Bit 2 : Receive Monitor Mode Enable (RMME) When set = 1, the receive monitor mode is enabled. A resistive  
gain will be added to the normal cable loss sensitivity. The resistive gain is determined by RSMGS1 and RSMGS0.  
Bits 1 & 0 : Receive Sensitivity / Monitor Gain Select 1, 0 (RSMGS1, RSMGS0) When RMME = 0, these bits  
are used to select the maximum receive sensitivity. When RMME = 1, these bits are used to select the receive  
monitor mode gain.  
Table 12-7 Monitor Gain and Maximum Receive Sensitivity Selection  
MAXIMUM RECEIVE  
SENSITIVITY  
RECEIVE MONITOR  
GAIN SETTINGS  
RMME  
RSMGS1 RSMGS0  
0
0
0
0
0
1
0
1
0
12 dB  
20 dB  
30 dB  
0
0
0
36 db for T1  
43 db for E1  
30 dB  
0
1
1
0
1
1
1
1
0
0
1
1
0
1
0
1
14  
20  
26  
32  
22.5 dB  
17.5 dB  
12 dB  
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13 BIT ERROR RATE TESTER (BERT)  
Table 13-1 BERT Register Map  
ADDRESS  
(hex)  
PORT 1 + 0h  
PORT 2 + 200h  
PORT 3 + 400h  
PORT 4 + 600h  
00E0  
NAME  
DESCRIPTION  
BERT Control Register  
Unused  
BCR  
--  
00E1  
00E2  
00E3  
00E4  
00E5  
00E6  
00E7  
00E8  
00E9  
BERT Pattern Configuration Register #1  
BERT Pattern Configuration Register #2  
BERT Seed/Pattern Register #1  
BERT Seed/Pattern Register #2  
BERT Seed/Pattern Register #3  
BERT Seed/Pattern Register #4  
Transmit Error Insertion Control Register  
Unused  
BPCR1  
BPCR2  
BSPR1  
BSPR2  
BSPR3  
BSPR4  
TEICR  
--  
00EA  
Unused  
--  
00EB  
00EC  
00ED  
00EE  
00EF  
00F0  
00F1  
00F2  
00F3  
00F4  
00F5  
00F6  
00F7  
00F8  
00F9  
00FA  
00FB  
00FC  
00FD  
00FE  
00FF  
Unused  
BERT Status Register  
Unused  
BERT Status Register Latched  
Unused  
BERT Status Register Interrupt Enable  
Unused  
--  
BSR  
--  
BSRL  
--  
BSRIE  
--  
--  
--  
Unused  
Unused  
Receive Bit Error Count Register #1  
Receive Bit Error Count Register #2  
Receive Bit Error Count Register #3  
Unused  
Receive Bit Count Register #1  
Receive Bit Count Register #2  
Receive Bit Count Register #3  
Receive Bit Count Register #4  
Unused  
RBECR1  
RBECR2  
RBECR3  
--  
RBCR1  
RBCR2  
RBCR3  
RBCR4  
--  
Unused  
Unused  
Unused  
--  
--  
--  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
13.1 BERT Register Bit Descriptions  
Register Name:  
BCR  
Register Description:  
Register Address:  
BERT Control Register  
E0h  
Bit #  
Name  
Default  
7
PMUM  
0
6
LPMU  
0
5
RNPL  
0
4
RPIC  
0
3
MPR  
0
2
APRD  
0
1
TNPL  
0
0
TPIC  
0
Bit 7/ Performance Monitoring Update Mode (PMUM) – When 0, a performance monitoring update is initiated by  
the LPMU register bit. When 1, a performance monitoring update is initiated by the receive performance monitoring  
update signal (RPMU). Note: If RPMU or LPMU is one, changing the state of this bit may cause a performance  
monitoring update to occur.  
Bit 6/ Local Performance Monitoring Update (LPMU) – This bit causes a performance monitoring update to be  
initiated if local performance monitoring update is enabled (PMUM = 0). A 0 to 1 transition causes the performance  
monitoring registers to be updated with the latest data, and the counters reset (0 or 1). For a second performance  
monitoring update to be initiated, this bit must be set to 0, and back to 1. If LPMU goes low before the PMS bit  
goes high, an update might not be performed. This bit has no affect when PMUM=1.  
Bit 5/ Receive New Pattern Load (RNPL) – A zero to one transition of this bit will cause the programmed test  
pattern (QRSS, PTS, PLF[4:0], PTF[4:0], and BSP[31:0]) to be loaded in to the receive pattern generator. This bit  
must be changed to zero and back to one for another pattern to be loaded. Loading a new pattern will forces the  
receive pattern generator out of the “Sync” state which causes a resynchronization to be initiated. Note: QRSS,  
PTS, PLF[4:0}, PTF[4:0], and BSP[31:0] must not change from the time this bit transitions from 0 to 1 until four  
RXCK clock cycles after this bit transitions from 0 to 1.  
Bit 4/ Receive Pattern Inversion Control (RPIC) – When 0, the receive incoming data stream is not altered.  
When 1, the receive incoming data stream is inverted.  
Bit 3/ Manual Pattern Resynchronization (MPR) – A zero to one transition of this bit will cause the receive  
pattern generator to resynchronize to the incoming pattern. This bit must be changed to zero and back to one for  
another resynchronization to be initiated. Note: A manual resynchronization forces the receive pattern generator  
out of the “Sync” state.  
Bit 2/ Automatic Pattern Resynchronization Disable (APRD) – When 0, the receive pattern generator will  
automatically resynchronize to the incoming pattern if six or more times during the current 64-bit window the  
incoming data stream bit and the receive pattern generator output bit did not match. When 1, the receive pattern  
generator will not automatically resynchronize to the incoming pattern. Note: Automatic synchronization is  
prevented by not allowing the receive pattern generator to automatically exit the “Sync” state.  
Bit 1/ Transmit New Pattern Load (TNPL) – A zero to one transition of this bit will cause the programmed test  
pattern (QRSS, PTS, PLF[4:0], PTF[4:0], and BSP[31:0]) to be loaded in to the transmit pattern generator. This bit  
must be changed to zero and back to one for another pattern to be loaded. Note: QRSS, PTS, PLF[4:0}, PTF[4:0],  
and BSP[31:0] must not change from the time this bit transitions from 0 to 1 until four TXCK clock cycles after this  
bit transitions from 0 to 1.  
Bit 0/ Transmit Pattern Inversion Control (TPIC) – When 0, the transmit outgoing data stream is not altered.  
When 1, the transmit outgoing data stream is inverted.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
BPCR1  
Register Description:  
Register Address:  
BERT Pattern Configuration Register #1  
E2h  
Bit #  
Name  
Default  
7
--  
0
6
QRSS  
0
5
PTS  
0
4
PLF4  
0
3
PLF3  
0
2
PLF2  
0
1
PLF1  
0
0
PLF0  
0
Bit 6/ QRSS Enable (QRSS) – When 0, the pattern generator configuration is controlled by PTS, PLF[4:0], and  
PTF[4:0], and BSP[31:0]. When 1, the pattern generator configuration is forced to a PRBS pattern with a  
generating polynomial of x20 + x17 + 1. The output of the pattern generator will be forced to one if the next fourteen  
output bits are all zero.  
Bit 5/ Pattern Type Select (PTS) – When 0, the pattern is a PRBS pattern. When 1, the pattern is a repetitive  
pattern.  
Bit 4-0/ Pattern Length Feedback (PLF[4:0]) – These five bits control the “length” feedback of the pattern  
generator. The “length” feedback will be from bit n of the pattern generator (n = PLF[4:0] +1). For a PRBS signal,  
the feedback is an XOR of bit n and bit y. For a repetitive pattern the feedback is bit n.  
Register Name:  
BPCR2  
Register Description:  
Register Address:  
BERT Pattern Configuration Register #2  
E3h  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
PTF4  
0
3
PTF3  
0
2
PTF2  
0
1
PTF1  
0
0
PTF0  
0
Bits 4 to 0: Pattern Tap Feedback (PTF[4:0]) – These five bits control the PRBS “tap” feedback of the pattern  
generator. The “tap” feedback will be from bit y of the pattern generator (y = PTF[4:0] +1). These bits are ignored  
when programmed for a repetitive pattern. For a PRBS signal, the feedback is an XOR of bit n and bit y.  
Register Name:  
BSPR1  
Register Description:  
Register Address:  
BERT Seed/Pattern Register #1  
E4h  
Bit #  
Name  
Default  
7
BSP7  
0
6
BSP6  
0
5
BSP5  
0
4
BSP4  
0
3
BSP3  
0
2
BSP2  
0
1
BSP1  
0
0
BSP0  
0
Bits 7 to 0: BERT Seed/Pattern (BSP[7:0])  
Register Name:  
BSPR2  
Register Description:  
Register Address:  
BERT Seed/Pattern Register #2  
E5h  
Bit #  
Name  
Default  
7
BSP15  
0
6
BSP14  
0
5
BSP13  
0
4
BSP12  
0
3
BSP11  
0
2
BSP10  
0
1
BSP9  
0
0
BSP8  
0
Bits 7 to 0: BERT Seed/Pattern (BSP[15:8])  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
BSPR3  
Register Description:  
Register Address:  
BERT Seed/Pattern Register #2  
E6h  
Bit #  
Name  
Default  
7
BSP23  
0
6
BSP22  
0
5
BSP21  
0
4
BSP20  
0
3
BSP19  
0
2
BSP18  
0
1
BSP17  
0
0
BSP16  
0
Bits 7 to 0: BERT Seed/Pattern (BSP[23:16])  
Register Name:  
BSPR4  
Register Description:  
Register Address:  
BERT Seed/Pattern Register #2  
E7h  
Bit #  
Name  
Default  
7
BSP31  
0
6
BSP30  
0
5
BSP29  
0
4
BSP28  
0
3
BSP27  
0
2
BSP26  
0
1
BSP25  
0
0
BSP24  
0
Bits 7 to 0: BERT Seed/Pattern (BSP[31:24])  
BERT Seed/Pattern (BSP[31:0]) – These 32 bits are the programmable seed for a transmit PRBS pattern, or the  
programmable pattern for a transmit or receive repetitive pattern. BSP(31) will be the first bit output on the transmit  
side for a 32-bit repetitive pattern or 32-bit length PRBS. BSP(31) will be the first bit input on the receive side for a  
32-bit repetitive pattern.  
Register Name:  
TEICR  
Register Description:  
Register Address:  
Transmit Error Insertion Control Register  
E8h  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
TEIR2  
0
4
TEIR1  
0
3
TEIR0  
0
2
BEI  
0
1
TSEI  
0
0
--  
0
Bit 5-3/ Transmit Error Insertion Rate (TEIR[2:0]) – These three bits indicate the rate at which errors are  
inserted in the output data stream. One out of every 10n bits is inverted. TEIR[2:0] is the value n. A TEIR[2:0] value  
of 0 disables error insertion at a specific rate. A TEIR[2:0] value of 1 result in every 10th bit being inverted. A  
TEIR[2:0] value of 2 result in every 100th bit being inverted. Error insertion starts when this register is written to with  
a TEIR[2:0] value that is non-zero. If this register is written to during the middle of an error insertion process, the  
new error rate will be started after the next error is inserted.  
Bit 2/ Bit Error Insertion Enable (BEI) – When 0, single bit error insertion is disabled. When 1, single bit error  
insertion is enabled.  
Bit 1/ Transmit Single Error Insert (TSEI) – This bit causes a bit error to be inserted in the transmit data stream if  
manual error insertion is disabled (MEIMS = 0) and single bit error insertion is enabled. A 0 to 1 transition causes a  
single bit error to be inserted. For a second bit error to be inserted, this bit must be set to 0, and back to 1. Note: If  
MEIMS is low, and this bit transitions more than once between error insertion opportunities, only one error will be  
inserted.  
Bit 0 – Unused. This bit should be set to zero for proper operation.  
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Register Name:  
BSR  
Register Description:  
Register Address:  
BERT Status Register  
ECh  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
PMS  
0
2
--  
0
1
BEC  
0
0
OOS  
0
Bit 3/ Performance Monitoring Update Status (PMS) – This bit indicates the status of the receive performance  
monitoring register (counters) update. This bit will transition from low to high when the update is completed. PMS is  
asynchronously forced low when the LPMU bit (PMUM = 0) or RPMU signal (PMUM=1) goes low.  
Bit 1/ Bit Error Count (BEC) – When 0, the bit error count is zero. When 1, the bit error count is one or more.  
Bit 0/ Out Of Synchronization (OOS) – When 0, the receive pattern generator is synchronized to the incoming  
pattern. When 1, the receive pattern generator is not synchronized to the incoming pattern.  
Register Name:  
BSRL  
Register Description:  
Register Address:  
BERT Status Register Latched  
EEh  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
PMSL  
0
2
BEL  
0
1
BECL  
0
0
OOSL  
0
Bit 3/ Performance Monitoring Update Status Latched (PMSL) – This bit is set when the PMS bit transitions  
from 0 to 1.  
Bit 2/ Bit Error Latched (BEL) – This bit is set when a bit error is detected.  
Bit 1/ Bit Error Count Latched (BECL) – This bit is set when the BEC bit transitions from 0 to 1.  
Bit 0/ Out Of Synchronization Latched (OOSL) – This bit is set when the OOS bit changes state.  
Register Name:  
BSRIE  
Register Description:  
Register Address:  
BERT Status Register Interrupt Enable  
F0h  
Bit #  
Name  
Default  
7
--  
0
6
--  
0
5
--  
0
4
--  
0
3
PMSIE  
0
2
BEIE  
0
1
BECIE  
0
0
OOSIE  
0
Bit 3/ Performance Monitoring Update Status Interrupt Enable (PMSIE) – This bit enables an interrupt if the  
PMSL bit is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 2/ Bit Error Interrupt Enable (BEIE) – This bit enables an interrupt if the BEL bit is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 1/ Bit Error Count Interrupt Enable (BECIE) – This bit enables an interrupt if the BECL bit is set.  
0 = interrupt disabled  
1 = interrupt enabled  
Bit 0/ Out Of Synchronization Interrupt Enable (OOSIE) – This bit enables an interrupt if the OOSL bit is set.  
0 = interrupt disabled  
1 = interrupt enabled  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Register Name:  
RBECR1  
Register Description:  
Register Address:  
Receive Bit Error Count Register #1  
F4h  
Bit #  
Name  
Default  
7
BEC7  
0
6
BEC6  
0
5
BEC5  
0
4
BEC4  
0
3
BEC3  
0
2
BEC2  
0
1
BEC1  
0
0
BEC0  
0
Bits 7 to 0: Bit Error Count (BEC[7:0])  
Register Name:  
RBECR2  
Register Description:  
Register Address:  
Receive Bit Error Count Register #2  
F5h  
Bit #  
Name  
Default  
7
BEC15  
0
6
BEC14  
0
5
BEC13  
0
4
BEC12  
0
3
BEC11  
0
2
BEC10  
0
1
BEC9  
0
0
BEC8  
0
Bits 7 to 0: Bit Error Count (BEC[15:8])  
Register Name:  
RBECR3  
Register Description:  
Register Address:  
Receive Bit Error Count Register #3  
F6h  
Bit #  
Name  
Default  
7
BEC23  
0
6
BEC22  
0
5
BEC21  
0
4
BEC20  
0
3
BEC19  
0
2
BEC18  
0
1
BEC17  
0
0
BEC16  
0
Bits 7 to 0: Bit Error Count (BEC[23:16])  
Bit Error Count (BEC[23:0]) – These twenty-four bits indicate the number of bit errors detected in the incoming  
data stream. This count stops incrementing when it reaches a count of FF FFFFh. The associated bit error counter  
will not incremented when an OOS condition exists.  
Register Name:  
RBCR1  
Register Description:  
Register Address:  
Receive Bit Count Register #1  
F8h  
Bit #  
Name  
Default  
7
BC7  
0
6
BC6  
0
5
BC5  
0
4
BC4  
0
3
BC3  
0
2
BC2  
0
1
BC1  
0
0
BC0  
0
Bits 7 to 0: Bit Count (BC[7:0])  
Register Name:  
RBCR2  
Register Description:  
Register Address:  
Receive Bit Count Register #2  
F9h  
Bit #  
Name  
Default  
7
BC15  
0
6
BC14  
0
5
BC13  
0
4
BC12  
0
3
BC11  
0
2
BC10  
0
1
BC9  
0
0
BC8  
0
Bits 7 to 0: Bit Count (BC[15:8])  
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Register Name:  
RBCR3  
Register Description:  
Register Address:  
Receive Bit Count Register #3  
FAh  
Bit #  
Name  
Default  
7
BC23  
0
6
BC22  
0
5
BC21  
0
4
BC20  
0
3
BC19  
0
2
BC18  
0
1
BC17  
0
0
BC16  
0
Bits 7 to 0: Bit Count (BC[23:16])  
Register Name:  
RBCR4  
Register Description:  
Register Address:  
Receive Bit Count Register #4  
FBh  
Bit #  
Name  
Default  
15  
BC31  
0
14  
BC30  
0
13  
BC29  
0
12  
BC28  
0
11  
BC27  
0
10  
BC26  
0
9
BC25  
0
8
BC24  
0
Bits 7 to 0: Bit Count (BC[31:24])  
Bit Count (BC[31:0]) – These thirty-two bits indicate the number of bits in the incoming data stream. This count  
stops incrementing when it reaches a count of FFFF FFFFh. The associated bit counter will not incremented when  
an OOS condition exists.  
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14 JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT  
The DS26556 JTAG port supports the standard instruction codes SAMPLE/PRELOAD, BYPASS, and EXTEST.  
Optional public instructions included are HIGHZ, CLAMP, and IDCODE. The DS26556 contains the following, as  
required by IEEE 1149.1 Standard Test Access Port and Boundary Scan Architecture:  
Test Access Port (TAP)  
TAP Controller  
Instruction Register  
Bypass Register  
Boundary Scan Register  
Device Identification Register  
The Test Access Port has the necessary interface pins JTRST, JTCLK, JTMS, JTDI, and JTDO. See the pin  
descriptions for details.  
Figure 14-1 JTAG Functional Block Diagram  
BOUNDRY SCAN  
REGISTER  
IDENTIFICATION  
REGISTER  
MUX  
BYPASS  
REGISTER  
INSTRUCTION  
REGISTER  
TEST ACCESS PORT  
CONTROLLER  
SELECT  
OUTPUT ENABLE  
VDD  
VDD  
VDD  
10kΩ  
10kΩ  
10kΩ  
JTDI  
JTMS  
JTCLK  
JTDO  
JTRST  
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14.1 TAP Controller State Machine  
The TAP controller is a finite state machine that responds to the logic level at JTMS on the rising edge of JTCLK.  
See Figure 14-2.  
Figure 14-2 TAP Controller State Diagram  
Test Logic  
Reset  
1
0
1
1
1
Run Test/  
Idle  
Select  
DR-Scan  
Select  
IR-Scan  
0
0
0
1
1
Capture DR  
Capture IR  
0
0
Shift DR  
Shift IR  
0
1
0
1
1
1
Exit DR  
Exit IR  
0
0
Pause DR  
Pause IR  
0
0
1
1
0
0
Exit2 DR  
Exit2 IR  
1
1
Update DR  
Update IR  
1
0
1
0
Test-Logic-Reset  
Upon power up, the TAP Controller will be in the Test-Logic-Reset state. The Instruction register will contain the  
IDCODE instruction. All system logic of the device will operate normally.  
Run-Test-Idle  
The Run-Test-Idle is used between scan operations or during specific tests. The Instruction register and test  
registers will remain idle.  
Select-DR-Scan  
All test registers retain their previous state. With JTMS LOW, a rising edge of JTCLK moves the controller into the  
Capture-DR state and will initiate a scan sequence. JTMS HIGH during a rising edge on JTCLK moves the  
controller to the Select-IR-Scan state.  
Capture-DR  
Data may be parallel-loaded into the test data registers selected by the current instruction. If the instruction does  
not call for a parallel load or the selected register does not allow parallel loads, the test register will remain at its  
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current value. On the rising edge of JTCLK, the controller will go to the Shift-DR state if JTMS is LOW or it will go  
to the Exit1-DR state if JTMS is HIGH.  
Shift-DR  
The test data register selected by the current instruction will be connected between JTDI and JTDO and will shift  
data one stage towards its serial output on each rising edge of JTCLK. If a test register selected by the current  
instruction is not placed in the serial path, it will maintain its previous state.  
Exit1-DR  
While in this state, a rising edge on JTCLK will put the controller in the Update-DR state, which terminates the  
scanning process, if JTMS is HIGH. A rising edge on JTCLK with JTMS LOW will put the controller in the Pause-  
DR state.  
Pause-DR  
Shifting of the test registers is halted while in this state. All test registers selected by the current instruction will  
retain their previous state. The controller will remain in this state while JTMS is LOW. A rising edge on JTCLK with  
JTMS HIGH will put the controller in the Exit2-DR state.  
Exit2-DR  
A rising edge on JTCLK with JTMS HIGH while in this state will put the controller in the Update-DR state and  
terminate the scanning process. A rising edge on JTCLK with JTMS LOW will enter the Shift-DR state.  
Update-DR  
A falling edge on JTCLK while in the Update-DR state will latch the data from the shift register path of the test  
registers into the data output latches. This prevents changes at the parallel output due to changes in the shift  
register.  
Select-IR-Scan  
All test registers retain their previous state. The instruction register will remain unchanged during this state. With  
JTMS LOW, a rising edge on JTCLK moves the controller into the Capture-IR state and will initiate a scan  
sequence for the instruction register. JTMS HIGH during a rising edge on JTCLK puts the controller back into the  
Test-Logic-Reset state.  
Capture-IR  
The Capture-IR state is used to load the shift register in the instruction register with a fixed value. This value is  
loaded on the rising edge of JTCLK. If JTMS is HIGH on the rising edge of JTCLK, the controller will enter the  
Exit1-IR state. If JTMS is LOW on the rising edge of JTCLK, the controller will enter the Shift-IR state.  
Shift-IR  
In this state, the shift register in the instruction register is connected between JTDI and JTDO and shifts data one  
stage for every rising edge of JTCLK towards the serial output. The parallel register and all test registers remain at  
their previous states. A rising edge on JTCLK with JTMS HIGH will move the controller to the Exit1-IR state. A  
rising edge on JTCLK with JTMS LOW will keep the controller in the Shift-IR state while moving data one stage  
thorough the instruction shift register.  
Exit1-IR  
A rising edge on JTCLK with JTMS LOW will put the controller in the Pause-IR state. If JTMS is HIGH on the rising  
edge of JTCLK, the controller will enter the Update-IR state and terminate the scanning process.  
Pause-IR  
Shifting of the instruction shift register is halted temporarily. With JTMS HIGH, a rising edge on JTCLK will put the  
controller in the Exit2-IR state. The controller will remain in the Pause-IR state if JTMS is LOW during a rising edge  
on JTCLK.  
Exit2-IR  
A rising edge on JTCLK with JTMS LOW will put the controller in the Update-IR state. The controller will loop back  
to Shift-IR if JTMS is HIGH during a rising edge of JTCLK in this state.  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Update-IR  
The instruction code shifted into the instruction shift register is latched into the parallel output on the falling edge of  
JTCLK as the controller enters this state. Once latched, this instruction becomes the current instruction. A rising  
edge on JTCLK with JTMS LOW puts the controller in the Run-Test-Idle state. With JTMS HIGH, the controller  
enters the Select-DR-Scan state.  
14.2 Instruction Register  
The instruction register contains a shift register as well as a latched parallel output and is 3 bits in length. When  
the TAP controller enters the Shift-IR state, the instruction shift register will be connected between JTDI and JTDO.  
While in the Shift-IR state, a rising edge on JTCLK with JTMS LOW will shift the data one stage towards the serial  
output at JTDO. A rising edge on JTCLK in the Exit1-IR state or the Exit2-IR state with JTMS HIGH will move the  
controller to the Update-IR state. The falling edge of that same JTCLK will latch the data in the instruction shift  
register to the instruction parallel output. Instructions supported by the DS26556 and its respective operational  
binary codes are shown in Table 14-1.  
Table 14-1 Instruction Codes for IEEE 1149.1 Architecture  
INSTRUCTION  
SAMPLE/PRELOAD  
BYPASS  
SELECTED REGISTER  
Boundary Scan  
Bypass  
Boundary Scan  
Bypass  
Bypass  
Device Identification  
INSTRUCTION CODES  
010  
111  
000  
011  
100  
001  
EXTEST  
CLAMP  
HIGHZ  
IDCODE  
SAMPLE/PRELOAD  
This is a mandatory instruction for the IEEE 1149.1 specification. This instruction supports two functions. The  
digital I/Os of the device can be sampled at the boundary scan register without interfering with the normal  
operation of the device by using the Capture-DR state. SAMPLE/PRELOAD also allows the device to shift data into  
the boundary scan register via JTDI using the Shift-DR state.  
BYPASS  
When the BYPASS instruction is latched into the parallel instruction register, JTDI connects to JTDO through the  
one-bit bypass test register. This allows data to pass from JTDI to JTDO not affecting the device’s normal  
operation.  
EXTEST  
This allows testing of all interconnections to the device. When the EXTEST instruction is latched in the instruction  
register, the following actions occur. Once enabled via the Update-IR state, the parallel outputs of all digital output  
pins will be driven. The boundary scan register will be connected between JTDI and JTDO. The Capture-DR will  
sample all digital inputs into the boundary scan register.  
CLAMP  
All digital outputs of the device will output data from the boundary scan parallel output while connecting the bypass  
register between JTDI and JTDO. The outputs will not change during the CLAMP instruction.  
HIGHZ  
All digital outputs of the device will be placed in a high-impedance state. The BYPASS register will be connected  
between JTDI and JTDO.  
IDCODE  
When the IDCODE instruction is latched into the parallel instruction register, the identification test register is  
selected. The device identification code will be loaded into the identification register on the rising edge of JTCLK  
following entry into the Capture-DR state. Shift-DR can be used to shift the identification code out serially via  
JTDO. During Test-Logic-Reset, the identification code is forced into the instruction register’s parallel output. The  
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DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
ID code will always have a ‘1’ in the LSB position. The next 11 bits identify the manufacturer’s JEDEC number and  
number of continuation bytes followed by 16 bits for the device and 4 bits for the version.  
Table 14-2 ID Code Structure  
MSB  
LSB (Must be '1')  
Version (contact factory)  
4 bits  
Device ID (0038h)  
0000000000111000  
JEDEC  
00010100001  
1
1
14.3 Test Registers  
IEEE 1149.1 requires a minimum of two test registers—the bypass register and the boundary scan register. An  
optional test register, the identification register, has been included with the DS26556 design. The identification  
register is used in conjunction with the IDCODE instruction and the Test-Logic-Reset state of the TAP controller.  
Boundary Scan Register  
This register contains a shift register path and a latched parallel output for all control cells and digital I/O cells. It is  
n bits in length.  
Bypass Register  
The bypass register is a single one-bit shift register used with the BYPASS, CLAMP, and HIGHZ instructions,  
which provide a short path between JTDI and JTDO.  
Identification Register  
The identification register contains a 32-bit shift register and a 32-bit latched parallel output. This register is  
selected during the IDCODE instruction and when the TAP controller is in the Test-Logic-Reset state.  
352 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
15 PIN ASSIGNMENT  
Figure 15-1 DS26556 Pin Assignments—256-Lead BGA  
1
2
3
4
5
RSYNC2  
RSER2  
TCLK1  
TSERO1  
RSER1  
RLOF_LOTC1  
VDD  
6
7
8
9
10  
11  
WR  
12  
TADR0  
INT  
13  
14  
RDXA3  
NC  
15  
NC  
16  
TTIP1  
TVDD1  
RTIP1  
RVDD1  
RVDD2  
RTIP2  
TVDD2  
TTIP2  
TTIP3  
TVDD3  
RTIP3  
RVDD3  
RVDD4  
RTIP4  
TVDD4  
TTIP4  
STTIP1  
TVSS1  
RRING1  
RVSS1  
RVSS2  
RRING2  
TVSS2  
STTIP2  
STTIP3  
TVSS3  
RRING3  
RVSS3  
RVSS4  
RRING4  
TVSS4  
STTIP4  
TRING1  
TSERI1  
TCLK2  
TCHMRK2  
RCHMRK2  
TSERO2  
RCLKO2  
TCHMRK1  
VDD  
ADDR7  
ADDR8  
ADDR9  
ADDR10  
ADDR11  
ADDR12  
VDD  
ADDR4  
ADDR3  
ADDR5  
ADDR2  
ADDR6  
ADDR1  
VDD  
REFCLK  
ADDR0  
MCLK  
DATA4  
DATA5  
DATA3  
DATA2  
DATA1  
DATA0  
VDD  
TADR4  
TADR2  
TEN  
RDXA4  
TDXA3  
TSPA  
A
B
C
D
E
F
G
H
J
STRING1  
TSYNC1  
RSYNC1  
TSYNC2  
TSERI2  
STRING2  
TRING2  
TRING3  
STRING3  
RLOS4  
RCHMRK1  
RCLKO1  
CS  
RDXA2  
TDXA1  
RDXA1  
RVAL  
RPAR  
REOP  
NC  
RD  
TPAR  
TADR3  
TDAT8  
RSOX  
VDD  
TDXA2  
REN  
GTEST1  
BPCLK  
DATA7  
DATA6  
VDD  
BTS  
TDAT9  
RERR  
TSCLK  
NC  
GTEST2  
TADR1  
TDXA4  
VDD  
VSS  
RLOS1  
RMOD  
RDAT11  
RDAT15  
RDAT6  
RADR3  
TDAT4  
TDAT5  
TDAT7  
TDAT10  
TDAT12  
TDAT11  
TMOD  
NC  
RDAT0  
RDAT2  
RDAT1  
RDAT4  
RDAT3  
RDAT8  
RDAT7  
RDAT12  
RADR2  
TDAT3  
TDAT2  
RLOF_LOTC2  
RLOS2  
VDD  
VDD  
VDDCC  
VDD  
VSSCC  
VSS  
VDD  
VDD  
VDD  
RDAT14  
RADR4  
VSS  
RSCLK  
RDAT5  
NC  
RM_RFSYNC1  
RM_RFSYNC2  
RM_RFSYNC4  
RLOS3  
VSS  
VSS  
VSS  
VSS  
VSS  
NC  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
RDAT10  
RDAT9  
RDAT13  
RADR0  
RADR1  
TDAT0  
NC  
K
L
RM_RFSYNC3 RLOF_LOTC3  
RSYNC3  
TTEST3  
TTEST2  
SCAN_EN  
RESET  
TTEST1  
HSYSCLK  
HSSYNC  
HTSIG  
HRDATA  
HRSIG  
JTDO  
JTDI  
RLCD4  
ROCD1  
RLCD3  
RLCD2  
ROCD4  
RLCD1  
TDAT6  
TDAT15  
TERR  
TSOX  
TSX  
TDAT14  
TDAT13  
RCLKO4  
RCLKO3  
HIZ  
TXENABLE  
TCHMRK4  
TSYNC4  
RSYNC4  
RSER4  
TSERO4  
RCHMRK3  
TSERO3  
TSYNC3  
TSERI3  
M
N
P
R
T
TCLK3  
RLOF_LOTC4  
TCLK4  
RSER3  
RTEST3  
RTEST1  
ROCD3  
ROCD2  
NC  
TCHMRK3  
STRING4  
TRING4  
JTRST  
JTCLK  
JTMS  
TSERI4  
RCHMRK4  
RTEST2 SCAN_MODE HTDATA  
TEOP  
TDAT1  
353 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
16 PACKAGE MECHANICAL INFORMATION  
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package  
outline information, go to www.maxim-ic.com/DallasPackInfo.)  
NOTES:  
1. DIMENSION IS MM.  
2. THE BASIC SOLDER BALL GRID PITCH IS 1.00 MM.  
3. DIMENSION IS MEASURED AT THE MAXIMUM SOLDER BALL DIAMETER,  
PARALLEL TO PRIMARY DATUM C.  
4. PRIMARY DATUM C AND SEATING PLANE ARE DEFINED BY THE SPHERICAL CROWNS  
OF THE SOLDER BALLS.  
5. A1 BALL PAD CORNER ID  
354 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
17 PACKAGE THERMAL INFORMATION  
Table 17-1 Thermal Characteristics  
PARAMETER  
MIN  
TYP  
MAX  
Ambient Temperature (Note 1)  
Junction Temperature  
-
-
-40°C  
+85°C  
+125°C  
-
-
-
17.5  
Theta-JA (θJA) in Still Air for 10mm CSBGA  
The package is mounted on a four-layer JEDEC standard test board.  
Note 1:  
Note 2:  
Theta-JA (θJA) is the junction-to-ambient thermal resistance, when the package is mounted on a four-layer  
JEDEC standard test board.  
355 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
18 ABSOLUTE MAXIMUM RATINGS  
Table 18-1 Absolute Maximum Ratings  
Voltage Range on Any Pin Relative to Ground  
Operating Temperature Range for DS26556  
Operating Temperature Range for DS26556N  
Storage Temperature Range  
-1.0V to +6.0V  
0°C to +70°C  
-40°C to +85°C  
-55°C to +125°C  
See IPC/JEDEC J-STD-020 Standard  
Soldering Temperature  
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation  
sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect reliability.  
Table 18-2 Recommended DC Operating Conditions  
(TA = 0°C to +70°C for DS26556; TA = -40°C to +85°C for DS26556N.)  
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
Logic 1  
Logic 0  
Supply  
VIH  
VIL  
VDD  
2.0  
-0.3  
3.135  
5.5  
+0.8  
3.465  
V
V
V
3.3  
(Note 1)  
Table 18-3 Capacitance  
(TA = +25°C)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
Input Capacitance  
Output Capacitance  
CIN  
COUT  
5
7
pF  
pF  
Table 18-4 DC Operating Characteristics  
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26556; VDD = 3.3V ±5%, TA = -40°C to +85°C for DS26556N.)  
PARAMETER  
SYMBOL  
CONDITIONS  
MIN TYP  
MAX  
UNITS  
Supply Current  
Input Leakage  
Output Leakage  
Output Current (2.4V)  
Output Current (0.4V)  
IDD  
IIL  
ILO  
IOH  
IOL  
(Note 1)  
(Note 2)  
(Note 3)  
300  
-1.0  
mA  
μA  
μA  
mA  
mA  
+1.0  
1.0  
-1.0  
+4.0  
Measured with all four ports operating in E1 LBO 0 mode with a 50% ones density and the system interface  
operating at 52MHz.  
Note 1:  
0.0V < VIN < VDD  
.
Note 2:  
Note 3:  
Applied to INT when tri-stated.  
356 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19 AC TIMING  
Unless otherwise noted, all timing numbers assume 25pF test load on output signals, 40pF test load on bus  
signals.  
There are several common AC characteristic definitions. These generic definitions are shown below in Figure 19-1,  
Figure 19-2, Figure 19-3, and Figure 19-4. Definitions that are specific to a given interface are shown in that  
interface’s subsection.  
Figure 19-1 Clock Period and Duty Cycle Definitions  
t1  
Clock  
t2  
t2  
Figure 19-2 Rise Time, Fall Time, and Jitter Definitions  
t1  
t4/2  
Clock  
t4  
t3  
t3  
Figure 19-3 Hold, Setup, and Delay Definitions (Rising Clock Edge)  
Clock  
t5  
t6  
Din  
t7  
Dout  
357 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 19-4 Hold, Setup, and Delay Definitions (Falling Clock Edge)  
Clock  
Din  
t5  
t6  
t7  
Dout  
Figure 19-5 To/From High-Z Delay Definitions (Rising Clock Edge)  
Clock  
t8  
t9  
Dout  
Figure 19-6 To/From High-Z Delay Definitions (Falling Clock Edge)  
Clock  
t8  
t9  
Dout  
358 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.1 Transmit TDM Port AC Characteristics  
All AC timing characteristics are specified with a 25 pF capacitive load on all output pins, VIH = 2.4V and VIL = 0.8V.  
The voltage threshold for all timing measurements is VDD/2. The generic timing definitions shown in Figure 19-1,  
Figure 19-2, Figure 19-3, and Figure 19-6 apply to this interface.  
Table 19-1 Transmit TDM Port Timing  
(VDD = 3.3V ±5%, Tj = -40°C to +85°C.)  
PARAMETER  
SYMBOL  
CONDITIONS  
T1 mode  
E1 mode  
MIN  
TYP  
648  
488  
MAX  
UNITS  
ns  
t1  
t1  
TCLK Period  
ns  
TCLK Clock Duty Cycle (t2/t1)  
t2/t1  
125  
20  
ns  
TSERI, TSYNC to TCLK Setup Time  
t5  
t6  
t7  
ns  
ns  
ns  
TCLK to TSERI, TSYNC Hold Time  
20  
TCLK to TSERO, TSYNC, TCHMRK  
Delay  
50  
359 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.2 Receive TDM Port AC Characteristics  
All AC timing characteristics are specified with a 25 pF capacitive load on all output pins, VIH = 2.4V and VIL = 0.8V.  
The voltage threshold for all timing measurements is VDD/2. The generic timing definitions shown in Figure 19-1,  
Figure 19-2, Figure 19-3, and Figure 19-6 apply to this interface.  
Table 19-2 Receive TDM Port Timing  
(VDD = 3.3V ±5%, Tj = -40°C to +85°C.)  
PARAMETER  
SYMBOL  
CONDITIONS  
T1 mode  
E1 mode  
MIN  
TYP  
648  
488  
MAX  
UNITS  
ns  
t1  
t1  
RCLKO Period  
ns  
RCLKO Clock Duty Cycle (t2/t1)  
t2/t1  
125  
ns  
RCLKO to RSER, RSYNC,  
RM_RFSYNC, RCHMRK Delay  
t7  
50  
ns  
360 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.3 High Speed Port AC Characteristics  
All AC timing characteristics are specified with a 25 pF capacitive load on all output pins, VIH = 2.4V and VIL = 0.8V.  
The voltage threshold for all timing measurements is VDD/2. The generic timing definitions shown in Figure 19-1,  
Figure 19-2, Figure 19-3, and Figure 19-6 apply to this interface.  
Table 19-3 Receive TDM Port Timing  
(VDD = 3.3V ±5%, Tj = -40°C to +85°C.)  
PARAMETER  
SYMBOL  
CONDITIONS  
T1 mode  
E1 mode  
MIN  
60  
TYP  
MAX  
UNITS  
ns  
t1  
t1  
HSYSCLK Period  
60  
ns  
HSYSCLK Clock Duty Cycle (t2/t1)  
t2/t1  
30  
ns  
HTDATA, HTSIG, HSSYNC to HSYSCLK  
Setup Time  
t5  
t6  
t7  
20  
20  
ns  
ns  
ns  
HSYSCLK to HTDATA, HTSIG, HSSYNC  
Hold Time  
HSYSCLK to HRDATA, HRSIG, HSSYNC  
Delay  
50  
361 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.4 System Interface AC Characteristics  
The generic timing definitions shown in Figure 19-1, Figure 19-2, Figure 19-3, and Figure 19-6 apply to this  
interface.  
Table 19-4 System Interface Level 2 Timing  
(VDD = 3.3V ±5%, Tj = -40°C to +125°C.)  
SIGNAL NAME(S)  
RSCLK and TSCLK  
RSCLK and TSCLK  
RSCLK and TSCLK  
RADR and REN  
SYMBOL  
DESCRIPTION  
Clock frequency (1/t1) (Note 1)  
Clock duty cycle (Note 1)  
MIN  
0
TYP  
MAX  
52  
UNITS  
MHz  
%
f1  
t2/t1  
t3  
40  
50  
60  
Rise/fall times (Notes 1, 2)  
Hold time from RSCLK (Note 1)  
Setup time to RSCLK (Note 1)  
2
ns  
t5  
0
ns  
t6  
3.5  
ns  
RADR and REN  
RDATA, RPRTY, RPXA,  
RSOX, REOP, RVAL,  
RMOD, and RERR  
RDATA, RPRTY, RPXA,  
RSOX, REOP, RVAL,  
RMOD, and RERR  
RDATA, RPRTY, RPXA,  
RSOX, REOP, RVAL,  
RMOD, and RERR  
TDATA, TPRTY, TADR,  
TEN, TSOX, TEOP,  
TMOD, and TERR  
t7  
t8  
t9  
t5  
t6  
Delay from RSCLK (Notes 1, 3)  
2
2
12  
12  
15  
ns  
ns  
ns  
ns  
ns  
From high-Z delay from RSCLK  
(Notes 1, 3)  
To high-Z delay from RSCLK  
(Notes 1, 3)  
2
Hold time from TSCLK (Note 1)  
0
TDATA, TPRTY, TADR,  
TEN, TSOX, TEOP,  
TMOD, and TERR  
Setup time to TSCLK (Note 1)  
Delay from TSCLK (Notes 1, 3)  
3.5  
TPXA and TSPA  
t7  
t8  
2
2
12  
12  
ns  
ns  
From high-Z delay from TSCLK  
(Notes 1, 3)  
TPXA and TSPA  
To high-Z delay from TSCLK  
(Notes 1, 3)  
TPXA and TSPA  
t9  
2
15  
ns  
The input/output timing reference level for all signals is VDD/2.  
Rise and fall times are measured at output side with the output unloaded. Rise time is measured from 20% to 80% VOH. Fall time  
is measured from 80% to 20% VOH  
Note 1:  
Note 2:  
.
Note 3:  
These times are met with a 30pF, 300Ω load on the associated output pin.  
362 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Table 19-5 System Interface Level 3 Timing  
(VDD = 3.3V ±5%, Tj = -40°C to +125°C.)  
SIGNAL NAME(S)  
SYMBOL  
DESCRIPTION  
MIN TYP MAX UNITS NOTES  
RSCLK and TSCLK  
RSCLK and TSCLK  
RSCLK and TSCLK  
RADR and REN  
f1  
t2/t1  
t3  
Clock Frequency (1/t1)  
Clock Duty Cycle  
0
52  
60  
2
MHz  
%
1
1
40  
50  
Rise/Fall Times  
ns  
1,2  
1
t5  
Hold Time from RSCLK  
Setup Time to RSCLK  
0
ns  
t6  
3.5  
ns  
1
RADR and REN  
RDATA, RPRTY,  
RPXA, RSOX, REOP,  
RVAL, RMOD, and  
RERR  
TDATA, TPRTY,  
TADR, TEN, TSOX,  
TEOP, TMOD, and  
TERR  
t7  
t5  
Delay from RSCLK  
2
0
12  
ns  
ns  
1,3  
1
Hold Time from TSCLK  
TDATA, TPRTY,  
TADR, TEN, TSOX,  
TEOP, TMOD, and  
TERR  
t6  
t7  
Setup Time to TSCLK  
Delay from TSCLK  
3.5  
2
ns  
ns  
1
TPXA and TSPA  
12  
1,3  
The input/output timing reference level for all signals is VDD/2.  
Rise and fall times are measured at output side with the output unloaded. Rise time is measured from 20% to 80% VOH. Fall time  
is measured from 80% to 20% VOH  
Note 1:  
Note 2:  
.
Note 3:  
These times are met with a 30pF, 300Ω load on the associated output pin.  
363 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.5 Microprocessor Bus AC Characteristics  
Table 19-6 AC Characteristics—Microprocessor Bus Timing  
(VDD = 3.3V ±5%, TA = 0°C to +70°C for DS26556; VDD = 3.3V ± 5%, TA = -40°C to +85°C for DS26556N.)  
(Figure 19-7, Figure 19-8, Figure 19-9, and Figure 19-10)  
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP MAX UNITS  
Setup Time for ADDR[12:0] Valid to  
CS Active  
t1  
(Note 1)  
0
ns  
Setup Time for CS Active to Either RD  
or WR Active  
t2  
t3  
t4  
t5  
(Note 1)  
0
ns  
Delay Time from Either RD or DS  
Active to D[7:0] Valid  
115  
20  
ns  
ns  
ns  
Hold Time from Either RD or WR  
Inactive to CS Inactive  
0
Hold Time from CS or RD or DS  
Inactive to DATA[7:0] Tri-State  
2.5  
Wait Time from WR Active to Latch  
Data  
t6  
t7  
t8  
t9  
35  
10  
2
ns  
ns  
ns  
ns  
Data Set Up Time to WR Inactive  
Data Hold Time from WR Inactive  
Address Hold from WR Inactive  
3
Write Access to Subsequent  
Write/Read Access Delay Time  
t10  
80  
ns  
Note 1: Guaranteed by design.  
364 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 19-7 Intel Bus Read Timing (BTS = 0)  
ADDR[12:0]  
DATA[7:0]  
Address Valid  
Data Valid  
t5  
WR  
CS  
t1  
t2  
t3  
t4  
RD*  
t10  
Figure 19-8 Intel Bus Write Timing (BTS = 0)  
Address Valid  
ADDR[12:0]  
DATA[7:0]  
RD  
t7  
t8  
t1  
CS  
t2  
t6  
t4  
WR  
t10  
365 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
Figure 19-9 Motorola Bus Read Timing (BTS = 1)  
ADDR[12:0]  
DATA[7:0]  
R/W  
Address Valid  
Data Valid  
t5  
t1  
CS  
t2  
t3  
t4  
DS  
t10  
Figure 19-10 Motorola Bus Write Timing (BTS = 1)  
ADDR[12:0]  
DATA[7:0]  
R/W  
Address Valid  
t8  
t7  
t1  
CS  
t2  
t6  
t4  
DS  
t10  
366 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
19.6 JTAG Interface Timing  
Table 19-7 JTAG Interface Timing  
(VDD = 3.3V ±5%, TA = -40°C to +85°C.) (Figure 19-11)  
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
t1  
t2/t3  
t4  
t5  
t6  
1000  
500  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
JTCLK Clock Period  
50  
3
2
2
2
JTCLK Clock High/Low Time  
JTCLK to JTDI, JTMS Setup Time  
JTCLK to JTDI, JTMS Hold Time  
JTCLK to JTDO Delay  
JTCLK to JTDO High-Z Delay  
JTRST Width Low Time  
(Note 1)  
50  
50  
t7  
t8  
100  
Note 1: Clock can be stopped high or low.  
Figure 19-11 JTAG Interface Timing Diagram  
t1  
t2  
t3  
JTCLK  
t4  
t5  
JTDI, JTMS,  
JTRST  
t6  
t7  
JTD0  
t8  
JTRST  
367 of 368  
DS26556 4-Port Cell/Packet Over T1/E1/J1 Transceiver  
20 REVISION CHANGE HISTORY  
DATE  
DESCRIPTION  
012105  
New Product Release  
(Page 9) In Figure 1-1, removed ALE (nonexistent pin).  
090407  
(Page 54) Removed sentence referring to an original Figure 8-3 (nonexistent); updated Section 8  
figure numbers.  
368 of 368  
Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product.  
No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.  
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600  
© 2007 Maxim Integrated Products  
The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation.  

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BEL

DS2660-7EPD1T

DC-DC Regulated Power Supply Module, 2 Output, Hybrid, METAL, CASE S02, MODULE
BEL

DS2660-7EPD1TB1

DC-DC Regulated Power Supply Module, 2 Output, Hybrid, METAL, CASE S02, MODULE
BEL

DS2660-7EPD2

DC-DC Regulated Power Supply Module, 2 Output, Hybrid, METAL, CASE S02, MODULE
BEL