DS26503L [DALLAS]

T1/E1/J1 BITS Element; T1 / E1 / J1 BITS元
DS26503L
型号: DS26503L
厂家: DALLAS SEMICONDUCTOR    DALLAS SEMICONDUCTOR
描述:

T1/E1/J1 BITS Element
T1 / E1 / J1 BITS元

电信集成电路 PC
文件: 总123页 (文件大小:960K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
DS26503  
T1/E1/J1 BITS Element  
www.maxim-ic.com  
GENERAL DESCRIPTION  
FEATURES  
The DS26503 is a building-integrated timing-  
supply (BITS) clock-recovery element. The  
receiver portion can recover a clock from T1,  
E1, and 6312kHz synchronization timing  
interfaces. In T1 and E1 modes, the  
Synchronization Status Message (SSM) can also  
be recovered. The transmit portion can directly  
interface to T1 or E1 interfaces as well as source  
the SSM in T1 and E1 modes. The DS26503 can  
translate between any of the supported inbound  
synchronization clock rates to any supported  
outbound rate. A separate output is provided to  
source a 6312kHz clock. The device is  
controlled through a parallel, serial, or hardware  
controller port.  
CG.703 2048kHz Synchronization Interface  
Compliant  
CG.703 6312kHz Japanese Synchronization  
Interface Compliant  
CInterfaces to Standard T1/J1 (1.544MHz) and  
E1 (2.048MHz)  
CInterface to CMI-Coded T1/J1 and E1  
CShort- and Long-Haul Line Interface  
CTransmit and Receive T1 and E1 SSM  
Messages with Message Validation  
CCrystal-Less Jitter Attenuator with Bypass  
Mode  
CFully Independent Transmit and Receive  
Functionality  
CInternal Software-Selectable Receive- and  
Transmit-Side Termination for  
75/100/110/120Ω  
CMonitor Mode for Bridging Applications  
CAccepts 16.384MHz, 8.192MHz, 4.096MHz,  
2.048MHz, or 1.544MHz (T1 Only) Master  
Clock  
APPLICATIONS  
BITS Timing  
Rate Conversion  
Basic Transceiver  
C8-Bit Parallel Control Port, Multiplexed or  
Nonmultiplexed, Intel or Motorola  
CSerial (SPI) Control Port  
ORDERING INFORMATION  
CHardware Control Mode  
PART  
TEMP RANGE PIN-PACKAGE  
CProvides LOS, AIS, and LOF Indications  
Through Hardware Output Pins  
CFast Transmitter-Output Disable Through  
Device Pin for Protection Switching  
CIEEE 1149.1 JTAG Boundary Scan  
C3.3V Supply with 5V-Tolerant Inputs and  
Outputs  
DS26503L  
0°C to +70°C  
64 LQFP  
DS26503LN -40°C to +85°C 64 LQFP  
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.  
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DS26503 T1/E1/J1 BITS Element  
TABLE OF CONTENTS  
FEATURES.......................................................................................................................7  
1.  
1.1  
1.2  
1.3  
1.4  
1.5  
1.6  
GENERAL ........................................................................................................................7  
LINE INTERFACE...............................................................................................................7  
JITTER ATTENUATOR ........................................................................................................7  
FRAMER/FORMATTER .......................................................................................................8  
TEST AND DIAGNOSTICS ...................................................................................................8  
CONTROL PORT ...............................................................................................................8  
2.  
3.  
4.  
SPECIFICATIONS COMPLIANCE ...................................................................................9  
BLOCK DIAGRAMS.......................................................................................................12  
PIN FUNCTION DESCRIPTION .....................................................................................15  
4.1  
4.2  
4.3  
4.4  
4.5  
4.6  
4.7  
TRANSMIT PLL...............................................................................................................15  
TRANSMIT SIDE..............................................................................................................15  
RECEIVE SIDE................................................................................................................16  
CONTROLLER INTERFACE................................................................................................17  
JTAG ...........................................................................................................................21  
LINE INTERFACE.............................................................................................................21  
POWER .........................................................................................................................22  
5.  
6.  
PINOUT...........................................................................................................................23  
HARDWARE CONTROLLER INTERFACE....................................................................26  
6.1  
6.2  
6.3  
6.4  
6.5  
6.6  
6.7  
TRANSMIT CLOCK SOURCE .............................................................................................26  
INTERNAL TERMINATION..................................................................................................26  
LINE BUILD-OUT.............................................................................................................27  
RECEIVER OPERATING MODES........................................................................................27  
TRANSMITTER OPERATING MODES ..................................................................................28  
MCLK PRE-SCALER ......................................................................................................28  
OTHER HARDWARE CONTROLLER MODE FEATURES .........................................................29  
7.  
PROCESSOR INTERFACE............................................................................................30  
7.1  
7.2  
PARALLEL PORT FUNCTIONAL DESCRIPTION.....................................................................30  
SPI SERIAL PORT INTERFACE FUNCTIONAL DESCRIPTION .................................................30  
7.2.1 Clock Phase and Polarity ................................................................................................... 30  
7.2.2 Bit Order............................................................................................................................. 30  
7.2.3 Control Byte ....................................................................................................................... 30  
7.2.4 Burst Mode......................................................................................................................... 30  
7.2.5 Register Writes................................................................................................................... 31  
7.2.6 Register Reads .................................................................................................................. 31  
7.3  
REGISTER MAP ..............................................................................................................32  
7.3.1 Power-Up Sequence.......................................................................................................... 34  
7.3.2 Test Reset Register............................................................................................................ 34  
7.3.3 Mode Configuration Register.............................................................................................. 35  
7.4  
INTERRUPT HANDLING ....................................................................................................38  
STATUS REGISTERS .......................................................................................................38  
INFORMATION REGISTERS...............................................................................................39  
INTERRUPT INFORMATION REGISTERS..............................................................................39  
7.5  
7.6  
7.7  
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8.  
9.  
T1 FRAMER/FORMATTER CONTROL REGISTERS....................................................40  
T1 CONTROL REGISTERS ...............................................................................................40  
E1 FRAMER/FORMATTER CONTROL REGISTERS....................................................46  
8.1  
9.1  
9.2  
E1 CONTROL REGISTERS ...............................................................................................46  
E1 INFORMATION REGISTERS..........................................................................................48  
10.  
11.  
I/O PIN CONFIGURATION OPTIONS ............................................................................52  
T1 SYNCHRONIZATION STATUS MESSAGE ..............................................................55  
11.1 T1 BIT-ORIENTED CODE (BOC) CONTROLLER ................................................................55  
11.2 TRANSMIT BOC.............................................................................................................55  
11.3 RECEIVE BOC...............................................................................................................56  
12.  
E1 SYNCHRONIZATION STATUS MESSAGE..............................................................64  
12.1 SA/SI BIT ACCESS BASED ON CRC4 MULTIFRAME...........................................................64  
12.2 ALTERNATE SA/SI BIT ACCESS BASED ON DOUBLE-FRAME...............................................74  
13.  
LINE INTERFACE UNIT (LIU) ........................................................................................77  
13.1 LIU OPERATION ............................................................................................................78  
13.2 LIU RECEIVER ..............................................................................................................78  
13.2.1 Receive Level Indicator...................................................................................................... 78  
13.2.2 Receive G.703 Section 10 Synchronization Signal............................................................. 79  
13.2.3 Monitor Mode..................................................................................................................... 79  
13.3 LIU TRANSMITTER.........................................................................................................79  
13.3.1 Transmit Short-Circuit Detector/Limiter............................................................................... 80  
13.3.2 Transmit Open-Circuit Detector.......................................................................................... 80  
13.3.3 Transmit BPV Error Insertion.............................................................................................. 80  
13.3.4 Transmit G.703 Section 10 Synchronization Signal (E1 Mode) .......................................... 80  
13.4 MCLK PRE-SCALER......................................................................................................80  
13.5 JITTER ATTENUATOR......................................................................................................80  
13.6 CMI (CODE MARK INVERSION) OPTION...........................................................................81  
13.7 LIU CONTROL REGISTERS .............................................................................................82  
13.8 RECOMMENDED CIRCUITS ..............................................................................................90  
13.9 COMPONENT SPECIFICATIONS ........................................................................................92  
14.  
15.  
LOOPBACK CONFIGURATION.....................................................................................96  
6312KHZ SYNCHRONIZATION INTERFACE................................................................97  
15.1 RECEIVE 6312KHZ SYNCHRONIZATION INTERFACE OPERATION ........................................97  
15.2 TRANSMIT 6312KHZ SYNCHRONIZATION INTERFACE OPERATION.......................................97  
16.  
JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT...................98  
16.1 INSTRUCTION REGISTER...............................................................................................102  
16.2 TEST REGISTERS.........................................................................................................103  
16.3 BOUNDARY SCAN REGISTER.........................................................................................103  
16.4 BYPASS REGISTER ......................................................................................................103  
16.5 IDENTIFICATION REGISTER............................................................................................103  
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17.  
FUNCTIONAL TIMING DIAGRAMS.............................................................................106  
17.1 PROCESSOR INTERFACE ...............................................................................................106  
17.1.1 Parallel Port Mode............................................................................................................ 106  
17.1.2 SPI Serial Port Mode........................................................................................................ 106  
18.  
19.  
OPERATING PARAMETERS.......................................................................................109  
AC TIMING PARAMETERS AND DIAGRAMS ............................................................111  
19.1 MULTIPLEXED BUS.......................................................................................................111  
19.2 NONMULTIPLEXED BUS ................................................................................................114  
19.3 SERIAL BUS ................................................................................................................117  
19.4 RECEIVE SIDE AC CHARACTERISTICS ...........................................................................119  
19.5 TRANSMIT SIDE AC CHARACTERISTICS .........................................................................121  
20.  
21.  
REVISION HISTORY ....................................................................................................122  
PACKAGE INFORMATION..........................................................................................123  
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LIST OF FIGURES  
Figure 3-1. Block Diagram..................................................................................................................... 12  
Figure 3-2. Loopback Mux Diagram....................................................................................................... 13  
Figure 3-3. Transmit PLL Clock Mux Diagram ....................................................................................... 13  
Figure 3-4. Master Clock PLL Diagram.................................................................................................. 14  
Figure 13-1. Basic Network Connection................................................................................................. 77  
Figure 13-2. Typical Monitor Application................................................................................................ 79  
Figure 13-3. CMI Coding ....................................................................................................................... 81  
Figure 13-4. Basic Interface................................................................................................................... 90  
Figure 13-5. Protected Interface Using Internal Receive Termination.................................................... 91  
Figure 13-6. E1 Transmit Pulse Template ............................................................................................. 93  
Figure 13-7. T1 Transmit Pulse Template.............................................................................................. 93  
Figure 13-8. Jitter Tolerance (T1 Mode) ................................................................................................ 94  
Figure 13-9. Jitter Tolerance (E1 Mode) ................................................................................................ 94  
Figure 13-10. Jitter Attenuation (T1 Mode) ............................................................................................ 95  
Figure 13-11. Jitter Attenuation (E1 Mode)............................................................................................ 95  
Figure 16-1. JTAG Functional Block Diagram........................................................................................ 98  
Figure 16-2. TAP Controller State Diagram ......................................................................................... 101  
Figure 17-1. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 0............................................. 106  
Figure 17-2. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 0............................................. 106  
Figure 17-3. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 1............................................. 106  
Figure 17-4. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 1............................................. 107  
Figure 17-5. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 0 ............................................. 107  
Figure 17-6. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 0 ............................................. 107  
Figure 17-7. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 1 ............................................. 108  
Figure 17-8. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 1 ............................................. 108  
Figure 19-1. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 00)............................................................. 112  
Figure 19-2. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 00).............................................................. 112  
Figure 19-3. Motorola Bus Timing (BTS = 1 / BIS[1:0] = 00)................................................................ 113  
Figure 19-4. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 01).............................................................. 115  
Figure 19-5. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 01).............................................................. 115  
Figure 19-6. Motorola Bus Read Timing (BTS = 1 / BIS[1:0] = 01)....................................................... 116  
Figure 19-7. Motorola Bus Write Timing (BTS = 1 / BIS[1:0] = 01)....................................................... 116  
Figure 19-8. SPI Interface Timing Diagram, CPHA = 0, BIS[1:0] = 10 ................................................. 118  
Figure 19-9. SPI Interface Timing Diagram, CPHA = 1, BIS[1:0] = 10 ................................................. 118  
Figure 19-10. Receive Timing, T1/E1 .................................................................................................. 120  
Figure 19-11. Transmit Timing, T1/E1 ................................................................................................. 122  
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LIST OF TABLES  
Table 2-1. T1-Related Telecommunications Specifications...................................................................... 9  
Table 2-2. E1-Related Telecommunications Specifications ................................................................... 10  
Table 5-1. LQFP Pinout......................................................................................................................... 23  
Table 6-1. Transmit Clock Source ......................................................................................................... 26  
Table 6-2. Internal Termination.............................................................................................................. 26  
Table 6-3. E1 Line Build-Out ................................................................................................................. 27  
Table 6-4. T1 Line Build-Out.................................................................................................................. 27  
Table 6-5. Receive Path Operating Mode.............................................................................................. 27  
Table 6-6.Transmit Path Operating Mode.............................................................................................. 28  
Table 6-7. MCLK Pre-Scaler for T1 Mode.............................................................................................. 28  
Table 6-8. MCLK Pre-Scaler for E1 Mode ............................................................................................. 29  
Table 6-9. Other Operational Modes ..................................................................................................... 29  
Table 7-1. Port Mode Select.................................................................................................................. 30  
Table 7-2. Register Map Sorted By Address.......................................................................................... 32  
Table 8-1. T1 Alarm Criteria .................................................................................................................. 45  
Table 9-1. E1 Sync/Resync Criteria....................................................................................................... 47  
Table 9-2. E1 Alarm Criteria .................................................................................................................. 49  
Table 10-1. TS Pin Functions ................................................................................................................ 53  
Table 10-2. RLOF Pin Functions ........................................................................................................... 53  
Table 11-1. T1 SSM Messages ............................................................................................................. 55  
Table 12-1. E1 SSM Messages............................................................................................................. 64  
Table 13-1. Transformer Specifications ................................................................................................. 92  
Table 15-1. Specification of 6312kHz Clock Signal at Input Port........................................................... 97  
Table 15-2. Specification of 6312kHz Clock Signal at Output Port......................................................... 97  
Table 16-1. Instruction Codes for IEEE 1149.1 Architecture................................................................ 102  
Table 16-2. ID Code Structure............................................................................................................. 103  
Table 16-3. Device ID Codes............................................................................................................... 103  
Table 16-4. Boundary Scan Control Bits.............................................................................................. 104  
Table 18-1. Thermal Characteristics.................................................................................................... 109  
Table 18-2. Theta-JA () vs. Airflow.................................................................................................. 109  
JA  
Table 18-3. Recommended DC Operating Conditions......................................................................... 109  
Table 18-4. Capacitance ..................................................................................................................... 109  
Table 18-5. DC Characteristics............................................................................................................ 110  
Table 19-1. AC Characteristics, Multiplexed Parallel Port.................................................................... 111  
Table 19-2. AC Characteristics, Non-Mux Parallel Port ....................................................................... 114  
Table 19-3. AC Characteristics, Serial Bus.......................................................................................... 117  
Table 19-4. Receive Side AC Characteristics ...................................................................................... 119  
Table 19-5. Transmit Side AC Characteristics ..................................................................................... 121  
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1. FEATURES  
1.1 General  
Cꢀ64-pin, 10mm x 10mm LQFP package  
Cꢀ3.3V supply with 5V-tolerant inputs and outputs  
CꢀEvaluation kits  
CꢀIEEE 1149.1 JTAG Boundary Scan  
CꢀDriver source code available from the factory  
1.2 Line Interface  
CꢀRequires a single master clock (MCLK) for E1, T1, or J1 operation. Master clock can be  
2.048MHz, 4.096MHz, 8.192MHz, or 16.384MHz. Option to use 1.544MHz, 3.088MHz,  
6.176MHz, or 12.352MHz for T1-only operation.  
CꢀFully software configurable  
CꢀShort- and long-haul applications  
CꢀAutomatic receive sensitivity adjustments  
CꢀRanges include 0dB to -43dB or 0dB to -12dB for E1 applications; 0dB to -36dB or 0dB to -15dB  
for T1 applications  
CꢀReceive level indication in 2.5dB steps from -42.5dB to -2.5dB  
CꢀInternal receive termination option for 75, 100, 110, and 120lines  
CꢀMonitor application gain settings of 20dB, 26dB, and 32dB  
CꢀG.703 receive-synchronization signal mode  
CꢀFlexible transmit-waveform generation  
CꢀT1 DSX-1 line build-outs  
CꢀE1 waveforms include G.703 waveshapes for both 75coax and 120twisted cables  
CꢀAIS generation independent of loopbacks  
CꢀAlternating ones and zeros generation  
CꢀSquare-wave output  
CꢀOpen-drain output option  
CꢀTransmitter power-down  
CꢀTransmitter 50mA short-circuit limiter with exceeded indication of current limit  
CꢀTransmit open-circuit-detected indication  
1.3 Jitter Attenuator  
Cꢀ32-bit or 128-bit crystal-less jitter attenuator  
CꢀRequires only a 2.048MHz master clock for both E1 and T1 operation with the option to use  
1.544MHz for T1 operation  
CꢀCan be placed in either the receive or transmit path or disabled  
CꢀLimit trip indication  
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1.4 Framer/Formatter  
CꢀFull receive and transmit path transparency  
CꢀT1 framing formats include D4 and ESF  
CꢀE1 framing formats include FAS and CRC4  
CꢀDetailed alarm and status reporting with optional interrupt support  
CꢀRLOF, RLOS, and RAIS alarms interrupt on change of state  
CꢀJapanese J1 support includes:  
ꢀꢁ Ability to calculate and check CRC6 according to the Japanese standard  
ꢀꢁ Ability to generate yellow alarm according to the Japanese standard  
1.5 Test and Diagnostics  
Cꢀ Remote and Local Loopback  
1.6 Control Port  
Cꢀ8-bit parallel or serial control port  
CꢀMultiplexed or nonmultiplexed buses  
CꢀIntel or Motorola formats  
CꢀSupports polled or interrupt-driven environments  
CꢀSoftware access to device ID and silicon revision  
CꢀSoftware-reset supported with automatic clear on power-up  
CꢀHardware controller port  
CꢀHardware reset pin  
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2. SPECIFICATIONS COMPLIANCE  
The DS26503 meets all applicable sections of the relevant latest telecommunications specifications. The  
following table provides the T1 and E1 specifications and relevant sections that are applicable to the  
DS26503.  
Table 2-1. T1-Related Telecommunications Specifications  
ANSI T1.102- Digital Hierarchy Electrical Interface  
AMI Coding  
B8ZS Substitution Definition  
DS1 Electrical Interface. Line rate ±32ppm; Pulse Amplitude between 2.4V to 3.6V peak; power level  
between 12.6dBm to 17.9dBm; the T1 pulse mask is provided that we comply. DSX-1 for cross connects  
if the return loss is greater than -26dB. The DSX-1 cable is restricted up to 655 feet.  
This specification also provides cable characteristics of DSX-Cross Connect cable—22 AVG cables of  
1000 feet.  
ANSI T1.231- Digital Hierarchy- Layer 1 in Service Performance Monitoring  
BPV Error Definition; Excessive Zero Definition; LOS description; AIS definition  
ANSI T1.403- Network and Customer Installation Interface- DS1 Electrical Interface  
Description of the Measurement of the T1 Characteristics—100. Pulse shape and template compliance  
according to T1.102; power level 12.4dBm to 19.7dBm when all ones are transmitted.  
LBO for the Customer Interface (CI) is specified as 0dB, -7.5dB, and -15dB. Line rate is ±32ppm. Pulse  
Amplitude is 2.4 to 3.6V.  
AIS generation as unframed all ones is defined.  
The total cable attenuation is defined as 22dB. The DS26503 will function with up to -36dB cable loss.  
Note that the pulse template defined by T1.403 and T1.102 are different --- specifically at Times 0.61,  
-0.27, -34 and 0.77. The DS26524 is complaint to both templates.  
Pub 62411  
This specification has tighter jitter tolerance and transfer characteristics than other specifications.  
The jitter transfer characteristics are tighter than G.736 and Jitter Tolerance is tighter the G.823.  
(ANSI) “Digital Hierarchy – Electrical Interfaces”  
(ANSI) “Digital Hierarchy – Formats Specification”  
(ANSI) “Digital Hierarchy – Layer 1 In-Service Digital Transmission Performance Monitoring”  
(ANSI) “Network and Customer Installation Interfaces – DS1 Electrical Interface”  
(AT&T) “Requirements for Interfacing Digital Terminal Equipment to Services Employing the Extended  
Super frame Format”  
(AT&T) “High Capacity Digital Service Channel Interface Specification”  
(TTC) “Frame Structures on Primary and Secondary Hierarchical Digital Interfaces”  
(TTC) “ISDN Primary Rate User-Network Interface Layer 1 Specification”  
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Table 2-2. E1-Related Telecommunications Specifications  
ITUT G.703 Physical/Electrical Characteristics of G.703 Hierarchical Digital Interfaces  
Defines the 2048kbps bit rate—2048 ±50ppm; the transmission media are 75coax or 120twisted  
pair; peak-to-peak space voltage is ±0.237V; nominal pulse width is 244ns.  
Return loss 51Hz to 102Hz is 6dB; 102Hz to 3072Hz is 8dB; 2048Hz to 3072Hz is 14dB.  
Nominal peak voltage is 2.37V for coax and 3V for twisted pair.  
The pulse template for E1 is defined in G.703.  
ITUT G.736 Characteristics of Synchronous Digital Multiplex Equipment operating at 2048kbps  
The peak-to-peak jitter at 2048kbps has to be less than 0.05 UI at 20Hz to 100Hz.  
Jitter transfer between 2.048 synchronization signal and 2.048 transmission signal is provided.  
ITUT G.742 Second-Order Digital Multiplex Equipment Operating at 8448kbps  
The DS26503 jitter attenuator is complaint with Jitter transfer curve for sinusoidal jitter input.  
ITUT G.772  
This specification provides the method for using receiver for transceiver 0 as a monitor for the remainder  
of the seven transmitter/receiver combinations.  
ITUT G.775  
A LOS detection criterion is defined.  
ITUT G.823 The control of jitter and wander within digital networks, which are based on 2.048kbps  
hierarchy  
G.823 provides the jitter amplitude tolerance at different frequencies, specifically 20Hz, 2.4kHz, 18kHz,  
and 100kHz.  
ETSI 300 233  
This specification provides LOS and AIS signal criteria for E1 mode.  
Pub 62411  
This specification has tighter jitter tolerance and transfer characteristics than other specifications.  
The jitter transfer characteristics are tighter than G.736 and jitter tolerance is tighter then G.823.  
(ITU) “Synchronous Frame Structures used at 1544, 6312k, 2048, 8488, and 44,736kbps Hierarchical  
Levels”  
(ITU) “Frame Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to Basic Frame  
Structures Defined in Recommendation G.704”  
(ITU) “Characteristics of primary PCM Multiplex Equipment Operating at 2048kbps”  
(ITU) Characteristics of a synchronous digital multiplex equipment operating at 2048kbps”  
(ITU) “Loss Of Signal (LOS) and Alarm Indication Signal (AIS) Defect Detection and Clearance  
Criteria”  
(ITU) “The Control of Jitter and Wander Within Digital Networks Which are Based on the 2048kbps  
Hierarchy”  
(ITU) “Primary Rate User-Network Interface – Layer 1 Specification”  
(ITU) “Error Performance Measuring Equipment Operating at the Primary Rate and Above”  
(ITU) “In-service code violation monitors for digital systems”  
(ETSI) “Integrated Services Digital Network (ISDN); Primary rate User-Network Interface (UNI); Part  
1/ Layer 1 specification”  
(ETSI) “Transmission and multiplexing; Physical/electrical characteristics of hierarchical digital  
interfaces for equipment using the 2048kbps-based plesiochronous or synchronous digital hierarchies”  
(ETSI) “Integrated Services Digital Network (ISDN); Access digital section for ISDN primary rate”  
(ETSI) “Integrated Services Digital Network (ISDN); Attachment requirements for terminal equipment  
to connect to an ISDN using ISDN primary rate access”  
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Table 2-3. E1-Related Telecommunications Specifications (continued)  
(ETSI) “Business Telecommunications (BT); Open Network Provision (ONP) technical requirements;  
2048lkbps digital unstructured leased lines (D2048U) attachment requirements for terminal equipment  
interface”  
(ETSI) “Business Telecommunications (BTC); 2048kbps digital structured leased lines (D2048S);  
Attachment requirements for terminal equipment interface”  
(ITU) “Synchronous Frame Structures used at 1544, 6312, 2048, 8488, and 44,736kbps Hierarchical  
Levels”  
(ITU) “Frame Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to Basic Frame  
Structures Defined in Recommendation G.704”  
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3. BLOCK DIAGRAMS  
Figure 3-1. Block Diagram  
MCLK  
DS26503  
JA CLOCK  
RCLK  
MASTER CLOCK  
CLOCK  
RTIP  
LOF_CCE  
R
E
M
O
T
L
JA  
RX  
+ DATA  
ENABLED  
AND IN RX  
PATH  
O
C
A
L
LIU  
- DATA  
RRING  
RLOS  
RAIS  
RSER  
T1/E1 SSM  
FRAMER  
RS  
E
L
O
O
P
JITTER  
ATTENUATOR  
CAN BE  
L
PLL  
O
O
P
B
A
C
K
ASSIGNED TO  
RECEIVE OR  
TRANSMIT PATH  
OR DISABLED  
CLOCK  
MUX  
TCLK  
B
A
C
K
PLL_OUT  
TX CLOCK  
TTIP  
TSER  
M
U
X
JA  
TX  
LIU  
T1/E1 SSM  
+ DATA  
- DATA  
ENABLED  
AND IN TX  
PATH  
M
U
X
FORMATTER  
TS  
PARALLEL/SERIAL CPU I/F  
HARDWARE CONTROLLER  
TSTRST  
JTAGPORT  
JTMS JTRST JTCLK JTDI JTDO  
BIS1 BIS0  
PARALLEL,  
SERIAL, OR  
HARDWARE  
CONTROLLER  
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DS26503 T1/E1/J1 BITS Element  
Figure 3-2. Loopback Mux Diagram  
CLOCK  
RCLK  
JITTER  
FROM RX  
+ DATA  
- DATA  
ATTENUATOR  
ENABLED AND  
IN RX PATH  
TO RX  
+ DATA  
LIU  
FRAMER  
- DATA  
LOCAL  
LOOPBACK  
(LBCR.3)  
TX CLOCK  
CLOCK  
+ DATA  
- DATA  
JITTER  
FROM TX  
ATTENUATOR  
ENABLED AND  
IN TX PATH  
+ DATA  
TO TX  
LIU  
FORMATTER  
- DATA  
REMOTE  
LOOPBACK  
(LBCR.4)  
Figure 3-3. Transmit PLL Clock Mux Diagram  
TPCR.3  
TPCR.4  
TPCR.6  
TPCR.7  
TPCR.5  
TPCR.2  
IN  
SEL  
OUT  
SEL  
PLL_OUT PIN  
RECOVERED CLOCK  
TCLK PIN  
TX PLL  
OUTPUT = 1.544MHz,  
2.048MHz, 6.312MHz  
TX CLOCK  
JA CLOCK  
TPCR.0  
(TCSS0)  
TPCR.1  
(TCSS1)  
(HARDWARE MODE PIN NAME)  
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DS26503 T1/E1/J1 BITS Element  
Figure 3-4. Master Clock PLL Diagram  
MCLK PIN  
LIC4.6  
PRE-SCALER  
(MPS0)  
LIC4.7  
(MPS1)  
DIVIDE BY 1, 2, 4,  
OR 8  
X12,X16  
MULTIPLIER  
PLL  
JA CLOCK  
2.048MHz to  
1.544MHz PLL  
LIC2.3  
(JACKS)  
TO CLOCK AND DATA  
RECOVERY ENGINE IN  
RECEIVE LIU  
(HARDWARE MODE PIN NAME)  
14 of 123  
DS26503 T1/E1/J1 BITS Element  
4. PIN FUNCTION DESCRIPTION  
4.1 Transmit PLL  
NAME  
TYPE  
FUNCTION  
Transmit PLL Output. 1544kHz, 2048kHz, 64kHz, or 6312kHz output from  
the internal TX PLL.  
Transmit Clock Input. A 64kHz, 1.544MHz, 2.048MHz, or 6312kHz  
primary clock. May be selected by the TX PLL mux to provide a clock to the  
transmit section.  
PLL_OUT  
O
TCLK  
I
4.2 Transmit Side  
NAME  
TYPE  
FUNCTION  
Transmit Serial Data. Source of transmit data sampled on the falling edge of  
the selected transmit clock.  
TSER  
I
TSYNC. When in “input” mode, a pulse at this pin will establish either frame  
or multiframe boundaries for the transmit side. In output mode, the pin can be  
programmed to output a frame or multiframe sync pulse useful for aligning  
data.  
TS  
I/O  
O
Transmit Clock Output. Buffered clock that is used to clock data through the  
transmit-side formatter (i.e., either TCLK or RCLK).  
TCLKO  
TPOSO  
Transmit Positive-Data Output. In T1 or E1 mode, updated on the rising  
edge of TCLKO with the bipolar data out of the transmit-side formatter. Can  
be programmed to source NRZ data via the output-data format (IOCR1.0)  
control bit. In 6312 mode, this pin is low.  
Transmit Negative-Data Output. In T1 or E1 mode, updated on the rising  
edge of TCLKO with the bipolar data out of the transmit-side formatter. In  
6312 mode, this pin is low.  
O
TNEGO  
O
15 of 123  
DS26503 T1/E1/J1 BITS Element  
4.3 Receive Side  
NAME  
TYPE  
FUNCTION  
Receive Clock. Recovered 1.544MHz (T1), 2.048MHz (E1), or 6312 kHz  
RCLK  
O
(G.703 Synchronization Interface).  
Receive Sync  
T1/E1 Mode: An extracted pulse, one RCLK wide, is output at this pin that  
identifies either frame (IOCR1.5 = 0) or multiframe (IOCR1.5 = 1)  
boundaries. If set to output frame boundaries, then through IOCR1.6, RS can  
also be set to output double-wide pulses on signaling frames in T1 mode.  
RS  
O
O
O
6312K Mode: This pin will be in a high-impedance state.  
Receive Serial Data  
T1/E1 Mode: This is the received NRZ serial data updated on rising edges of  
RSER  
RLOF  
RCLK.  
6312K Mode: This pin will be in a high-impedance state.  
Receive Loss Of Frame. This output can be configured to be a Loss Of  
Transmit Clock indicator via IOCR.4 when operating in T1 or E1 mode.  
T1/E1 Mode: Set when the receive synchronizer is searching for frame  
alignment (RLOF mode), or set when the signal at the TCLK pin has not  
transitioned for approximately 15 periods of the scaled MCLK (LOTC mode).  
6312K Mode: This pin will be in a high-impedance state.  
Receive Loss Of Signal  
T1 Mode: High when 192 consecutive zeros detected.  
E1 Mode: High when 255 consecutive zeros detected.  
6312K Mode: High when consecutive zeros detected for 65s typically.  
Receive Alarm Indication Signal  
T1 Mode: Will toggle high when receive Blue Alarm is detected.  
E1 Mode: Will toggle high when receive AIS is detected.  
6312K Mode: This pin will be in a high-impedance state.  
RLOS  
RAIS  
O
O
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DS26503 T1/E1/J1 BITS Element  
4.4 Controller Interface  
NAME  
TYPE  
FUNCTION  
Interrupt/JA Clock Source Select 1  
INT: Flags host controller during events, alarms, and conditions defined in  
the status registers. Active-low open-drain output.  
INT/  
I/O  
JACKS  
JACKS: Hardware Mode: JA Clock Select. Set this pin high for T1 mode  
operation when either a 2.048MHz, 4.096MHz, 8.192MHz or 16.382MHz  
signal is applied at MCLK.  
Transmit Mode Select 1. In Hardware Mode (BIS[1:0] = 11), this bit is used  
to configure the transmit operating mode.  
Transmit Mode Select 2. In Hardware Mode (BIS[1:0] = 11), this bit is used  
to configure the transmit operating mode.  
TMODE1  
TMODE2  
I
I
Tri-State Control and Device Reset. A dual-function pin. A zero-to-one  
transition issues a hardware reset to the DS26503 register set. Configuration  
register contents are set to the default state. Leaving TSTRST high tri-states  
all output and I/O pins (including the parallel control port). Set low for  
normal operation. Useful for in-board level testing.  
Processor Interface Mode Select 1, 0. These bits select the processor  
interface mode of operation.  
TSTRST  
I
BIS[1:0]  
I
BIS[1:0] : 00 = Parallel Port Mode (Multiplexed)  
01 = Parallel Port Mode (Nonmultiplexed)  
10 = Serial Port Mode  
11 = Hardware Mode  
Data Bus D[7] or Address/Data Bus AD[7]/Transmit Termination Select  
A[7]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[7].  
AD[7]/  
RITD  
I/O  
I/O  
AD[7]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[7].  
RITD: In Hardware Mode (BIS[1:0] = 11), it disables the internal receive  
termination.  
Data Bus D[6] or Address/Data Bus AD[6]/Transmit Termination Select  
A[6]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[6].  
AD[6]/  
TITD  
AD[6]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[6].  
TITD: In Hardware Mode (BIS[1:0] = 11), it disables the internal transmit  
termination.  
Data Bus D[5] or Address/Data Bus AD[5]/Receive Framing Mode Select  
Bit 1  
A[5]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[5].  
AD[5]/  
I/O  
RMODE1  
AD[5]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[5].  
RMODE1: In Hardware Mode (BIS[1:0] = 11), it selects the receive side  
operating mode.  
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DS26503 T1/E1/J1 BITS Element  
NAME  
TYPE  
FUNCTION  
Data Bus D[4] or Address/Data Bus AD[4]/Receive Framing Mode Select  
Bit 0  
A[4]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[4].  
AD[4]/  
I/O  
RMODE0  
AD[4]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[4].  
RMODE0: In Hardware Mode (BIS[1:0] = 11), it selects the receive side  
operating mode.  
Data Bus D[3] or Address/Data Bus AD[3]/TS Mode Select  
A[3]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[3].  
AD[3]/TSM  
I/O  
I/O  
AD[3]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[3].  
TSM: In Hardware Mode (BIS[1:0] = 11), this pin selects the function of TS.  
Please see the register descriptions for more detailed information.  
Data Bus D[2] or Address/Data Bus AD[2]/RS Mode Select/Serial Port  
Clock  
A[2]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[2].  
AD[2]/RSM/  
SCLK  
AD[2]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[2].  
RSM: In Hardware Mode (BIS[1:0] = 11), this pin selects the function of RS.  
Please see the register descriptions for more detailed information.  
SCLK: In Serial Port mode this is the serial clock input.  
Data Bus D[1] or Address/Data Bus AD[1]/Receive Mode Select 3/Master  
Out-Slave In  
A[1]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[1].  
AD[1]/  
RMODE3/  
MOSI  
AD[1]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[1].  
I/O  
RMODE3: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive  
side operating mode.  
MOSI: Serial data input called Master Out-Slave In for clarity of data transfer  
direction.  
Data Bus D[0] or Address/Data Bus AD[0]/Transmit Clock Source Select  
0/Master In-Slave Out  
A[0]: In nonmultiplexed bus operation (BIS[1:0] = 01), it serves as the data  
bus D[0].  
AD[0]/  
TCSS0/  
MISO  
I/O  
I
AD[0]: In multiplexed bus operation (BIS[1:0] = 00), it serves as the  
multiplexed address/data bus AD[0].  
TCSS0: Transmit Clock Source Select 0.  
MISO: In serial bus mode (BIS[1:0] = 10), this pin serves as the serial data  
output Master In-Slave Out.  
TCSS1  
Transmit Clock Source Select. Transmit Clock Source Select 1  
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DS26503 T1/E1/J1 BITS Element  
NAME  
TYPE  
FUNCTION  
Address Bus Bit A[6]/MCLK Prescale Select  
A6: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[6].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A6/MPS0  
I
MPS0: In Hardware Mode (BIS[1:0] = 11), MCLK prescale select is used to  
set the prescale value for the PLL.  
Address Bus Bit A[5]/Serial Port Clock Polarity Select/Transmit Mode  
Select 0  
A5: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[5].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A5/CPOL/  
TMODE0  
I
I
CPOL: In Serial Port Mode (BIS[1:0] = 10), this pin selects the serial port  
clock polarity. Please see the functional timing diagrams for the Serial Port  
Interface for more information.  
TMODE0: In Hardware Mode (BIS[1:0] = 11), this pin is used to configure  
the transmit operating mode.  
Address Bus Bit A[4]/Serial Port Clock Phase Select/Line Build-Out  
Select 2  
A4: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[4].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A4/CPHA/  
L2  
CPHA: In Serial Port Mode (BIS[1:0] = 10), this pin selects the serial port  
clock phase. Please see the functional timing diagrams for the Serial Port  
Interface for more information.  
L2: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out  
value.  
Address Bus Bit A[3]/Line Build-Out Select 1  
A3: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[3].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A3/L1  
I
I
I
L1: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out  
value.  
Address Bus Bit A[2]/Line Build-Out Select 0  
A2: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[2].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A2/L0  
L0: In Hardware Mode (BIS[1:0] = 11), this pin selects the line build-out  
value.  
Address Bus Bit A[1]/Transmit AIS  
A1: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[1].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A1/TAIS  
TAIS: When set to a 1 and in T1/E1 operating modes, the transmitter will  
transmit an AIS pattern. This pin is ignored in all other operating modes.  
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DS26503 T1/E1/J1 BITS Element  
NAME  
TYPE  
FUNCTION  
Address Bus Bit A[0]/E1 Termination Select  
A0: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[0].  
In multiplexed bus operation (BIS[1:0] = 00), these pins are not used and  
should be tied low.  
A0/E1TS  
I
E1TS: In Hardware Mode (BIS[1:0] = 11), selects the E1 internal termination  
value (0 = 120, 1 = 75).  
Bus Type Select/Transmit and Receive B8ZS/HDB3 Enable  
BTS: Strap high to select Motorola bus timing; strap low to select Intel bus  
timing. This pin controls the function of the RD (DS), ALE (AS), and WR  
(R/W) pins. If BTS = 1, then these pins assume the function listed in  
parentheses ().  
BTS/HBE  
I
HBE: In Hardware Mode (BIS[1:0] = 11), this pin enables transmit and  
receive B8ZS/HDB3 when in T1/E1 operating modes.  
Read Input-Data Strobe/Receive Mode Select Bit 2  
RD (DS): These pins are active-low signals. DS is active high when BIS[1:0]  
= 01. See the bus timing diagrams.  
RD(DS)/  
I
I
RMODE2  
RMODE2: In Hardware Mode (BIS[1:0] = 11), this pin selects the receive  
side operating mode.  
Chip Select/Remote Loopback Enable  
CS: This active-low signal must be low to read or write to the device. This  
signal is used for both the parallel port and the serial port modes.  
RLB: In Hardware Mode (BIS[1:0] = 11), when high, remote loopback is  
enabled. This function is only valid when the transmit side and receive side  
are in the same operating mode.  
CS/RLB  
Address Latch Enable (Address Strobe)/Address Bus Bit 7/MCLK  
Prescale Select 1  
ALE (AS): In multiplexed bus operation (BIS[1:0] = 00), it serves to  
demultiplex the bus on a positive-going edge.  
ALE (AS)/  
A7/MPS1  
I
I
A7: In nonmultiplexed bus operation (BIS[1:0] = 01), this pin serves as A[7].  
MPS1: In Hardware Mode (BIS[1:0] = 11), MCLK prescale select, used to set  
the prescale value for the PLL.  
Write Input (Read/Write)/Transmit Mode Select 3  
WR: In Processor Mode, this pin is the active-low write signal.  
TMODE3: In Hardware Mode, this pin selects the transmit-side operating  
mode.  
WR (R/W)/  
TMODE3  
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DS26503 T1/E1/J1 BITS Element  
4.5 JTAG  
NAME  
TYPE  
FUNCTION  
JTAG Clock. This clock input is typically a low frequency (less than 10MHz)  
50% duty cycle clock signal.  
JTCLK  
I
JTAG Mode Select (with Pullup). 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). 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.  
JTMS  
I
I
JTDI  
JTAG Data Output. 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  
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.  
JTDO  
O
I
JTRST  
4.6 Line Interface  
NAME  
TYPE  
FUNCTION  
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 DS26503 in T1-only operation, a 1.544MHz (50ppm) clock source  
can be used.  
MCLK  
I
Receive Tip. Analog input for clock recovery circuitry. This pin connects via a  
1:1 transformer to the network. See the Line Interface Unit section for details.  
Receive Ring. Analog input for clock recovery circuitry. This pin connects via  
a 1:1 transformer to the network. See the Line Interface Unit section for details.  
Transmit Tip. Analog line-driver output. This pin connects via a 1:2 step-up  
transformer to the network. See the Line Interface Unit section for details.  
Transmit Ring. Analog line-driver output. This pin connects via a 1:2 step-up  
transformer to the network. See the Line Interface Unit section for details.  
Transmit High-Impedance Enable. When high, TTIP and TRING will be  
placed into a high-impedance state.  
RTIP  
RRING  
TTIP  
I
I
O
O
I
TRING  
THZE  
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DS26503 T1/E1/J1 BITS Element  
4.7 Power  
NAME  
TYPE  
FUNCTION  
Digital Positive Supply. 3.3V ±5%. Should be tied to the RVDD and TVDD  
DVDD  
RVDD  
TVDD  
DVSS  
RVSS  
TVSS  
pins.  
Receive Analog Positive Supply. 3.3V ±5%. Should be tied to the DVDD and  
TVDD pins.  
Transmit Analog Positive Supply. 3.3V ±5%. Should be tied to the DVDD  
and RVDD pins.  
Digital Signal Ground. 0.0V. Should be tied to the RVSS and TVSS pins.  
Receive Analog Signal Ground. 0.0V. Should be tied to the DVSS and TVSS  
pins.  
Transmit Analog Signal Ground. 0.0V. Should be tied to the DVSS and  
RVSS pins.  
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DS26503 T1/E1/J1 BITS Element  
5. PINOUT  
Table 5-1. LQFP Pinout  
MODE  
SERIAL  
PORT  
PIN  
TYPE  
FUNCTION  
PARALLEL  
PORT  
HARDWARE  
Parallel Port Mode: Address/Data Bus Bit 2  
1
I/O  
AD2  
AD3  
AD4  
AD5  
AD6  
AD7  
SCLK  
RSM  
Serial Port Mode: Serial Clock  
Hardware Mode: RS Mode Select  
Parallel Port Mode: Address/Data Bus Bit 3  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: TS Mode Select  
2
I/O  
TSM  
RMODE0  
RMODE1  
TITD  
Parallel Port Mode: Address/Data Bus Bit 4  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Receive Mode Select 0  
Parallel Port Mode: Address/Data Bus Bit 5  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Receive Mode Select 1  
Parallel Port Mode: Address/Data Bus Bit 6  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit Internal Termination Disable  
Parallel Port Mode: Address/Data Bus Bit 7  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Receive Internal Termination Disable  
3
I/O  
4
I/O  
5
I/O  
6
I/O  
RITD  
7, 24,  
58  
I
I
DVDD  
DVSS  
DVDD  
DVSS  
DVDD  
DVSS  
Digital Positive Supply  
8, 22,  
56  
Digital Signal Ground  
Parallel Port Mode: Address Bus Bit 0  
9
I
I
I
I
I
I
I
A0  
A1  
A2  
A3  
A4  
A5  
A6  
E1TS  
TAIS  
L0  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: E1 Internal Termination Select  
Parallel Port Mode: Address Bus Bit 1  
10  
11  
12  
13  
14  
15  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit AIS  
Parallel Port Mode: Address Bus Bit 2  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Line Build-Out Select 0  
Parallel Port Mode: Address Bus Bit 3  
L1  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Line Build-Out Select 1  
Parallel Port Mode: Address Bus Bit 4  
CPHA  
CPOL  
L2  
Serial Port Mode: Serial Port Clock Phase Select  
Hardware Mode: Line Build-Out Select 2  
Parallel Port Mode: Address Bus Bit 5  
TMODE0  
MPS0  
Serial Port Mode: Serial Port Clock Polarity Select  
Hardware Mode: Transmit Mode Select 0  
Parallel Port Mode: Address Bus Bit 6  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: MCLK Prescaler Select 0  
Parallel Port Mode: Address Latch Enable/Address Bus  
Bit 7  
16  
I
ALE (AS)/A7  
MPS1  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: MCLK Prescaler Select 1  
23 of 123  
DS26503 T1/E1/J1 BITS Element  
MODE  
SERIAL  
PORT  
TCLK  
TCLKO  
TNEGO  
TPOSO  
TSER  
TS  
PIN  
TYPE  
FUNCTION  
PARALLEL  
PORT  
TCLK  
TCLKO  
TNEGO  
TPOSO  
TSER  
TS  
HARDWARE  
17  
18  
19  
20  
21  
23  
25  
26  
27  
28  
29  
30  
I
O
O
O
I
I/O  
O
O
O
O
O
TCLK  
TCLKO  
TNEGO  
TPOSO  
TSER  
TS  
RCLK  
RS  
N.C.  
External Transmit Clock Input  
Transmit Clock Output  
Transmit Negative-Data Output  
Transmit Positive-Data Output  
Transmit Serial Data  
T1/E1 Mode: Transmit Frame/Multiframe Sync  
Receive Clock  
RCLK  
RS  
RCLK  
RS  
T1/E1 Mode: Receive Frame/Multiframe Boundary  
No Connect. This pin must be left open.  
Receive Serial Data  
N.C.  
N.C.  
RSER  
RAIS  
RSER  
RAIS  
RSER  
RAIS  
RLOF  
Receive Alarm Indication Signal  
Receive Loss of Frame  
RLOF  
RLOF  
Parallel Port Mode: Unused, should be connected to  
VSS.  
31  
I
TCSS1  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit Clock Source Select 1  
Receive Loss Of Signal  
32  
33  
O
I
RLOS  
JTMS  
JTCLK  
JTRST  
JTDI  
JTDO  
RVDD  
TSTRST  
RLOS  
JTMS  
JTCLK  
JTRST  
JTDI  
JTDO  
RVDD  
TSTRST  
RLOS  
JTMS  
JTCLK  
JTRST  
JTDI  
JTDO  
RVDD  
TSTRST  
IEEE 1149.1 Test Mode Select  
IEEE 1149.1 Test Clock Signal  
IEEE 1149.1 Test Reset  
IEEE 1149.1 Test Data Input  
IEEE 1149.1 Test Data Output  
Receive Analog Positive Supply  
Test/Reset  
34  
I
35  
I
36  
I
37  
O
I
38  
39  
I
40,  
43, 45  
41  
I
RVSS  
RVSS  
RVSS  
Receive Analog Signal Ground  
I
I
I
RTIP  
RRING  
MCLK  
RTIP  
RRING  
MCLK  
RTIP  
RRING  
MCLK  
Receive Analog Tip Input  
42  
Receive Analog Ring Input  
44  
Master Clock Input  
Parallel Port Mode: Interrupt  
46  
47  
I/O  
O
INT  
INT  
JACKS  
Serial Port Mode: Interrupt  
Hardware Mode: Jitter Attenuator clock select  
Transmit PLL (TX PLL) Clock Output  
Parallel Port Mode: Unused, should be connected to  
VSS.  
PLL_OUT  
PLL_OUT  
PLL_OUT  
48  
I
TMODE2  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit Mode Select 2  
Parallel Port Mode: Unused, should be connected to  
VSS.  
49  
I
TMODE1  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit Mode Select 1  
Transmit High-Impedance Enable  
Transmit Analog Tip Output  
50  
51  
52  
53  
54  
I
O
I
I
O
THZE  
TTIP  
TVSS  
TVDD  
TRING  
THZE  
TTIP  
TVSS  
TVDD  
TRING  
THZE  
TTIP  
TVSS  
TVDD  
TRING  
Transmit Analog Signal Ground  
Transmit Analog Positive Supply  
Transmit Analog Ring Output  
Parallel Port Mode: Bus Type Select (Motorola/Intel)  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Receive and Transmit DB3/B8ZS  
Enable  
55  
I
BTS  
HBE  
57  
59  
I
I
BIS0  
BIS1  
BIS0  
BIS1  
BIS0  
BIS1  
Bus Interface Select Mode 0  
Bus Interface Select Mode 1  
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DS26503 T1/E1/J1 BITS Element  
MODE  
SERIAL  
PORT  
PIN  
TYPE  
FUNCTION  
PARALLEL  
PORT  
HARDWARE  
Parallel Port Mode: Chip Select (Active Low)  
Serial Port Mode: Chip Select (Active Low)  
Hardware Mode: Remote Loopback Enable  
Parallel Port Mode: Read Input (Data Strobe), Active  
Low.  
60  
I
CS  
CS  
RLB  
61  
62  
I
I
RD (DS)  
RMODE2  
TMODE3  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Receive Mode Select 2  
Parallel Port Mode: Write Input (Read/Write), Active  
Low  
WR (R/W)  
Serial Port Mode: Unused, should be connected to VSS.  
Hardware Mode: Transmit Mode Select 3  
Parallel Port Mode: Address/Data Bus Bit 0  
Serial Port Mode: Serial Data Out (Master In-Slave  
Out)  
63  
64  
I/O  
I/O  
AD0  
AD1  
MIS0  
MOSI  
TCSS0  
Hardware Mode: Transmit Clock Source Select 0  
Parallel Port Mode: Address/Data Bus Bit 1  
Serial Port Mode: Serial Data In (Master Out-Slave In)  
Hardware Mode: Receive Mode Select 3  
RMODE3  
25 of 123  
DS26503 T1/E1/J1 BITS Element  
6. HARDWARE CONTROLLER INTERFACE  
In Hardware Controller mode, the parallel and serial port pins are reconfigured to provide direct access to  
certain functions in the port. Only a subset of the device’s functionality is available in hardware mode.  
Each register description throughout the data sheet indicates the functions that may be controlled in  
hardware mode and several alarm indicators that are available in both hardware and processor mode.  
Also indicated are the fixed states of the functions not controllable in hardware mode.  
6.1 Transmit Clock Source  
Refer to Figure 3-3. In Hardware Controller mode, the input to the TX PLL is always TCLK PIN. TX  
CLOCK is selected by the TCSS0 and TCSS1 pins, as shown in Table 6-1. The PLL_OUT pin is always  
the same signal as select for TX CLOCK. If the user wants to slave the transmitter to the recovered  
clock, then the RCLK pin must be tied to the TCLK pin externally.  
Table 6-1. Transmit Clock Source  
TCSS1  
TCSS0  
TRANSMIT CLOCK SOURCE  
The TCLK pin is the source of transmit clock.  
The PLL_CLK is the source of transmit clock.  
PIN 31  
PIN 63  
0
0
1
1
0
1
0
1
The scaled signal present at MCLK as the transmit  
clock.  
The signal present at RCLK is the transmit clock.  
6.2 Internal Termination  
In Hardware Controller mode, the internal termination is automatically set according to the receive or  
transmit mode selected. It can be disabled via the TITD and RITD pins. If internal termination is enabled  
in E1 mode, the E1TS pin is use to select 75or 120termination. The E1TS pin applies to both  
transmit and receive.  
Table 6-2. Internal Termination  
PIN NAME  
FUNCTION  
Transmit Internal Termination Disable. Disables the internal transmit  
termination. The internal transmit termination value is dependent on the state of  
the TMODEx pins.  
Receive Internal Termination Disable. Disables the internal receive  
termination. The internal receive termination value is dependent on the state of  
the RMODEx pins.  
TITD  
PIN 5  
RITD  
PIN 6  
E1 Termination Select. Selects 120or 75internal termination when one of  
the E1 modes is selected and internal termination is enabled. IF E1 is selected for  
both transmit and receive, then both terminations will be the same.  
0 = 75ꢂ  
E1TS  
PIN 9  
1 = 120ꢂ  
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DS26503 T1/E1/J1 BITS Element  
6.3 Line Build-Out  
Table 6-3. E1 Line Build-Out  
L2  
L1  
L0  
APPLICATION  
N (1)  
RETURN LOSS  
Rt (1)  
PIN 13 PIN 12 PIN 11  
0
0
1
1
1
1
0
0
0
0
1
1
0
1
0
1
0
1
75normal  
120normal  
1:2  
1:2  
1:2  
1:2  
N.M.  
N.M.  
21dB  
21dB  
0
0
75with high return loss*  
120with high return loss*  
Reserved  
6.2Ω  
11.6Ω  
Reserved  
*TTD pin must be connected high in this mode.  
N.M. = not meaningful  
Table 6-4. T1 Line Build-Out  
L2  
L1  
L0  
RETURN  
APPLICATION  
N (1)  
Rt (1)  
PIN 13 PIN 12  
PIN 11  
LOSS  
N.M.  
N.M.  
N.M.  
N.M.  
N.M.  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
DSX-1 (0 to 133 feet)/0dB CSU  
DSX-1 (133 to 266 feet)  
DSX-1 (266 to 399 feet)  
DSX-1 (399 to 533 feet)  
DSX-1 (533 to 655 feet)  
Reserved  
1:2  
1:2  
1:2  
1:2  
1:2  
0
0
0
0
0
Reserved  
Reserved  
6.4 Receiver Operating Modes  
Table 6-5. Receive Path Operating Mode  
RMODE3 RMODE2 RMODE1 RMODE0  
RECEIVE PATH OPERATING MODE  
PIN 64  
PIN 61  
PIN 4  
PIN 3  
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
T1 D4  
T1 ESF  
J1 D4  
J1 ESF  
E1 FAS  
E1 CAS  
E1 CRC4  
E1 CAS and CRC4  
E1 G.703 2048kHz Synchronization Interface  
Reserved  
Reserved  
6312kHz Synchronization Interface  
Reserved  
Reserved  
Reserved  
Reserved  
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DS26503 T1/E1/J1 BITS Element  
6.5 Transmitter Operating Modes  
Table 6-6.Transmit Path Operating Mode  
TMODE3 TMODE2 TMODE1 TMODE0  
TRANSMIT PATH OPERATING MODE  
PIN 62  
PIN 48  
PIN 49  
PIN 14  
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
0
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
0
1
0
0
1
0
1
0
1
0
1
0
1
T1 D4  
T1 ESF  
J1 D4  
J1 ESF  
E1 FAS  
E1 FAS + CAS (Note 1)  
Reserved  
E1 CRC4  
E1 CRC4 + CAS (Note 1)  
Reserved  
E1 G.703 2048kHz Synchronization Interface  
Reserved  
Reserved  
6312kHz Synchronization Interface (Note 2)  
Reserved  
Reserved  
Reserved  
Reserved  
The DS26503 does not have an internal source for CAS signaling and multiframe alignment generation. CAS  
signaling, and the multiframe alignment word, must be embedded in the transmit data (in the TS16 position) present  
on the TSER pin and frame aligned to sync signal on the TS pin.  
Note 1:  
In addition to setting the TMODE bits to 6312kHz Synchronization Interface mode, the Transmit PLL must also be  
Note 2:  
configured to transmit a 6312kHz signal through the Transmit PLL Control Register (TPCR.6 and TPCR.7).  
6.6 MCLK Pre-Scaler  
Table 6-7. MCLK Pre-Scaler for T1 Mode  
MPS1  
MPS0  
JACKS  
MCLK  
(MHz)  
1.544  
PIN 16  
PIN 15  
PIN 46  
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
3.088  
6.176  
12.352  
2.048  
4.096  
8.192  
16.384  
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DS26503 T1/E1/J1 BITS Element  
Table 6-8. MCLK Pre-Scaler for E1 Mode  
MPS1  
MPS0  
JACKS  
MCLK  
(MHz)  
2.048  
PIN 16  
PIN 15  
PIN 46  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Reserved  
4.096  
Reserved  
8.192  
Reserved  
16.384  
Reserved  
6.7 Other Hardware Controller Mode Features  
Table 6-9. Other Operational Modes  
PIN  
DESCRIPTION  
NAME  
RS Mode Select: Selects frame or multiframe pulse at RS pin.  
RSM  
0 = frame mode  
PIN 1  
1 = multiframe mode  
TS Mode Select: In T1 or E1 operation, selects frame or multiframe mode for the TS pin.  
TSM  
PIN2  
0 = frame mode  
1 = multiframe mode  
Remote Loopback Enable: In this loopback, data input to the framer portion of the  
DS26503 will be transmitted back to the transmit portion of the LIU. Data will continue to  
RLB  
pass through the receive side framer of the DS26503 as it would normally and the data  
from the transmit side formatter will be ignored.  
0 = loopback disabled  
PIN 60  
1 = loopback enabled  
Transmit AIS  
TAIS  
0 = normal transmission  
PIN 10  
1 = transmit AIS alarm  
Receive and Transmit HDB3/B8ZS Enable  
0 = HDB3/B8ZS disabled  
HBE  
PIN 55  
1 = HDB3/B8ZS enabled  
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DS26503 T1/E1/J1 BITS Element  
7. PROCESSOR INTERFACE  
The DS26503 is controlled via a nonmultiplexed (BIS[1:0] = 01) or a multiplexed (BIS[1:0] = 00)  
parallel bus. There is also a serial bus mode option, as well as a hardware mode of operation. The bus  
interface type is selected by BIS1 and BIS0 as shown in Table 7-1.  
Table 7-1. Port Mode Select  
BIS1  
BIS0  
PORT MODE  
0
0
1
1
0
1
0
1
Parallel Port Mode (Multiplexed)  
Parallel Port Mode (Nonmultiplexed)  
Serial Port Mode (SPI)  
Hardware Mode  
7.1 Parallel Port Functional Description  
In parallel mode, the DS26503 can operate with either Intel or Motorola bus timing configurations. If the  
BTS pin is tied low, Intel timing will be selected; if tied high, Motorola timing will be selected. All  
Motorola bus signals are listed in parentheses (). See the timing diagrams in the AC Electrical  
Characteristics section for more details.  
7.2 SPI Serial Port Interface Functional Description  
A serial SPI bus interface is selected when bus select is 10 (BIS[1:0] = 10). In this mode, a master/slave  
relationship is enabled on the serial port with three signal lines (SCK, MOSI, and MISO) and a chip  
select (CS), with the DS26503 acting as the slave. Port read/write timing is not related to the system  
read/write timing, thus allowing asynchronous, half-duplex operation. See the AC Electrical  
Characteristics section for the AC timing characteristics of the serial port.  
7.2.1 Clock Phase and Polarity  
Clock Phase and Polarity are selected by the CPHA and CPOL pins. The slave device should always be  
configured to match the bus master. See the SPI Serial Port Mode section for detailed functional timing  
diagrams.  
7.2.2 Bit Order  
The most significant bit (MSB) of each byte is transmitted first.  
7.2.3 Control Byte  
The bus master will transmit two control bytes following a chip select to a slave device. The MSB will be  
a R/W bit (1=read, 0=write). The next 6 bits will be padded with 0s. The LSB of the first byte will be  
A[7]. The second control byte will be the address bits (A[6:0]) of the target register, followed by a Burst  
bit in the LSB position (1=Burst, 0=Non-burst).  
7.2.4 Burst Mode  
The last bit of the second control byte (LSB) is the Burst mode bit. When the Burst bit is enabled (set to  
1) and a read operation is performed, the register address is automatically incremented after the LSB of  
the previous byte read to the next register address. Data will be available on the next clock edge following  
the LSB of the previous byte read. When the Burst bit is enabled (set to 1) and a write operation is  
performed, the register address will be automatically incremented to the next byte boundary following the  
LSB of the previous register write, and 8 more data bits will be expected on the serial bus. Burst accesses  
30 of 123  
 
DS26503 T1/E1/J1 BITS Element  
are terminated when CS is removed. If CS is removed before all 8 bits of the data are read, the remaining  
data will be lost. If CS is removed before all 8 bits of data are written to the part, no write access will  
occur and the target register will not be updated.  
Note: During a Burst read access, data must be fetched internally to the part as the LSB of the previous  
byte is transmitted out. If this pre-fetch read access occurs to a Clear-On-Read register or a FIFO register  
address, and the Burst access is terminated without reading this byte out of the port, the data will be lost  
and/or the register cleared. Users should not terminate their Burst Read accesses at the address byte  
proceeding a Clear-On-Read register or a FIFO register. Data loss could occur due to the internal pre-  
fetch operation performed by the interface.  
7.2.5 Register Writes  
The register write sequence is shown in the functional timing diagrams in Section 17. After a CS, the bus  
master transmits a write control byte containing the R/W bit, the target register address, and the Burst bit.  
These two control bytes will be followed by the data byte to be written. After the first data byte, if the  
Burst bit is set, the DS26503 auto-increments its address counter and writes each byte received to the next  
higher address location. After writing address FFh, the address counter rolls over to 00h and continues to  
auto-increment.  
7.2.6 Register Reads  
The register read sequence is shown in Section 17. After a CS, the bus master transmits a read control  
byte containing the R/W bit, the target register address, and the Burst bit. After these two control bytes,  
the DS26503 responds with the requested data byte. After the first data byte, if the Burst bit is set, the  
DS26503 auto-increments its address counter and transmits the byte stored in the next higher address  
location. Note the warning mentioned above as data loss could potentially occur due to the data pre-fetch  
that is required to support this mode. After reading address FFh, the address counter rolls over to 00h and  
continues to auto-increment.  
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DS26503 T1/E1/J1 BITS Element  
7.3 Register Map  
Table 7-2. Register Map Sorted By Address  
REGISTER  
ABBREVIATION  
TSTRREG  
IOCR1  
IOCR2  
T1RCR1  
T1RCR2  
T1TCR1  
T1TCR2  
T1CCR  
MCREG  
TPCR  
ADDRESS TYPE  
REGISTER NAME  
Test Reset Register  
00  
01  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
I/O Configuration Register 1  
I/O Configuration Register 2  
T1 Receive Control Register 1  
T1 Receive Control Register 2  
T1 Transmit Control Register 1  
T1 Transmit Control Register 2  
T1 Common Control Register  
Mode Configuration Register  
Transmit PLL Control Register  
Reserved  
02  
03  
04  
05  
06  
07  
08  
09  
0A  
0B  
0C  
0D  
0E  
0F  
10  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
R
Device Identification Register  
Information Register 1  
Information Register 2  
Interrupt Information Register  
Status Register 1  
IDR  
11  
R
INFO1  
INFO2  
IIR  
12  
R
13  
R
14  
R
SR1  
15  
R/W  
R
Interrupt Mask Register 1  
Status Register 2  
IMR1  
SR2  
16  
17  
R/W  
R
Interrupt Mask Register 2  
Status Register 3  
IMR2  
SR3  
18  
19  
R/W  
R
Interrupt Mask Register 3  
Status Register 4  
IMR3  
SR4  
1A  
1B  
1C  
1D  
1E  
1F  
20  
R/W  
R
Interrupt Mask Register 4  
Information Register 3  
E1 Receive Control Register  
E1 Transmit Control Register  
BOC Control Register  
Loopback Control Register  
Reserved  
IMR4  
INFO3  
E1RCR  
E1TCR  
BOCC  
LBCR  
R/W  
R/W  
R/W  
R/W  
21-2F  
30  
31  
R/W  
R/W  
R/W  
R/W  
R/W  
Line Interface Control 1  
Line Interface Control 2  
Line Interface Control 3  
Line Interface Control 4  
Transmit Line Build-Out Control  
Reserved  
Transmit Align Frame Register  
Transmit Non-Align Frame Register  
Transmit Si Align Frame  
LIC1  
LIC2  
32  
LIC3  
33  
LIC4  
34  
TLBC  
35-3F  
40  
R/W  
R/W  
R/W  
TAF  
41  
42  
TNAF  
TSiAF  
32 of 123  
DS26503 T1/E1/J1 BITS Element  
REGISTER  
ABBREVIATION  
TSiNAF  
TRA  
ADDRESS TYPE  
REGISTER NAME  
43  
44  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
Transmit Si Non-Align Frame  
Transmit Remote Alarm Bits  
Transmit Sa4 Bits  
45  
TSa4  
46  
Transmit Sa5 Bits  
TSa5  
47  
Transmit Sa6 Bits  
TSa6  
48  
Transmit Sa7 Bits  
TSa7  
49  
Transmit Sa8 Bits  
TSa8  
4A  
4B-4F  
50  
Transmit Sa Bit Control Register  
Reserved  
TSACR  
R
Receive FDL Register  
Transmit FDL Register  
Receive Facility Data Link Match Register 1  
Receive Facility Data Link Match Register 2  
Reserved  
RFDL  
51  
R/W  
R/W  
R/W  
TFDL  
52  
RFDLM1  
RFDLM2  
53  
54-55  
56  
R
Receive Align Frame Register  
Receive Non-Align Frame Register  
Receive Si Align Frame  
Receive Si Non-Align Frame  
Receive Remote Alarm Bits  
Receive Sa4 Bits  
RAF  
RNAF  
57  
R
58  
R
RSiAF  
RSiNAF  
RRA  
59  
R
5A  
5B  
5C  
5D  
5E  
5F  
R
R
RSa4  
R
Receive Sa5 Bits  
RSa5  
R
Receive Sa6 Bits  
RSa6  
R
Receive Sa7 Bits  
RSa7  
R
Receive Sa8 Bits  
RSa8  
60-EF  
F0  
F1  
Reserved  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
Test Register 1  
TEST1*  
TEST2*  
TEST3*  
TEST4*  
TEST5*  
TEST6*  
TEST7*  
TEST8*  
TEST9*  
TEST10*  
TEST11*  
TEST12*  
TEST13*  
TEST14*  
TEST15*  
TEST16*  
Test Register 2  
F2  
Test Register 3  
F3  
Test Register 4  
F4  
Test Register 5  
F5  
Test Register 6  
F6  
Test Register 7  
F7  
Test Register 8  
F8  
Test Register 9  
F9  
Test Register 10  
FA  
FB  
FC  
FD  
FE  
FF  
Test Register 11  
Test Register 12  
Test Register 13  
Test Register 14  
Test Register 15  
Test Register 16  
*TEST1 to TEST16 registers are used only by the factory.  
33 of 123  
DS26503 T1/E1/J1 BITS Element  
7.3.1 Power-Up Sequence  
The DS26503 contains an on-chip power-up reset function, which automatically clears the writeable  
register space immediately after power is supplied to the device. The user can issue a chip reset at any  
time. Issuing a reset will disrupt signals flowing through the DS26503 until the device is reprogrammed.  
The reset can be issued through hardware using the TSTRST pin or through software using the SFTRST  
function in the master mode register. The LIRST (LIC2.6) should be toggled from zero to one to reset the  
line interface circuitry. (It will take the DS26503 about 40ms to recover from the LIRST bit being  
toggled.)  
7.3.2 Test Reset Register  
Register Name:  
TSTRREG  
Test Reset Register  
00h  
Register Description:  
Register Address:  
Bit #  
7
0
6
0
5
TEST1  
0
4
TEST0  
0
3
0
2
0
1
0
0
SFTRST  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Software Issued Reset (SFTRST). A zero-to-one transition causes the register space in the DS26503 to be cleared. A  
reset clears all configuration and status registers. The bit automatically clears itself when the reset has completed.  
Bits 1-3/Unused, must be set = 0 for proper operation.  
Bits 4-5/Test Mode Bits (TEST0, TEST1). Test modes are used to force the output pins of the DS26503 into known states.  
This can facilitate the checkout of assemblies during the manufacturing process and also be used to isolate devices from shared  
buses.  
TEST1  
TEST0  
Effect On Output Pins  
0
0
1
1
0
1
0
1
Operate normally  
Force all output pins into tri-state (including all I/O pins and parallel port pins)  
Force all output pins low (including all I/O pins except parallel port pins)  
Force all output pins high (including all I/O pins except parallel port pins)  
Bits 6-7/Unused, must be set = 0 for proper operation.  
34 of 123  
DS26503 T1/E1/J1 BITS Element  
7.3.3 Mode Configuration Register  
Register Name:  
MCREG  
Register Description:  
Register Address:  
Mode Configuration Register  
08h  
Bit #  
7
6
5
4
3
2
1
0
Name  
Default  
HW  
TMODE3 TMODE2 TMODE1 TMODE0 RMODE3 RMODE2 RMODE1 RMODE0  
0
0
0
0
0
0
0
0
TMODE3 TMODE2 TMODE1 TMODE0 RMODE3 RMODE2 RMODE1 RMODE0  
PIN 62 PIN 48 PIN 49 PIN 14 PIN 64 PIN 61 PIN 4 PIN 3  
Mode  
Bit 0-3/Receive Mode Configuration (RMODE[3:0]). Used to select the operating mode of the receive path for the  
DS26503.  
RMODE3 RMODE2 RMODE1 RMODE0  
Receive Path Operating Mode  
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
T1 D4  
T1 ESF  
J1 D4  
J1 ESF  
E1 FAS  
E1 CAS  
E1 CRC4  
E1 CAS and CRC4  
E1 G.703 2048kHz Synchronization Interface  
Reserved  
Reserved  
6312kHz Synchronization Interface  
Reserved  
Reserved  
Reserved  
Reserved  
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DS26503 T1/E1/J1 BITS Element  
Bit 4-7/ Transmit Mode Configuration (TMODE[3:0]). Used to select the operating mode of the transmit path for the  
DS26503.  
TMODE3 TMODE2 TMODE1 TMODE0  
Transmit Path Operating Mode  
0
0
0
0
0
0
0
1
T1 D4  
T1 ESF (Note: In this mode the TFSE (T1TCR2.6) bit should be  
set = 0.)  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
1
1
1
0
0
1
1
0
0
0
1
0
0
1
0
0
1
0
1
0
1
0
1
J1 D4  
J1 ESF  
E1 FAS  
E1 FAS + CAS (Note 1)  
Reserved  
E1 CRC4  
E1 CRC4 + CAS (Note 1)  
Reserved  
E1 G.703 2048 kHz Synchronization Interface  
Reserved  
Reserved  
6312kHz Synchronization Interface (Note 2)  
Reserved  
Reserved  
Note 1: The DS26503 does not have an internal source for CAS signaling and multiframe alignment generation. CAS signaling, and the  
multiframe alignment word, must be embedded in the transmit data (in the TS16 position) present on the TSER pin and frame  
aligned to sync signal on the TS pin.  
Note 2: In addition to setting the TMODE bits to 6312kHz Synchronization Interface mode, the Transmit PLL must also be configured to  
transmit a 6312kHz signal through the Transmit PLL Control Register (TPCR.6 and TPCR.7)  
Register Name:  
TPCR  
Register Description:  
Register Address:  
Transmit PLL Control Register  
09h  
Bit #  
7
6
5
PLLOS  
0
4
TPLLIFS0  
0
3
2
1
0
Name  
Default  
HW  
TPLLOFS0 TPLLOFS1  
TPLLIFS1 TPLLSS  
TCSS1  
0
TCSS0  
0
0
0
0
0
0
0
0
0
TCSS1  
PIN 31  
TCSS0  
PIN 63  
0
0
Mode  
For more information on all the bits in the Transmit PLL control register, refer to Figure 3-3.  
Bit 0-1/Transmit Clock (TX CLOCK) Source Select (TCSS[1:0]). These bits control the output of the TX PLL Clock Mux  
function. See Figure 3-3.  
Transmit Clock (TX CLOCK) Source  
TCSS1  
TCSS0  
(See Figure 3-3)  
The TCLK pin is the source of transmit clock.  
The PLL_CLK is the source of transmit clock.  
The scaled signal present at MCLK as the transmit clock.  
The signal present at RCLK is the transmit clock.  
0
0
1
1
0
1
0
1
Bit 2/Transmit PLL_CLK Source Select (TPLLSS). Selects the reference signal for the TX PLL.  
0 = Use the recovered network clock. This is the same clock available at the RCLK pin (output).  
1 = Use the externally provided clock present at the TCLK pin.  
36 of 123  
DS26503 T1/E1/J1 BITS Element  
Bit 3-4/Transmit PLL Input Frequency Select (TPLLIFS[1:0]). These bits are used to indicate the reference frequency  
being input to the TX PLL.  
TPLLIFS1 TPLLIFS0  
Input Frequency  
0
0
1
1
0
1
0
1
1.544MHz  
2.048MHz  
6312kHz  
Bit 5/ PLL_OUT Select (PLLOS). This bit selects the source for the PLL_OUT pin. See Figure 3-3.  
0 = PLL_OUT is sourced directly from the TX PLL.  
1 = PLL_OUT is the output of the TX PLL mux.  
Bit 6-7/Transmit PLL Output Frequency Select (TPLLOFS[1:0]). These bits are used to select the TX PLL output  
frequency.  
TPLLOFS1 TPLLOFS0  
Output Frequency  
0
0
1
1
0
1
0
1
1.544MHz  
2.048MHz  
6312kHz  
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DS26503 T1/E1/J1 BITS Element  
7.4 Interrupt Handling  
Various alarms, conditions, and events in the DS26503 can cause interrupts. For simplicity, these are all  
referred to as events in this explanation. All STATUS registers can be programmed to produce interrupts.  
Each status register has an associated interrupt mask register. For example, SR1 (Status Register 1) has an  
interrupt control register called IMR1 (Interrupt Mask Register 1). Status registers are the only sources of  
interrupts in the DS26503. On power-up, all writeable registers are automatically cleared. Since bits in  
the IMRx registers have to be set = 1 to allow a particular event to cause an interrupt, no interrupts can  
occur until the host selects which events are to product interrupts. Since there are potentially many  
sources of interrupts on the DS26503, several features are available to help sort out and identify which  
event is causing an interrupt. When an interrupt occurs, the host should first read the IIR register  
(interrupt information register) to identify which status register(s) is producing the interrupt. Once that is  
determined, the individual status register or registers can be examined to determine the exact source.  
Once an interrupt has occurred, the interrupt handler routine should clear the IMRx registers to stop  
further activity on the interrupt pin. After all interrupts have been determined and processed, the interrupt  
hander routine should restore the state of the IMRx registers.  
7.5 Status Registers  
When a particular event or condition has occurred (or is still occurring in the case of conditions), the  
appropriate bit in a status register will be set to a one. All the status registers operate in a latched fashion,  
which means that if an event or condition occurs a bit is set to a one. It will remain set until the user reads  
that bit. An event bit will be cleared when it is read and it will not be set again until the event has  
occurred again. Condition bits such as RLOS, etc., will remain set if the alarm is still present.  
The user will always precede a read of any of the status registers with a write. The byte written to the  
register will inform the DS26503 which bits the user wishes to read and have cleared. The user will write  
a byte to one of these registers, with a one in the bit positions he or she wishes to read and a zero in the  
bit positions he or she does not wish to obtain the latest information on. When a one is written to a bit  
location, the read register will be updated with the latest information. When a zero is written to a bit  
position, the read register will not be updated and the previous value will be held. A write to the status  
registers will be immediately followed by a read of the same register. This write-read scheme allows an  
external microcontroller or microprocessor to individually poll certain bits without disturbing the other  
bits in the register. This operation is key in controlling the DS26503 with higher-order languages.  
Status register bits are divided into two groups: condition bits and event bits. Condition bits are typically  
network conditions such as loss of frame, or all-ones detect. Event bits are typically markers such as the  
one-second timer. Each status register bit is labeled as a condition or event bit. Some of the status  
registers have bits for both the detection of a condition and the clearance of the condition. For example,  
SR2 has a bit that is set when the device goes into a loss of frame state (SR2.0, a condition bit) and a bit  
that is set (SR2.4, an event bit) when the loss of frame condition clears (goes in sync). Some of the status  
register bits (condition bits) do not have a separate bit for the “condition clear” event but rather the status  
bit can produce interrupts on both edges, setting, and clearing. These bits are marked as “double interrupt  
bits.” An interrupt will be produced when the condition occurs and when it clears.  
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DS26503 T1/E1/J1 BITS Element  
7.6 Information Registers  
Information registers operate the same as status registers except they cannot cause interrupts. INFO3  
register is a read-only register and it reports the status of the E1 synchronizer in real time. INFO3  
information bits are not latched, and it is not necessary to precede a read of these bits with a write.  
7.7 Interrupt Information Registers  
The Interrupt Information Registers provide an indication of which Status Registers (SR1 through SR3)  
are generating an interrupt. When an interrupt occurs, the host can read IIR to quickly identify which of  
the three status registers are causing the interrupt.  
Register Name:  
IIR  
Register Description:  
Register Address:  
Interrupt Information Register  
13h  
Bit #  
7
0
6
0
5
0
4
0
3
SR4  
0
2
SR3  
0
1
SR2  
0
0
SR1  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Status Register 1 (SR1).  
0 = Status Register 1 interrupt not active.  
1 = Status Register 1 interrupt active.  
Bit 1/Status Register 2 (SR2).  
0 = Status Register 1 interrupt not active.  
1 = Status Register 1 interrupt active.  
Bit 2/Status Register 3 (SR3).  
0 = Status Register 1 interrupt not active.  
1 = Status Register 1 interrupt active.  
Bit 3/Status Register 4 (SR4).  
0 = Status Register 1 interrupt not active.  
1 = Status Register 1 interrupt active.  
Bit 4/Unused.  
Bit 5/Unused.  
Bit 6/Unused.  
Bit 7/Unused.  
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DS26503 T1/E1/J1 BITS Element  
8. T1 FRAMER/FORMATTER CONTROL REGISTERS  
The T1 framer portion of the DS26503 is configured via a set of five control registers. Typically, the  
control registers are only accessed when the system is first powered up. Once the DS26503 has been  
initialized, the control registers will only need to be accessed when there is a change in the system  
configuration. There are two receive control registers (T1RCR1 and T1RCR2), two transmit control  
registers (T1TCR1 and T1TCR2), and a common control register (T1CCR). Each of these registers is  
described in this section.  
8.1 T1 Control Registers  
Register Name:  
T1RCR1  
Register Description:  
Register Address:  
T1 Receive Control Register 1  
03h  
Bit #  
7
0
6
ARC  
0
5
OOF1  
0
4
OOF2  
0
3
SYNCC  
0
2
SYNCT  
0
1
SYNCE  
0
0
RESYNC  
0
Name  
Default  
HW  
0
0
0
0
0
0
0
0
Mode  
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.  
Bit 1/Sync Enable (SYNCE).  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 2/Sync Time (SYNCT).  
0 = qualify 10 bits  
1 = qualify 24 bits  
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  
Bits 4 to 5/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 6/Auto Resync Criteria (ARC).  
0 = resync on OOF or RLOS event  
1 = resync on OOF only  
Bit 7/Unused, must be set = 0 for proper operation.  
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DS26503 T1/E1/J1 BITS Element  
Register Name:  
T1RCR2  
Register Description:  
Register Address:  
T1 Receive Control Register 2  
04h  
Bit #  
7
0
6
0
5
4
0
3
0
2
0
1
RJC  
0
0
RD4YM  
0
Name  
Default  
HW  
RB8ZS  
0
HBE  
PIN55  
0
0
0
0
0
0
0
Mode  
Bit 0/Receive Side D4 Yellow Alarm Select (RD4YM).  
0 = zeros in bit 2 of all channels  
1 = a one in the S-bit position of frame 12 (J1 Yellow Alarm Mode)  
Bit 1/Receive Japanese CRC6 Enable (RJC).  
0 = use ANSI/AT&T/ITU CRC6 calculation (normal operation)  
1 = use Japanese standard JT–G704 CRC6 calculation  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/Unused, must be set = 0 for proper operation.  
Bit 5/Receive B8ZS Enable (RB8ZS).  
0 = B8ZS disabled  
1 = B8ZS enabled  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
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DS26503 T1/E1/J1 BITS Element  
Register Name:  
T1TCR1  
Register Description:  
Register Address:  
T1 Transmit Control Register 1  
05h  
Bit #  
7
TJC  
6
TFPT  
0
5
TCPT  
0
4
0
3
0
2
0
1
0
0
TYEL  
0
Name  
Default  
HW  
0
RMODEx  
PINS  
0
0
0
0
0
0
0
Mode  
Bit 0/Transmit Yellow Alarm (TYEL).  
0 = do not transmit yellow alarm  
1 = transmit yellow alarm  
Bit 1/Unused, must be set = 0 for proper operation.  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/Unused, must be set = 0 for proper operation.  
Bit 5/Transmit CRC Pass-Through (TCPT).  
0 = source CRC6 bits internally  
1 = CRC6 bits sampled at TSER during F-bit time  
Bit 6/Transmit F-Bit Pass-Through (TFPT).  
0 = F bits sourced internally  
1 = F bits sampled at TSER  
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  
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DS26503 T1/E1/J1 BITS Element  
Register Name:  
T1TCR2  
Register Description:  
Register Address:  
T1 Transmit Control Register 2  
06h  
Bit #  
7
6
TFSE  
1
5
0
4
FBCT2  
0
3
FBCT1  
0
2
TD4YM  
0
1
0
0
TB7ZS  
0
Name  
Default  
HW  
TB8ZS  
0
HBE  
PIN 55  
1
0
0
0
0
0
0
Mode  
Bit 0/Transmit-Side Bit 7 Zero-Suppression Enable (TB7ZS).  
0 = no stuffing occurs  
1 = bit 7 forced to a 1 in channels with all 0s  
Bit 1/Unused, must be set = 0 for proper operation.  
Bit 2/Transmit-Side D4 Yellow Alarm Select (TD4YM).  
0 = 0s in bit 2 of all channels  
1 = a 1 in the S-bit position of frame 12  
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 frame (loss of  
synchronization).  
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 5/Unused, must be set = 0 for proper operation.  
Bit 6/Transmit Fs-Bit Insertion Enable (TFSE). Only set this bit to a 1 in D4 framing applications. Must be set to 1 to  
source the Fs pattern from the TFDL register. In all other modes this bit must be set = 0.  
0 = Fs-bit insertion disabled  
1 = Fs-bit insertion enabled  
Bit 7/Transmit B8ZS Enable (TB8ZS).  
0 = B8ZS disabled  
1 = B8ZS enabled  
43 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
T1CCR  
Register Description:  
Register Address:  
T1 Common Control Register  
07h  
Bit #  
7
0
6
0
5
0
4
TRAI-CI  
0
3
TAIS-CI  
0
2
0
1
PDE  
0
0
0
Name  
Default  
HW  
0
0
0
0
0
0
0
0
Mode  
Bit 0/Unused, must be set = 0 for proper operation.  
Bit 1/Pulse-Density Enforcer Enable (PDE). The framer always examines the transmit and receive data streams for  
violations of these, 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. When this bit is set to one, the DS26503 forces 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, as B8ZS encoded data streams cannot violate the pulse-density requirements.  
0 = disable transmit pulse-density enforcer  
1 = enable transmit pulse-density enforcer  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Transmit AIS-CI Enable (TAIS-CI). Setting this bit causes the AIS-CI code to be transmitted from the framer to the  
LIU, as defined in ANSI T1.403.  
0 = do not transmit the AIS-CI code  
1 = transmit the AIS-CI code  
Bit 4/Transmit RAI-CI Enable (TRAI-CI). Setting this bit causes the ESF RAI-CI code to be transmitted in the FDL bit  
position.  
0 = do not transmit the ESF RAI-CI code  
1 = transmit the ESF RAI-CI code  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
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DS26503 T1/E1/J1 BITS Element  
Table 8-1. T1 Alarm Criteria  
ALARM  
SET CRITERIA  
CLEAR CRITERIA  
Blue Alarm (AIS) (Note 1)  
Over a 3ms window, five or  
fewer zeros are received  
Over a 3ms window, six or more zeros  
are received  
Yellow Alarm (RAI)  
D4 Bit-2 Mode (T1RCR2.0 = 0) Bit 2 of 256 consecutive  
channels is set to zero for at  
Bit 2 of 256 consecutive channels is  
set to zero for less than 254  
occurrences  
least 254 occurrences  
D4 12th F-bit Mode (T1RCR2.0 12th framing bit is set to one  
= 1; this mode is also referred to for two consecutive  
as the “Japanese Yellow Alarm”) occurrences  
12th framing bit is set to zero for two  
consecutive occurrences  
ESF Mode  
16 consecutive patterns of  
00FF appear in the FDL  
192 consecutive zeros are  
received  
14 or fewer patterns of 00FF hex out of  
16 possible appear in the FDL  
14 or more ones out of 112 possible bit  
positions are received, starting with the  
first one received  
Red Alarm (RLOS) (Also  
referred to as Loss Of Signal)  
Note: The definition of Blue Alarm (or Alarm Indication Signal) is an unframed, all-ones signal. Blue Alarm 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 Blue Alarm  
criteria in the DS26503 has been set to achieve this performance.  
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DS26503 T1/E1/J1 BITS Element  
9. E1 FRAMER/FORMATTER CONTROL REGISTERS  
The E1 framer portion of the DS26503 is configured via a set of two control registers. Typically, the  
control registers are only accessed when the system is first powered up. Once the DS26503 has been  
initialized, the control registers will only need to be accessed when there is a change in the system  
configuration. There is one receive control register (E1RCR) and one transmit control register (E1TCR).  
There are also two information registers and a status register, as well as an interrupt mask register. Each  
of these registers is described in this section.  
9.1 E1 Control Registers  
Register Name:  
E1RCR  
Register Description:  
Register Address:  
E1 Receive Control Register  
1Dh  
Bit #  
7
0
6
RLOSA  
0
5
4
0
3
0
2
FRC  
0
1
SYNCE  
0
0
RESYNC  
0
Name  
Default  
HW  
RHDB3  
0
HBE  
PIN 55  
0
0
0
0
0
0
0
Mode  
Bit 0/Resync (RESYNC). When toggled from low to high, a resync is initiated. Must be cleared and set again for a subsequent  
resync.  
Bit 1/Sync Enable (SYNCE).  
0 = auto resync enabled  
1 = auto resync disabled  
Bit 2/Frame Resync Criteria (FRC).  
0 = resync if FAS received in error three consecutive times  
1 = resync if FAS or bit 2 of non-FAS is received in error three consecutive times  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/Unused, must be set = 0 for proper operation.  
Bit 5/Receive HDB3 Enable (RHDB3).  
0 = HDB3 disabled  
1 = HDB3 enabled  
Bit 6/Receive Loss Of Signal (RLOS). Alternate Criteria (RLOSA). Defines the criteria for a Receive Loss Of Signal  
condition.  
0 = RLOS declared upon 255 consecutive zeros (125µs)  
1 = RLOS declared upon 2048 consecutive zeros (1ms)  
Bit 7/Unused, must be set = 0 for proper operation.  
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DS26503 T1/E1/J1 BITS Element  
Table 9-1. E1 Sync/Resync Criteria  
FRAME OR  
MULTIFRAME  
LEVEL  
SYNC CRITERIA  
RESYNC CRITERIA  
Three consecutive incorrect FAS  
ITU SPEC.  
FAS  
FAS present in frame N and  
G.706  
4.1.1  
4.1.2  
N + 2, and FAS not present in received  
frame N + 1  
Alternate: (E1RCR.2 = 1) The above  
criteria is met or three consecutive  
incorrect bit 2 of non-FAS received  
915 or more CRC4 code words out of  
1000 received in error  
CRC4  
CAS  
Two valid MF alignment  
words found within 8ms  
Valid MF alignment word  
found and previous time slot  
16 contains code other than  
all zeros  
G.706  
4.2 and 4.3.2  
G.732 5.2  
Two consecutive MF alignment  
words received in error  
Register Name:  
E1TCR  
Register Description:  
Register Address:  
E1 Transmit Control Register  
1Eh  
Bit #  
7
TFPT  
0
6
0
5
0
4
TSiS  
0
3
0
2
0
1
0
0
Name  
Default  
HW  
THDB3  
0
HBE  
PIN 55  
0
0
0
0
0
0
0
Mode  
Bit 0/Unused, must be set = 0 for proper operation.  
Bit 1/Transmit HDB3 Enable (THDB3).  
0 = HDB3 disabled  
1 = HDB3 enabled  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Unused, must be set = 0 for proper operation.  
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, E1TCR1.7 must be set to 0)  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
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  
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DS26503 T1/E1/J1 BITS Element  
9.2 E1 Information Registers  
Register Name:  
INFO2  
Register Description:  
Register Address:  
Information Register 2  
12h  
Bit #  
7
0
6
0
5
0
4
0
3
0
2
CRCRC  
0
1
FASRC  
0
0
CASRC  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/CAS Resync Criteria Met Event (CASRC). Set when two consecutive CAS MF alignment words are received in error.  
Bit 1/FAS Resync Criteria Met Event (FASRC. Set when three consecutive FAS words are received in error.  
Bit 2/CRC Resync Criteria Met Event (CRCRC). Set when 915/1000 codewords are received in error.  
Bit 3/Unused.  
Bit 4/Unused.  
Bit 5/Unused.  
Bit 6/Unused.  
Bit 7/Unused.  
Register Name:  
INFO3  
Register Description:  
Register Address:  
Information Register 3 (Real Time)  
1Ch  
Bit #  
7
CSC5  
0
6
CSC4  
0
5
CSC3  
0
4
CSC2  
0
3
CSC0  
0
2
FASSA  
0
1
0
Name  
Default  
HW  
CASSA CRC4SA  
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/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 2/FAS Sync Active (FASSA). Set while the synchronizer is searching for alignment at the FAS level.  
Bit 3-7/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 (E1RCR.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 will rollover. CSC0 is the LSB of the 6-bit counter. (Note: The second LSB, CSC1, is not  
accessible. CSC1 is omitted to allow resolution to >400ms using 5 bits.)  
48 of 123  
DS26503 T1/E1/J1 BITS Element  
Table 9-2. E1 Alarm Criteria  
ITU  
ALARM  
RLOF  
SET CRITERIA  
CLEAR CRITERIA  
SPEC.  
An RLOF condition exists on power-up  
prior to initial synchronization, when a  
resync criteria has been met, or when a  
manual resync has been initiated via  
E1RCR.0  
255 or 2048 consecutive zeros received as In 255-bit times, at least 32  
G.775/G.962  
RLOS  
RRA  
determined by E1RCR.0  
ones are received  
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  
O.162  
2.1.4  
Fewer than three zeros in two frames (512 More than two zeros in two  
O.162  
RUA1  
RDMA  
V52LNK  
bits)  
frames (512 bits)  
1.6.1.2  
Bit 6 of time slot 16 in frame 0 has been  
set for two consecutive multiframes  
Two out of three Sa7 bits are zero  
G.965  
Register Name:  
IDR  
Register Description:  
Register Address:  
Device Identification Register  
10h  
Bit #  
7
ID7  
0
6
ID6  
0
5
ID5  
0
4
ID4  
1
3
ID3  
N
2
ID2  
N
1
ID1  
N
0
ID0  
N
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bits 0-3/Chip Revision Bits (ID0 to ID3). 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.  
Bits 4-7/Device ID (ID4 to ID7). The upper four bits of the IDR are used to display the DS26503 ID. The DS26503 ID is  
0001.  
49 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
SR2  
Register Description:  
Register Address:  
Status Register 2  
16h  
Bit #  
7
RYELC  
0
6
RAISC  
0
5
RLOSC  
0
4
RLOFC  
0
3
RYEL  
0
2
1
0
Name  
Default  
HW  
RAIS  
0
RLOS  
0
RLOF  
0
RAIS  
PIN 29  
RLOS  
PIN 32  
LOF  
PIN 30  
X
X
X
X
X
Mode  
Bit 0/Receive Loss of Frame Condition (RLOF). Set when the DS26503 is not synchronized to the received data stream.  
Bit 1/Receive Loss Of Signal Condition (RLOS). Set when 255 (or 2048 if E1RCR.6 = 1) E1 mode or 192 T1 mode  
consecutive zeros have been detected. In 6312kHz Synchronization Interface Mode, this bit will be set when the signal  
received is out of range as defined by the G.703 Appendix II specification.  
Bit 2/Receive Alarm Indication Signal (T1= Blue Alarm, E1= AIS) Condition (RAIS). Set when an unframed all-ones  
code is received.  
Bit 3/Receive Yellow Alarm Condition (RYEL). (T1 only) Set when a yellow alarm is received.  
Bit 4/Receive Loss of Frame Clear Event (RLOFC). Set when the framer achieves synchronization; will remain set until  
read.  
Bit 5/Receive Loss Of Signal Clear Event (RLOSC). Set when loss of signal condition is no longer detected.  
Bit 6/Receive Alarm Indication Signal Clear Event (RAISC). Set when the unframed all-ones condition is no longer  
detected.  
Bit 7/Receive Yellow Alarm Clear Event (RYELC). (T1 only) Set when the yellow alarm condition is no longer detected.  
50 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
IMR2  
Register Description:  
Register Address:  
Interrupt Mask Register 2  
17h  
Bit #  
7
RYELC  
0
6
RAISC  
0
5
RLOSC  
0
4
RLOFC  
0
3
RYEL  
0
2
RAIS  
0
1
RLOS  
0
0
RLOF  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Receive Loss of Frame Condition (RLOF).  
0 = interrupt masked  
1 = interrupt enabled–interrupts on rising edge only  
Bit 1/Receive Loss Of Signal Condition (RLOS).  
0 = interrupt masked  
1 = interrupt enabled–interrupts on rising edge only  
Bit 2/Receive Alarm Indication Signal Condition (RAIS).  
0 = interrupt masked  
1 = interrupt enabled–interrupts on rising edge only  
Bit 3/Receive Yellow Alarm Condition (RYEL).  
0 = interrupt masked  
1 = interrupt enabled–interrupts on rising edge only  
Bit 4/Receive Loss of Frame Clear Event (RLOFC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5/Receive Loss Of Signal Condition Clear (RLOSC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6/Receive Alarm Indication Signal Clear Event (RAISC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 7/Receive Yellow Alarm Clear Event (RYELC).  
0 = interrupt masked  
1 = interrupt enabled  
51 of 123  
DS26503 T1/E1/J1 BITS Element  
10. I/O PIN CONFIGURATION OPTIONS  
Register Name:  
IOCR1  
Register Description:  
Register Address:  
I/O Configuration Register 1  
01h  
Bit #  
7
0
6
RSMS2  
0
5
RSMS1  
0
RSM  
PIN 1  
4
RLOFF  
0
3
TSDW  
0
2
1
TSIO  
0
0
ODF  
0
Name  
Default  
HW  
TSM  
0
TSM  
PIN 2  
0
0
0
0
0
0
Mode  
Bit 0/Output Data Format (ODF).  
0 = bipolar data at TPOS and TNEG  
1 = NRZ data at TPOS; TNEG = 0  
Bit 1/TS I/O Select (TSIO). This bit determines whether the TS pin is an input or and output. See Table 10-1.  
0 = TS is an input  
1 = TS is an output  
Bit 2/TS Mode Select (TSM). In T1 or E1 operation, selects frame or multiframe mode for the TS pin. In 6312kHz mode, this  
bit should be set = 0. See Table 10-1.  
0 = frame mode  
1 = multiframe mode  
Bit 3/Transmit Signaling Double-Wide Sync (TSDW). In T1 mode, setting this bit = 1 and setting TSIO = 1 will cause the  
sync-pulse output on TS to be two clocks wide during signaling frames. In E1 or 6312kHz mode, this bit should be set = 0. See  
Table 10-1.  
0 = (T1) normal sync pulses  
1 = (T1) double-wide sync pulses during signaling frames  
Bit 4/ RLOF Output Function (RLOFF). In T1 or E1 receive mode this bit determines the function of the RLOF pin. In  
6312kHz receive mode, this bit should be set = 0.  
0 = receive loss of frame (RLOF)  
1 = loss-of-transmit clock (LOTC)  
Bit 5/RS Mode Select 1(RSMS1). In T1 or E1 receive mode, this bit selects a frame or multiframe output pulse at RS pin.  
IOCR.6 may be used to select other function for the RS pin.  
0 = frame mode  
1 = multiframe mode  
Bit 6/RS Mode Select 2 (RSMS2). In T1 and E1 receive mode, this bit along with IOCR.5 selects the function of the RS pin.  
T1 Mode: (when IOCR.5 set = 0)  
0 = do not pulse double-wide in signaling frames  
1 = do pulse double-wide in signaling frames  
E1 Mode: (when IOCR.5 set = 1)  
0 = RS outputs CAS multiframe boundaries  
1 = RS outputs CRC4 multiframe boundaries  
Bit 7/Unused, must be set = 0 for proper operation.  
52 of 123  
DS26503 T1/E1/J1 BITS Element  
Table 10-1. TS Pin Functions  
TRANSMIT  
TS  
IOCR.3  
IOCR.2  
IOCR.1  
MODE  
T1/E1  
T1/E1  
T1/E1  
T1/E1  
FUNCTION  
0
0
0
0
0
0
1
1
0
1
0
1
Frame sync input  
Frame sync output  
Multiframe sync input  
Multiframe sync output  
Table 10-2. RLOF Pin Functions  
RECEIVE  
IOCR.4  
RLOF PIN FUNCTION  
MODE  
T1/E1  
T1/E1  
0
1
Indicate loss of frame  
Indicates loss of transmit clock  
53 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
IOCR2  
Register Description:  
Register Address:  
I/O Configuration Register 2  
02h  
Bit #  
7
6
5
RSINV  
0
4
TSINV  
0
3
0
2
0
1
0
0
0
Name  
RCLKINV TCLKINV  
Default  
HW  
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Unused, must be set = 0 for proper operation.  
Bit 1/Unused, must be set = 0 for proper operation.  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/TS Invert (TSINV).  
0 = no inversion  
1 = invert  
Bit 5/RS Invert (RSINV).  
0 = no inversion  
1 = invert  
Bit 6/TCLK Invert (TCLKINV).  
0 = no inversion  
1 = invert  
Bit 7/RCLK Invert (RCLKINV).  
0 = no inversion  
1 = invert  
54 of 123  
DS26503 T1/E1/J1 BITS Element  
11. T1 SYNCHRONIZATION STATUS MESSAGE  
The DS26503 has a BOC controller to handle SSM services in T1 mode.  
Table 11-1. T1 SSM Messages  
QUALITY  
DESCRIPTION  
BOC CODE  
0000010011111111  
LEVEL  
1
Stratum 1 Traceable  
2
Synchronized Traceablity Unknown  
Stratum 2 Traceable  
0000100011111111  
0000110011111111  
0001000011111111  
0010001011111111  
0010100011111111  
0011000011111111  
0100000011111111  
3
4
Stratum 3 Traceable  
5
SONET Minimum Clock Traceable  
Stratum 4 Traceable  
6
7
Do Not Use For Synchronization  
Reserved For Network Synchronization Use  
User Assignable  
11.1 T1 Bit-Oriented Code (BOC) Controller  
The DS26503 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 typical BITS applications, the BOC controller would be  
used to transmit and receive Synchronization Status Messages in T1 mode over the data link.  
11.2 Transmit BOC  
Bits 0 through 5 in the TFDL register contain the BOC or synchronization status message to be  
transmitted. Setting BOCC.0 = 1 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 BOCC.0 is set. TFSE (T1TCR2.6) must be set =  
0 when using the transmit BOC function.  
To transmit a BOC, use the following:  
1) Write 6-bit code into the TFDL register.  
2) Set SBOC bit in BOCC register = 1.  
55 of 123  
DS26503 T1/E1/J1 BITS Element  
11.3 Receive BOC  
The receive BOC function is enabled by setting BOCC.4 = 1. The RFDL register will now operate as the  
receive BOC message and information register. The lower six bits of the RFDL register (BOC message  
bits) are preset to all ones. When the BOC bits change state, the BOC change of state indicator, SR3.0  
will alert the host. The host will then read the RFDL register to get the BOC message. A change of state  
will occur when either a new BOC code has been present for time determined by the receive BOC filter  
bits, RBF0 and RBF1, in the BOCC register.  
To receive a BOC, use the following:  
1) Set integration time via BOCC.1 and BOCC.2.  
2) Enable the receive BOC function (BOCC.4 = 1).  
3) Enable interrupt (IMR3.0 = 1).  
4) Wait for interrupt to occur.  
5) Read the RFDL register.  
6) The lower six bits of the RFDL register is the message.  
56 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
BOCC  
Register Description:  
Register Address:  
BOC Control Register  
1Fh  
Bit #  
7
0
6
0
5
0
4
RBOCE  
0
3
RBR  
0
2
RBF1  
0
1
0
SBOC  
0
Name  
Default  
HW  
RBF0  
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Send BOC (SBOC). Set = 1 to transmit the BOC code placed in bits 0 to 5 of the TFDL register.  
Bits 1-2/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.  
CONSECUTIVE BOC CODES FOR VALID  
RBF1  
RBF0  
SEQUENCE IDENTIFICATION  
0
0
1
1
0
1
0
1
None  
3
5
7
Bit 3/Receive BOC Reset (RBR). A 0-to-1 transition will reset the BOC circuitry. Must be cleared and set again for a  
subsequent reset.  
Bit 4/Receive BOC Enable (RBOCE). Enables the receive BOC function. The RFDL register will report the received BOC  
code.  
0 = receive BOC function disabled  
1 = receive BOC function enabled. The RFDL register will report BOC messages  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
57 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RFDL (RFDL register bit usage when BOCC.4 = 1)  
Register Description:  
Register Address:  
Receive FDL Register  
50h  
Bit #  
7
0
6
0
5
RBOC5  
0
4
RBOC4  
0
3
RBOC3  
0
2
RBOC2  
0
1
RBOC1  
0
0
RBOC0  
0
Name  
Default  
HW  
0
0
0
0
0
0
0
0
Mode  
Bit 0/BOC Bit 0 (RBOC0).  
Bit 1/BOC Bit 1 (RBOC1).  
Bit 2/BOC Bit 2 (RBOC2).  
Bit 3/BOC Bit 3 (RBOC3).  
Bit 4/BOC Bit 4 (RBOC4).  
Bit 5/BOC Bit 5 (RBOC5).  
Bit 6/This bit position is unused when BOCC.4 = 1.  
Bit 7/This bit position is unused when BOCC.4 = 1.  
Register Name:  
RFDLM1, RFDLM2  
Receive FDL Match Register 1  
Receive FDL Match Register 2  
52h, 53h  
Register Description:  
Register Address:  
Bit #  
7
RFDLM7  
0
6
5
4
3
2
1
0
RFDLM0  
0
Name  
Default  
HW  
RFDLM6 RFDLM5 RFDLM4  
RFDLM3 RFDLM2 RFDLM1  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Receive FDL Match Bit 0 (RFDLM0). LSB of the FDL Match Code.  
Bit 1/Receive FDL Match Bit 1 (RFDLM1).  
Bit 2/Receive FDL Match Bit 2 (RFDLM2).  
Bit 3/Receive FDL Match Bit 3 (RFDLM3).  
Bit 4/Receive FDL Match Bit 4 (RFDLM4).  
Bit 5/Receive FDL Match Bit 5 (RFDLM5).  
Bit 6/Receive FDL Match Bit 6 (RFDLM6).  
Bit 7/Receive FDL Match Bit 7 (RFDLM7). MSB of the FDL Match Code.  
58 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
SR3  
Register Description:  
Register Address:  
Status Register 3  
18h  
Bit #  
7
RAIS-CI  
0
6
LOTC  
0
5
BOCC  
0
4
RFDLAD  
0
3
RFDLF  
0
2
TFDLE  
0
1
RMTCH  
0
0
RBOC  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Receive BOC Detector Change-of-State Event (RBOC). Set whenever the BOC detector sees a change of state to a  
valid BOC. The setting of this bit prompts the user to read the RFDL register.  
Bit 1/Receive FDL Match Event (RMTCH). Set whenever the contents of the RFDL register matches RFDLM1 or  
RFDLM2.  
Bit 2/TFDL Register Empty Event (TFDLE). Set when the transmit FDL buffer (TFDL) empties.  
Bit 3/RFDL Register Full Event (RFDLF). Set when the receive FDL buffer (RFDL) fills to capacity.  
Bit 4/RFDL Abort Detect Event (RFDLAD). Set when eight consecutive ones are received on the FDL.  
Bit 5/BOC Clear Event (BOCC). Set when 30 FDL bits occur without an abort sequence.  
Bit 6/Loss Of Transmit Clock Event (LOTC). Set when the signal at the TCLK pin has not transitioned for approximately  
15 periods of the scaled MCLK.  
Bit 7/Receive AIS-CI Event (RAIS-CI) (T1 Only). Set when the receiver detects the AIS-CI pattern as defined in ANSI  
T1.403.  
59 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
IMR3  
Register Description:  
Register Address:  
Interrupt Mask Register 3  
19h  
Bit #  
7
RAIS-CI  
0
6
LOTC  
0
5
BOCC  
0
4
3
2
TFDLE  
0
1
RMTCH  
0
0
RBOC  
0
Name  
Default  
HW  
RFDLAD RFDLF  
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Receive BOC Detector Change-of-State Event (RBOC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1/Receive FDL Match Event (RMTCH).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2/TFDL Register Empty Event (TFDLE).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3/RFDL Register Full Event (RFDLF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4/RFDL Abort Detect Event (RFDLAD).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5/BOC Clear Event (BOCC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6/ Loss Of Transmit Clock Event (LOTC).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 7/Receive AIS-CI Event (RAIS-CI).  
0 = interrupt masked  
1 = interrupt enabled  
60 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
SR4  
Register Description:  
Register Address:  
Status Register 4  
1Ah  
Bit #  
7
0
6
RSA1  
0
5
RSA0  
0
4
TMF  
0
3
TAF  
0
2
RMF  
0
1
RCMF  
0
0
RAF  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Receive Align Frame Event (RAF). (E1 only) 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.  
Bit 1/Receive CRC4 Multiframe Event (RCMF). (E1 only) Set on CRC4 multiframe boundaries; will continue to be set  
every 2ms on an arbitrary boundary if CRC4 is disabled.  
Bit 2/Receive Multiframe Event (RMF).  
E1 Mode: Set every 2ms (regardless if CAS signaling is enabled or not) on receive multiframe boundaries. Used to  
alert the host that signaling data is available.  
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.  
Bit 3/Transmit Align Frame Event (TAF). (E1 only) 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 4/Transmit Multiframe Event (TMF).  
E1 Mode: Set every 2ms (regardless if CRC4 is enabled) on transmit multiframe boundaries. Used to alert the host  
that signaling data needs to be updated.  
T1 Mode: Set every 1.5ms on D4 MF boundaries or every 3ms on ESF MF boundaries.  
Bit 5/Receive Signaling All Zeros Event (RSA0). (E1 only) Set when over a full MF, time slot 16 contains all zeros.  
Bit 6/Receive Signaling All Ones Event (RSA1). (E1 only) Set when the contents of time slot 16 contains fewer than three  
zeros over 16 consecutive frames. This alarm is not disabled in the CCS signaling mode.  
Bit 7/Unused.  
61 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
IMR4  
Register Description:  
Register Address:  
Interrupt Mask Register 4  
1Bh  
Bit #  
7
0
6
RSA1  
0
5
RSA0  
0
4
TMF  
0
3
TAF  
0
2
RMF  
0
1
RCMF  
0
0
RAF  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Receive Align Frame Event (RAF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 1/Receive CRC4 Multiframe Event (RCMF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 2/Receive Multiframe Event (RMF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 3/Transmit Align Frame Event (TAF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 4/Transmit Multiframe Event (TMF).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5/Receive Signaling All Zeros Event (RSA0).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 6/Receive Signaling All Ones Event (RSA1).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 7/Unused, must be set = 0 for proper operation.  
62 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TFDL  
Register Description:  
Register Address:  
Transmit FDL Register  
51h  
Bit #  
7
TFDL7  
0
6
TFDL6  
0
5
TFDL5  
0
4
TFDL4  
0
3
TFDL3  
0
2
TFDL2  
0
1
TFDL1  
0
0
TFDL0  
0
Name  
Default  
HW  
0
0
0
1
1
1
0
0
Mode  
Note: Also used to insert Fs framing pattern in D4 framing mode.  
The transmit FDL register (TFDL) contains the FDL information that is to be inserted on a byte-basis into the outgoing T1 data  
stream. The LSB is transmitted first.  
Bit 0/Transmit FDL Bit 0 (TFDL0). LSB of the transmit FDL code.  
Bit 1/Transmit FDL Bit 1 (TFDL1).  
Bit 2/Transmit FDL Bit 2 (TFDL2).  
Bit 3/Transmit FDL Bit 3 (TFDL3).  
Bit 4/Transmit FDL Bit 4 (TFDL4).  
Bit 5/Transmit FDL Bit 5 (TFDL5).  
Bit 6/Transmit FDL Bit 6 (TFDL6).  
Bit 7/Transmit FDL Bit 7 (TFDL7). MSB of the transmit FDL code.  
63 of 123  
DS26503 T1/E1/J1 BITS Element  
12. E1 SYNCHRONIZATION STATUS MESSAGE  
The DS26503 provides access to both the transmit and receive Sa/Si bits. In E1, the Sa bits are used to  
transmit and receive the SSM. The primary method to access the Sa (and Si) bits is based on CRC4  
multiframe access. An alternate method is based on double-frame access.  
Table 12-1. E1 SSM Messages  
QUALITY  
Sa BIT  
MESSAGE  
0000  
DESCRIPTION  
LEVEL  
0
1
Quality unknown (existing sync network)  
Reserved  
0001  
2
Rec. G.811 (Traceable to PRS)  
0010  
3
Reserved  
0011  
4
SSU-A (Traceable to SSU type A, see G.812)  
0100  
5
Reserved  
0101  
6
Reserved  
0110  
7
Reserved  
0111  
8
SSU-B (Traceable to SSU type B, see G.812)  
1000  
9
Reserved  
1001  
10  
11  
12  
13  
14  
15  
Reserved  
1010  
Synchronous Equipment Timing Source  
1011  
Reserved  
1100  
Reserved  
1101  
Reserved  
1110  
Do not use for synchronization  
01111  
In E1 operation, SSMs are transmitted using one of the Sa bits—Sa4, Sa5, Sa6, Sa7, or Sa8. The SSM is  
transmitted MSB first in the first frame of the multiframe. Each multiframe will contain two SSMs, one in  
each sub-multiframe. An SSM is declared valid when the message in three sub-multiframes are alike.  
12.1 Sa/Si Bit Access Based on CRC4 Multiframe  
On the receive side, there is a set of eight registers (RSiAF, RSiNAF, RRA, RSa4 to RSa8) that report the  
Si and Sa bits as they are received. These registers are updated on CRC4 multiframes. A bit in status  
register 4 (SR4.1) indicates the multiframe boundary. The host can use the SR4.1 bit to know when to  
read these registers. The user has 2ms to retrieve the data before it is lost. The MSB of each register is the  
first received. See the following register descriptions for more details.  
On the transmit side, 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 2 (SR4.4).  
The host can use the SR4.4 bit to know when to update these registers. It has 2ms to update the data or  
else the old data will be retransmitted. The MSB of each register is the first bit transmitted. See the  
following register descriptions for details.  
64 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RSiAF  
Register Description:  
Register Address:  
Receive Si Bits of the Align Frame  
58h  
Bit #  
7
SiF0  
0
6
SiF2  
0
5
SiF4  
0
4
SiF6  
0
3
SiF8  
0
2
SiF10  
0
1
0
SiF14  
0
Name  
Default  
HW  
SiF12  
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Si Bit of Frame 14(SiF14).  
Bit 1/Si Bit of Frame 12(SiF12).  
Bit 2/Si Bit of Frame 10(SiF10).  
Bit 3/Si Bit of Frame 8(SiF8).  
Bit 4/Si Bit of Frame 6(SiF6).  
Bit 5/Si Bit of Frame 4(SiF4).  
Bit 6/Si Bit of Frame 2(SiF2).  
Bit 7/Si Bit of Frame 0(SiF0).  
Register Name:  
RSiNAF  
Register Description:  
Register Address:  
Receive Si Bits of the Non-Align Frame  
59h  
Bit #  
7
SiF1  
0
6
SiF3  
0
5
SiF5  
0
4
SiF7  
0
3
SiF9  
0
2
SiF11  
0
1
SiF13  
0
0
SiF15  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Si Bit of Frame 15(SiF15).  
Bit 1/Si Bit of Frame 13(SiF13).  
Bit 2/Si Bit of Frame 11(SiF11).  
Bit 3/Si Bit of Frame 9(SiF9).  
Bit 4/Si Bit of Frame 7(SiF7).  
Bit 5/Si Bit of Frame 5(SiF5).  
Bit 6/Si Bit of Frame 3(SiF3).  
Bit 7/Si Bit of Frame 1(SiF1).  
65 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RRA  
Register Description:  
Register Address:  
Receive Remote Alarm  
5Ah  
Bit #  
7
RRAF1  
0
6
RRAF3  
0
5
RRAF5  
0
4
RRAF7  
0
3
RRAF9  
0
2
1
0
RRAF15  
0
Name  
Default  
HW  
RRAF11 RRAF13  
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Remote Alarm Bit of Frame 15(RRAF15).  
Bit 1/Remote Alarm Bit of Frame 13(RRAF13).  
Bit 2/Remote Alarm Bit of Frame 11(RRAF11).  
Bit 3/Remote Alarm Bit of Frame 9(RRAF9).  
Bit 4/Remote Alarm Bit of Frame 7(RRAF7).  
Bit 5/Remote Alarm Bit of Frame 5(RRAF5).  
Bit 6/Remote Alarm Bit of Frame 3(RRAF3).  
Bit 7/Remote Alarm Bit of Frame 1(RRAF1).  
Register Name:  
RSa4  
Register Description:  
Register Address:  
Receive Sa4 Bits  
5Bh  
Bit #  
7
RSa4F1  
0
6
RSa4F3  
0
5
RSa4F5  
0
4
RSa4F7  
0
3
RSa4F9  
0
2
1
0
Name  
Default  
HW  
RSa4F11 RSa4F13 RSa4F15  
0
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Sa4 Bit of Frame 15(RSa4F15).  
Bit 1/Sa4 Bit of Frame 13(RSa4F13).  
Bit 2/Sa4 Bit of Frame 11(RSa4F11).  
Bit 3/Sa4 Bit of Frame 9(RSa4F9).  
Bit 4/Sa4 Bit of Frame 7(RSa4F7).  
Bit 5/Sa4 Bit of Frame 5(RSa4F5).  
Bit 6/Sa4 Bit of Frame 3(RSa4F3).  
Bit 7/Sa4 Bit of Frame 1(RSa4F1).  
66 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RSa5  
Register Description:  
Register Address:  
Receive Sa5 Bits  
5Ch  
Bit #  
7
RSa5F1  
0
6
RSa5F3  
0
5
RSa5F5  
0
4
RSa5F7  
0
3
RSa5F9  
0
2
1
0
Name  
Default  
HW  
RSa5F11 RSa5F13 RSa5F15  
0
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Sa5 Bit of Frame 15(RSa5F15).  
Bit 1/Sa5 Bit of Frame 13(RSa5F13).  
Bit 2/Sa5 Bit of Frame 11(RSa5F11).  
Bit 3/Sa5 Bit of Frame 9(RSa5F9).  
Bit 4/Sa5 Bit of Frame 7(RSa5F7).  
Bit 5/Sa5 Bit of Frame 5(RSa5F5).  
Bit 6/Sa5 Bit of Frame 3(RSa5F3).  
Bit 7/Sa5 Bit of Frame 1(RSa5F1).  
Register Name:  
RSa6  
Register Description:  
Register Address:  
Receive Sa6 Bits  
5Dh  
Bit #  
7
RSa6F1  
0
6
RSa6F3  
0
5
RSa6F5  
0
4
RSa6F7  
0
3
RSa6F9  
0
2
1
0
Name  
Default  
HW  
RSa6F11 RSa6F13 RSa6F15  
0
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Sa6 Bit of Frame 15(RSa6F15).  
Bit 1/Sa6 Bit of Frame 13(RSa6F13).  
Bit 2/Sa6 Bit of Frame 11(RSa6F11).  
Bit 3/Sa6 Bit of Frame 9(RSa6F9).  
Bit 4/Sa6 Bit of Frame 7(RSa6F7).  
Bit 5/Sa6 Bit of Frame 5(RSa6F5).  
Bit 6/Sa6 Bit of Frame 3(RSa6F3).  
Bit 7/Sa6 Bit of Frame 1(RSa6F1).  
67 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RSa7  
Register Description:  
Register Address:  
Receive Sa7 Bits  
5Eh  
Bit #  
7
RSa7F1  
0
6
RSa7F3  
0
5
RSa7F5  
0
4
RSa7F7  
0
3
RSa7F9  
0
2
1
0
Name  
Default  
HW  
RSa7F11 RSa7F13 RSa7F15  
0
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Sa7 Bit of Frame 15(RSa7F15).  
Bit 1/Sa7 Bit of Frame 13(RSa7F13).  
Bit 2/Sa7 Bit of Frame 11(RSa7F11).  
Bit 3/Sa7 Bit of Frame 9(RSa7F9).  
Bit 4/Sa7 Bit of Frame 7(RSa7F7).  
Bit 5/Sa7 Bit of Frame 5(RSa7F5).  
Bit 6/Sa7 Bit of Frame 3(RSa7F3).  
Bit 7/Sa7 Bit of Frame 1(RSa4F1).  
Register Name:  
RSa8  
Register Description:  
Register Address:  
Receive Sa8 Bits  
5Fh  
Bit #  
7
RSa8F1  
0
6
RSa8F3  
0
5
RSa8F5  
0
4
RSa8F7  
0
3
RSa8F9  
0
2
1
0
Name  
Default  
HW  
RSa8F11 RSa8F13 RSa8F15  
0
0
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Sa8 Bit of Frame 15(RSa8F15).  
Bit 1/Sa8 Bit of Frame 13(RSa8F13).  
Bit 2/Sa8 Bit of Frame 11(RSa8F11).  
Bit 3/Sa8 Bit of Frame 9(RSa8F9).  
Bit 4/Sa8 Bit of Frame 7(RSa8F7).  
Bit 5/Sa8 Bit of Frame 5(RSa8F5).  
Bit 6/Sa8 Bit of Frame 3(RSa8F3).  
Bit 7/Sa8 Bit of Frame 1(RSa8F1).  
68 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TSiAF  
Register Description:  
Register Address:  
Transmit Si Bits of the Align Frame  
42h  
Bit #  
7
TsiF0  
0
6
TsiF2  
0
5
TsiF4  
0
4
TsiF6  
0
3
TsiF8  
0
2
TsiF10  
0
1
0
TsiF14  
0
Name  
Default  
HW  
TsiF12  
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Si Bit of Frame 14(TsiF14).  
Bit 1/Si Bit of Frame 12(TsiF12).  
Bit 2/Si Bit of Frame 10(TsiF10).  
Bit 3/Si Bit of Frame 8(TsiF8).  
Bit 4/Si Bit of Frame 6(TsiF6).  
Bit 5/Si Bit of Frame 4(TsiF4).  
Bit 6/Si Bit of Frame 2(TsiF2).  
Bit 7/Si Bit of Frame 0(TsiF0).  
Register Name:  
TSiNAF  
Register Description:  
Register Address:  
Transmit Si Bits of the Non-Align Frame  
43h  
Bit #  
7
TsiF1  
0
6
TsiF3  
0
5
TsiF5  
0
4
TsiF7  
0
3
TsiF9  
0
2
TsiF11  
0
1
TsiF13  
0
0
TSiF15  
0
Name  
Default  
HW  
0
0
0
0
0
0
0
0
Mode  
Bit 0/Si Bit of Frame 15(TSiF15).  
Bit 1/Si Bit of Frame 13(TsiF13).  
Bit 2/Si Bit of Frame 11(TsiF11).  
Bit 3/Si Bit of Frame 9(TsiF9).  
Bit 4/Si Bit of Frame 7(TsiF7).  
Bit 5/Si Bit of Frame 5(TsiF5).  
Bit 6/Si Bit of Frame 3(TsiF3).  
Bit 7/Si Bit of Frame 1(TsiF1).  
69 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TRA  
Register Description:  
Register Address:  
Transmit Remote Alarm  
44h  
Bit #  
7
TRAF1  
0
6
TRAF3  
0
5
TRAF5  
0
4
TRAF7  
0
3
TRAF9  
0
2
1
0
TRAF15  
0
Name  
Default  
HW  
TRAF11 TRAF13  
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Remote Alarm Bit of Frame 15(TRAF15).  
Bit 1/Remote Alarm Bit of Frame 13(TRAF13).  
Bit 2/Remote Alarm Bit of Frame 11(TRAF11).  
Bit 3/Remote Alarm Bit of Frame 9(TRAF9).  
Bit 4/Remote Alarm Bit of Frame 7(TRAF7).  
Bit 5/Remote Alarm Bit of Frame 5(TRAF5).  
Bit 6/Remote Alarm Bit of Frame 3(TRAF3).  
Bit 7/Remote Alarm Bit of Frame 1(TRAF1).  
Register Name:  
TSa4  
Register Description:  
Register Address:  
Transmit Sa4 Bits  
45h  
Bit #  
7
TSa4F1  
0
6
TSa4F3  
0
5
TSa4F5  
0
4
TSa4F7  
0
3
2
1
0
TSa4F15  
0
Name  
Default  
HW  
TSa4F9 TSa4F11 TSa4F13  
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Sa4 Bit of Frame 15(TSa4F15).  
Bit 1/Sa4 Bit of Frame 13(TSa4F13).  
Bit 2/Sa4 Bit of Frame 11(TSa4F11).  
Bit 3/Sa4 Bit of Frame 9(TSa4F9).  
Bit 4/Sa4 Bit of Frame 7(TSa4F7).  
Bit 5/Sa4 Bit of Frame 5(TSa4F5).  
Bit 6/Sa4 Bit of Frame 3(TSa4F3).  
Bit 7/Sa4 Bit of Frame 1(TSa4F1).  
70 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TSa5  
Register Description:  
Register Address:  
Transmit Sa5 Bits  
46h  
Bit #  
7
TSa5F1  
0
6
TSa5F3  
0
5
TSa5F5  
0
4
TSa5F7  
0
3
2
1
0
TSa5F15  
0
Name  
Default  
HW  
TSa5F9 TSa5F11 TSa5F13  
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Sa5 Bit of Frame 15(TSa5F15).  
Bit 1/Sa5 Bit of Frame 13(TSa5F13).  
Bit 2/Sa5 Bit of Frame 11(TSa5F11).  
Bit 3/Sa5 Bit of Frame 9(TSa5F9).  
Bit 4/Sa5 Bit of Frame 7(TSa5F7).  
Bit 5/Sa5 Bit of Frame 5(TSa5F5).  
Bit 6/Sa5 Bit of Frame 3(TSa5F3).  
Bit 7/Sa5 Bit of Frame 1(TSa5F1).  
Register Name:  
TSa6  
Register Description:  
Register Address:  
Transmit Sa6 Bits  
47h  
Bit #  
7
TSa6F1  
0
6
TSa6F3  
0
5
TSa6F5  
0
4
TSa6F7  
0
3
2
1
0
TSa6F15  
0
Name  
Default  
HW  
TSa6F9 TSa6F11 TSa6F13  
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Sa6 Bit of Frame 15(TSa6F15).  
Bit 1/Sa6 Bit of Frame 13(TSa6F13).  
Bit 2/Sa6 Bit of Frame 11(TSa6F11).  
Bit 3/Sa6 Bit of Frame 9(TSa6F9).  
Bit 4/Sa6 Bit of Frame 7(TSa6F7).  
Bit 5/Sa6 Bit of Frame 5(TSa6F5).  
Bit 6/Sa6 Bit of Frame 3(TSa6F3).  
Bit 7/Sa6 Bit of Frame 1(TSa6F1).  
71 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TSa7  
Register Description:  
Register Address:  
Transmit Sa7 Bits  
48h  
Bit #  
7
TSa7F1  
0
6
TSa7F3  
0
5
TSa7F5  
0
4
TSa7F7  
0
3
2
1
0
TSa7F15  
0
Name  
Default  
HW  
TSa7F9 TSa7F11 TSa7F13  
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Sa7 Bit of Frame 15(TSa7F15).  
Bit 1/Sa7 Bit of Frame 13(TSa7F13).  
Bit 2/Sa7 Bit of Frame 11(TSa7F11).  
Bit 3/Sa7 Bit of Frame 9(TSa7F9).  
Bit 4/Sa7 Bit of Frame 7(TSa7F7).  
Bit 5/Sa7 Bit of Frame 5(TSa7F5).  
Bit 6/Sa7 Bit of Frame 3(TSa7F3).  
Bit 7/Sa7 Bit of Frame 1(TSa4F1).  
Register Name:  
TSa8  
Register Description:  
Register Address:  
Transmit Sa8 Bits  
49h  
Bit #  
7
TSa8F1  
0
6
TSa8F3  
0
5
TSa8F5  
0
4
TSa8F7  
0
3
2
1
0
TSa8F15  
0
Name  
Default  
HW  
TSa8F9 TSa8F11 TSa8F13  
0
0
0
0
0
0
0
0
0
0
0
Mode  
Bit 0/Sa8 Bit of Frame 15(TSa8F15).  
Bit 1/Sa8 Bit of Frame 13(TSa8F13).  
Bit 2/Sa8 Bit of Frame 11(TSa8F11).  
Bit 3/Sa8 Bit of Frame 9(TSa8F9).  
Bit 4/Sa8 Bit of Frame 7(TSa8F7).  
Bit 5/Sa8 Bit of Frame 5(TSa8F5).  
Bit 6/Sa8 Bit of Frame 3(TSa8F3).  
Bit 7/Sa8 Bit of Frame 1(TSa8F1).  
72 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TSACR  
Register Description:  
Register Address:  
Transmit Sa Bit Control Register  
4Ah  
Bit #  
7
SiAF  
0
6
SiNAF  
0
5
RA  
0
4
Sa4  
0
3
Sa5  
0
2
Sa6  
0
1
0
Sa8  
0
Name  
Default  
HW  
Sa7  
0
0
0
0
0
0
0
0
0
Mode  
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  
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 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 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 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 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 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 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  
73 of 123  
DS26503 T1/E1/J1 BITS Element  
12.2 Alternate Sa/Si Bit Access Based on Double-Frame  
On the receive side, 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 status register 4 (SR4.0) will indicate that the contents of the RAF and RNAF  
have been updated. The host can use the SR4.0 bit to know when to read the RAF and RNAF registers.  
The host has 250s to retrieve the data before it is lost.  
On the transmit side, data is sampled from the TAF and TNAF registers with the setting of the transmit  
align frame bit in status register 4 (SR4.3). The host can use the SR4.3 bit to know when to update the  
TAF and TNAF registers. It has 250s to update the data or else the old data will be retransmitted. 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 for the Si bit can come from the Si  
bits of the RAF and TNAF registers, the TSiAF and TSiNAF registers, or passed through from the TSER  
pin.  
Register Name:  
RAF  
Register Description:  
Register Address:  
Receive Align Frame Register  
56h  
Bit #  
7
Si  
0
6
FAS6  
0
5
FAS5  
0
4
FAS4  
0
3
FAS3  
0
2
FAS2  
0
1
FAS1  
0
0
FAS0  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Frame Alignment Signal Bit 0 (FAS0). In normal operation this bit will be = 1.  
Bit 1/Frame Alignment Signal Bit 1 (FAS1). In normal operation this bit will be = 1.  
Bit 2/Frame Alignment Signal Bit 2 (FAS2). In normal operation this bit will be = 0.  
Bit 3/Frame Alignment Signal Bit 3 (FAS3). In normal operation this bit will be = 1.  
Bit 4/Frame Alignment Signal Bit 4 (FAS4). In normal operation this bit will be = 1.  
Bit 5/Frame Alignment Signal Bit 5 (FAS5). In normal operation this bit will be = 0.  
Bit 6/Frame Alignment Signal Bit 6 (FAS6). In normal operation this bit will be = 0.  
Bit 7/International Bit (Si).  
74 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
RNAF  
Register Description:  
Register Address:  
Receive Non-Align Frame Register  
57h  
Bit #  
7
Si  
0
6
1
0
5
A
0
4
Sa4  
0
3
Sa5  
0
2
Sa6  
0
1
0
Sa8  
0
Name  
Default  
HW  
Sa7  
0
X
X
X
X
X
X
X
X
Mode  
Bit 0/Additional Bit 8 (Sa8).  
Bit 1/Additional Bit 7 (Sa7).  
Bit 2/Additional Bit 6 (Sa6).  
Bit 3/Additional Bit 5 (Sa5).  
Bit 4/Additional Bit 4 (Sa4).  
Bit 5 / Remote Alarm (A).  
Bit 6/Frame Nonalignment Signal Bit (1). In normal operation this bit will be = 1.  
Bit 7/International Bit (Si).  
Register Name:  
TAF  
Register Description:  
Register Address:  
Transmit Align Frame Register  
40h  
Bit #  
7
Si  
0
6
0
0
5
0
0
4
1
1
3
1
1
2
0
0
1
1
1
0
1
1
Name  
Default  
HW  
0
0
0
1
1
0
1
1
Mode  
Bit 0/Frame Alignment Signal Bit (1).  
Bit 1/Frame Alignment Signal Bit (1).  
Bit 2/Frame Alignment Signal Bit (0).  
Bit 3/Frame Alignment Signal Bit (1).  
Bit 4/Frame Alignment Signal Bit (1).  
Bit 5/Frame Alignment Signal Bit (0).  
Bit 6/Frame Alignment Signal Bit (0).  
Bit 7/International Bit (Si).  
75 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
TNAF  
Register Description:  
Register Address:  
Transmit Non-Align Frame Register  
41h  
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 0/Additional Bit 8 (Sa8).  
Bit 1/Additional Bit 7 (Sa7).  
Bit 2/Additional Bit 6 (Sa6).  
Bit 3/Additional Bit 5 (Sa5).  
Bit 4/Additional Bit 4 (Sa4).  
Bit 5/Remote Alarm (used to transmit the alarm A).  
Bit 6/Frame Nonalignment Signal Bit (1).  
Bit 7/International Bit (Si).  
76 of 123  
DS26503 T1/E1/J1 BITS Element  
13. LINE INTERFACE UNIT (LIU)  
The LIU in the DS26503 contains three sections: the receiver, which handles clock and data recovery; the  
transmitter, which waveshapes and drives the network line; and the jitter attenuator. These three sections  
are controlled by the line interface control registers (LIC1–LIC4), which are described below.  
The DS26503 can switch between T1 or E1 networks without changing any external components on  
either the transmit or receive side. Figure 13-1 shows a network connection using minimal components.  
In this configuration the DS26503, using a fixed 120external termination, can connect to T1, J1, E1, or  
6312K without any component change. The receiver can adjust the 120termination to 100, 110or  
75. The transmitter can adjust its output impedance to provide high return loss characteristics for 75,  
100, 110, and 120lines. Other components may be added to this configuration to meet safety and  
network protection requirements. This is covered in the Recommended Circuits section.  
Figure 13-1. Basic Network Connection  
TTIP  
10F  
TRANSMIT  
BACKPLANE  
LINE  
CONNECTIONS  
TRING  
2:1  
DS26503  
RTIP  
RECEIVE  
LINE  
RRING  
1:1  
60  
60  
0.01F  
77 of 123  
 
DS26503 T1/E1/J1 BITS Element  
13.1 LIU Operation  
The analog AMI/HDB3 waveform off of the E1 line or the AMI/B8ZS waveform off of the T1 line is  
transformer-coupled into the RTIP and RRING pins of the DS26503. The user has the option to use  
internal termination, software selectable for 75/100/110/120applications, or external termination.  
The LIU recovers clock and data from the analog signal and passes it through the jitter attenuation mux.  
The DS26503 contains an active filter that reconstructs the analog received signal for the nonlinear losses  
that occur in transmission. The receive circuitry also is configurable for various monitor applications. The  
device has a usable receive sensitivity of 0dB to -43dB for E1 and 0dB to -36dB for T1, which allows the  
device to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6000 feet (T1) in length. Data from  
the framer portion of the part is sent via the jitter attenuation MUX to the wave shaping circuitry and line  
driver. The DS26503 will drive the E1 or T1 line from the TTIP and TRING pins via a coupling  
transformer. The line driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or  
short-haul (DSX-1) lines for T1.  
13.2 LIU Receiver  
The DS26503 contains a digital clock recovery system. The DS26503 couples to the receive line via a 1:1  
transformer. The DS26503 has the option of using software-selectable termination requiring only a single,  
fixed pair of termination resistors.  
The DS26503’s LIU is designed to be fully software selectable for E1 and T1 without the need to change  
any external resistors for the receive-side. The receiver will allow the user to configure the DS26503 for  
75, 100, 110, or 120receive termination by setting the RT0(LIC4.0), RT1(LIC4.1), and  
RT2(LIC4.2). When using the internal termination feature, the resistors labeled R in Figure 13-4 should  
be 60each. If external termination is required, RT0, RT1, and RT2 should be set to zero and the  
resistors labeled R in Figure 13-4 will need to be 37.5, 50, 55, or 60each, depending on the line  
impedance.  
There are two ranges of receive sensitivity for both T1 and E1, which is selectable by the user. The EGL  
bit of LIC1 (LIC1.4) selects the full or limited sensitivity.  
The resultant E1 or T1 clock derived from MCLK is multiplied by 16 via an 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 over-sampling technique offers  
outstanding performance to meet jitter tolerance specifications shown in Figure 13-6 and Figure 13-7.  
Normally, the clock that is output at the RCLK pin is the recovered clock from the waveform presented at  
the RTIP and RRING inputs. If the jitter attenuator is placed in the receive path (as is the case in most  
applications), the jitter attenuator restores the RCLK to an approximate 50% duty cycle. If the jitter  
attenuator is either placed in the transmit path or is disabled, the RCLK output can exhibit slightly shorter  
high cycles of the clock. This is due to the highly over-sampled digital clock recovery circuitry. See the  
Receive AC Timing Characteristics section for more details. When no signal is present at RTIP and  
RRING, a receive loss of signal (RLOS) condition will occur and the RCLK will be derived from the  
JACLK source.  
13.2.1 Receive Level Indicator  
The DS26503 will report the signal strength at RTIP and RRING in 2.5dB increments via RL3-RL0  
located in the Information Register 1 (INFO1). This feature is helpful when trouble shooting line  
performance problems.  
78 of 123  
DS26503 T1/E1/J1 BITS Element  
13.2.2 Receive G.703 Section 10 Synchronization Signal  
The DS26503 can receive a 2.048MHz square-wave synchronization clock as specified in Section 10 of  
ITU G.703. To use the DS26503 in this mode, set the mode configuration bits in the Mode Configuration  
Register (MCREG).  
13.2.3 Monitor Mode  
Monitor applications in both E1 and T1 require various flat gain settings for the receive-side circuitry.  
The DS26503 can be programmed to support these applications via the monitor mode control bits MM1  
and MM0 in the LIC3 register.  
Figure 13-2. Typical Monitor Application  
PRIMARY  
T1/E1 LINE  
Rm  
T1/E1 TERMINATING  
DEVICE  
Rm  
X
F
DS26503  
Rt  
M
R
MONITOR  
PORT JACK  
SECONDARY T1/E1  
TERMINATING  
DEVICE  
13.3 LIU Transmitter  
The DS26503 uses a phase-lock loop along with a precision digital-to-analog converter (DAC) to create  
the waveforms that are transmitted onto the E1 or T1 line. The waveforms created by the DS26503 meet  
the latest ETSI, ITU, ANSI, and AT&T specifications. The waveform that is to be generated is set by the  
transmit mode bits (TMODE[3:0]) in the MCREG register, as well as the L2/L1/L0 bits in register LIC1  
if applicable.  
ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs  
require an accuracy of ±32ppm for T1 interfaces. The transmit clock can be sourced from the recovered  
clock (RCLK), the pre-scaled MCLK, the TCLK pin or the TX PLL. See the TX PLL clock mux diagram  
in Figure 3-3. Due to the nature of the design of the transmitter in the DS26503, very little jitter (less than  
0.005 UIP-P broadband from 10Hz to 100kHz) is added to the jitter present on the selected transmit clock  
source. Also, the waveforms created are independent of the duty cycle of TCLK. The transmitter in the  
DS26503 couples to the transmit twisted pair (or coaxial cable in some applications) via a 1:2 step-up  
transformer. For the device to create the proper waveforms, the transformer used must meet the  
specifications listed in Table 13-1. The DS26503 has the option of using software-selectable transmit  
termination.  
79 of 123  
DS26503 T1/E1/J1 BITS Element  
The transmit line drive has two modes of operation: fixed gain or automatic gain. In the fixed gain mode,  
the transmitter outputs a fixed current into the network load to achieve a nominal pulse amplitude. In the  
automatic gain mode, the transmitter adjusts its output level to compensate for slight variances in the  
network load. See the Transmit Line Build-Out Control (TLBC) register for details.  
13.3.1 Transmit Short-Circuit Detector/Limiter  
The DS26503 has an automatic short-circuit limiter that limits the source current to 50mA (rms) into a  
1load. This feature can be disabled by setting the SCLD bit (LIC2.1) = 1. TCLE (SR1.2) provides a  
real-time indication of when the current limiter is activated. If the current limiter is disabled, TCLE will  
indicate that a short-circuit condition exist. Status Register SR1.2 provides a latched version of the  
information, which can be used to activate an interrupt when enable via the IMR1 register. When set low,  
the TPD bit (LIC1.0) will power-down the transmit line driver and tri-state the TTIP and TRING pins.  
13.3.2 Transmit Open-Circuit Detector  
The DS26503 can also detect when the TTIP or TRING outputs are open circuited. TOCD (SR1.1) will  
provide a real-time indication of when an open circuit is detected. SR1 provides a latched version of the  
information (SR1.1), which can be used to activate an interrupt when enable via the IMR1 register.  
13.3.3 Transmit BPV Error Insertion  
When IBPV (LIC2.5) is transitioned from a zero to a one, the device waits for the next occurrence of  
three consecutive ones to insert a BPV. IBPV must be cleared and set again for another BPV error  
insertion.  
13.3.4 Transmit G.703 Section 10 Synchronization Signal (E1 Mode)  
The DS26503 can transmit the 2.048MHz square-wave synchronization clock. To transmit the 2.048MHz  
clock, when in E1 mode, set the mode configuration bits in the Mode Configuration Register (MCREG).  
13.4 MCLK Pre-Scaler  
A 16.384MHz, 8.192MHz, 4.096MHz, 2.048MHz, or 1.544MHz clock must be applied at MCLK. ITU  
specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require  
an accuracy of ±32ppm for T1 interfaces. A prescaler will divide the 16MHz, 8MHz, or 4MHz clock down to  
2.048MHz. There is a PLL for the jitter attenuator that will convert the 2.048MHz clock to a 1.544MHz rate  
for T1 applications. Setting JACKS (LIC2.3) to a logic 0 bypasses this PLL.  
13.5 Jitter Attenuator  
The DS26503’s jitter attenuator can be set to a depth of either 32 bits or 128 bits via the JABDS bit  
(LIC1.2). 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 13-10 and Figure 13-11. The jitter attenuator can be placed in either the receive path or the  
transmit path by appropriately setting or clearing the JAS bit (LIC1.3). If the part is configured for  
hardware mode and the jitter attenuator is enabled, it will automatically be placed in the receive path. The  
jitter attenuator can also be disabled (in effect, removed) by setting the DJA bit (LIC1.1). Either the  
recovered clock from the clock/data recovery block or the clock applied at the TCLK pin is adjusted to  
create a smooth jitter-free clock that 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 DS26503 will divide the internal nominal 32.768MHz (E1) or 24.704MHz (T1) clock by either  
80 of 123  
DS26503 T1/E1/J1 BITS Element  
15 or 17 instead of the normal 16 to keep the buffer from overflowing. When the device divides by either  
15 or 17, it also sets the Jitter Attenuator Limit Trip (JALT) bit in Status Register 1 (SR1.4).  
13.6 CMI (Code Mark Inversion) Option  
The DS26503 provides a CMI interface for connection to optical transports. This interface is a unipolar  
1T2B type of signal. Ones are encoded as either a logical one or zero level for the full duration of the  
clock period. Zeros are encoded as a zero-to-one transition at the middle of the clock period.  
Figure 13-3. CMI Coding  
CLOCK  
1
1
0
1
0
0
1
DATA  
CMI  
Transmit and receive CMI is enabled via LIC4.7. When this register bit is set, the TTIP pin will output  
CMI-coded data at normal levels. This signal can be used to directly drive an optical interface. When  
CMI is enabled, the user can also use HDB3/B8ZS coding. When this register bit is set, the RTIP pin will  
become a unipolar CMI input. The CMI signal will be processed to extract and align the clock with data.  
81 of 123  
DS26503 T1/E1/J1 BITS Element  
13.7 LIU Control Registers  
Register Name:  
LIC1  
Register Description:  
Register Address:  
Line Interface Control 1  
30h  
Bit #  
7
L2  
6
L1  
5
L0  
4
EGL  
0
3
JAS  
0
2
JABDS  
0
1
0
TPD  
0
Name  
Default  
HW  
DJA  
0
0
0
0
L2  
L1  
L0  
0
0
0
0
1
Mode  
PIN 13  
PIN 12  
PIN 11  
Bit 0/Transmit Power-Down (TPD).  
0 = powers down the transmitter and tri-states the TTIP and TRING pins  
1 = normal transmitter operation  
Bit 1/Disable Jitter Attenuator (DJA).  
0 = jitter attenuator enabled  
1 = jitter attenuator disabled  
Bit 2/Jitter Attenuator Buffer Depth Select (JABDS).  
0 = 128 bits  
1 = 32 bits (use for delay-sensitive applications)  
Bit 3/Jitter Attenuator Select (JAS).  
0 = place the jitter attenuator on the receive side  
1 = place the jitter attenuator on the transmit side  
Bit 4/Receive Equalizer Gain Limit (EGL). This bit controls the sensitivity of the receive equalizer.  
T1 Mode: 0 = -36dB (long haul)  
1 = -15dB (limited long haul)  
E1 Mode: 0 = -43dB (long haul)  
1 = -12dB (short haul)  
Bits 5-7/Line Build-Out Select (L0 to L2). When using the internal termination, the user needs only to select 000 for 75  
operation or 001 for 120operation. This selects the proper voltage levels for 75or 120operation. Using TT0 and TT1 of  
the LICR4 register, users can then select the proper internal source termination. Line build-outs 100 and 101 are for backwards  
compatibility with older products only.  
E1 Mode  
L2  
0
L1  
0
L0  
0
APPLICATION  
N (1)  
1:2  
RETURN LOSS  
N.M.  
Rt (1)  
0
75normal  
0
0
1
120normal  
75with high return loss*  
120with high return loss*  
1:2  
N.M.  
0
1
0
0
0
1
1:2  
1:2  
21dB  
21dB  
6.2Ω  
11.6Ω  
1
*TT0 and TT1 of LIC4 register must be set to zero in this configuration.  
82 of 123  
DS26503 T1/E1/J1 BITS Element  
T1 Mode  
L2  
0
L1  
L0  
0
APPLICATION  
DSX-1 (0 to 133 feet)/0dB CSU  
DSX-1 (133 to 266 feet)  
DSX-1 (266 to 399 feet)  
DSX-1 (399 to 533 feet)  
DSX-1 (533 to 655 feet)  
Reserved  
N (1)  
1:2  
RETURN LOSS  
N.M.  
Rt (1)  
0
0
1
1
0
0
1
1
0
0
0
0
0
0
1
1:2  
N.M.  
0
0
1:2  
N.M.  
0
1
1:2  
N.M.  
1
0
1:2  
N.M.  
1
1
1
0
Reserved  
1
1
Reserved  
Register Name:  
TLBC  
Register Description:  
Register Address:  
Transmit Line Build-Out Control  
34h  
Bit #  
7
0
6
AGCE  
0
5
GC5  
0
4
GC4  
0
3
GC3  
0
2
1
0
GC0  
0
Name  
Default  
HW  
GC2  
0
GC1  
0
0
0
0
0
0
0
0
0
Mode  
Bit 0–5/Gain Control Bits 0–5 (GC0–GC5). The GC0 through GC5 bits control the gain setting for the non-automatic gain  
mode. Use the tables below for setting the recommended values. The LB (line build-out) column refers to the value in the  
L0–L2 bits in LIC1 (Line Interface Control 1) register.  
NETWORK MODE  
LB  
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
4
5
0
1
GC5  
1
GC4  
0
GC3  
0
GC2  
1
GC1  
1
GC0  
0
0
1
1
0
1
1
0
1
1
0
1
0
1
0
0
0
0
0
T1, Impedance Match Off  
1
0
0
1
1
1
1
0
0
1
1
1
0
1
0
0
1
1
1
1
1
1
1
1
0
1
1
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
1
0
T1, Impedance Match On  
1
0
0
0
1
0
1
0
0
0
0
0
0
0
1
1
0
0
1
1
1
1
1
1
1
0
0
0
0
1
1
0
0
0
0
1
E1, Impedance Match Off  
E1, Impedance Match On  
1
0
1
0
1
0
1
0
1
0
0
0
0
1
1
0
1
0
0
1
1
0
1
0
Bit 6/Automatic Gain Control Enable (AGCE).  
0 = use Transmit AGC, TLBC bits 0–5 are “don’t care”  
1 = do not use Transmit AGC, TLBC bits 0–5 set nominal level  
Bit 7/Unused, must be set = 0 for proper operation.  
83 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
LIC2  
Register Description:  
Register Address:  
Line Interface Control 2  
31h  
Bit #  
7
0
6
LIRST  
0
5
IBPV  
0
4
3
2
0
1
SCLD  
0
0
CLDS  
0
Name  
Default  
HW  
TAIS  
0
JACKS  
0
TAIS  
PIN 10  
JACKS  
PIN 46  
0
0
0
0
0
0
Mode  
Bit 0/Custom Line Driver Select (CLDS). Setting this bit to a one will redefine the operation of the transmit line driver.  
When this bit is set to a one and LIC1.5 = LIC1.6 = LIC1.7 = 0, then the device will generate a square wave at the TTIP and  
TRING outputs instead of a normal waveform. When this bit is set to a one and LIC1.5 = LIC1.6 = LIC1.7 U 0, then the device  
will force TTIP and TRING outputs to become open-drain drivers instead of their normal push-pull operation. This bit should  
be set to zero for normal operation of the device.  
Bit 1/Short Circuit Limit Disable (in E1 mode) (SCLD). Controls the 50mA (rms) current limiter.  
0 = enable 50mA current limiter  
1 = disable 50mA current limiter  
Bit 2/Unused, must be set = 0 for proper operation.  
Bit 3/Jitter Attenuator Mux (JACKS). Controls the source for JA CLOCK. This bit is only used in T1 mode.  
0 = JA CLOCK sourced from the pre-scaled MCLK  
1 = JA CLOCK sourced from internal PLL  
Bit 4/Transmit Alarm Indication Signal (TAIS).  
0 = transmit an unframed all-ones code  
1 = transmit data normally  
Bit 5/Insert BPV (IBPV). A zero-to-one transition on this bit will cause a single BPV to be inserted into the transmit data  
stream. Once this bit has been toggled from a zero to a one, 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 6/Line Interface Reset (LIRST). Setting this bit from a zero to a one will initiate an internal reset that resets the clock  
recovery state machine and recenters the jitter attenuator. Normally this bit is only toggled on power-up. Must be cleared and  
set again for a subsequent reset.  
Bit 7/Unused, must be set = 0 for proper operation.  
84 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
LIC3  
Register Description:  
Register Address:  
Line Interface Control 3  
32h  
Bit #  
7
CMIE  
0
6
CMII  
0
5
0
4
MM1  
0
3
MM0  
0
2
0
1
0
0
TAOZ  
0
Name  
Default  
HW  
0
0
0
0
0
0
0
0
Mode  
Bit 0/Transmit Alternate Ones and Zeros (TAOZ). Transmit a …101010… pattern at TTIP and TRING.  
0 = disabled  
1 = enabled  
Bit 1/Unused, must be set = 0 for proper operation.  
Bit 2/Unused, must be set = 0 for proper operation.  
Bits 3-4/Monitor Mode (MM0 to MM1).  
MM1  
MM0  
INTERNAL LINEAR GAIN BOOST (dB)  
0
0
1
1
0
1
0
1
Normal operation (no boost)  
20  
26  
32  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/CMI Invert (CMII).  
0 = CMI normal at TTIP and RTIP  
1 = invert CMI signal at TTIP and RTIP  
Bit 7/CMI Enable (CMIE).  
0 = disable CMI mode  
1 = enable CMI mode  
85 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
LIC4  
Register Description:  
Register Address:  
Line Interface Control 4  
33h  
Bit #  
7
6
5
TT2  
0
4
TT1  
0
3
TT0  
0
2
RT2  
0
1
RT1  
0
0
RT0  
0
Name  
Default  
HW  
MPS1  
0
MPS0  
0
MPS1  
PIN 16  
MPS0  
PIN 15  
Mode  
Bits 0-2/Receive Termination Select (RT0 to RT1).  
INTERNAL RECEIVE  
RT2  
RT1  
RT0  
TERMINATION CONFIGURATION  
Internal Receive-Side Termination Disabled  
Internal Receive-Side 75Enabled  
0
0
0
0
1
0
0
1
1
0
0
1
0
1
0
Internal Receive-Side 100Enabled  
Internal Receive-Side 120Enabled  
Internal Receive-Side 110Enabled  
Internal Receive-Side Termination Disabled  
Internal Receive-Side Termination Disabled  
Internal Receive-Side Termination Disabled  
1
1
1
0
1
1
1
0
1
Bits 3-5/Transmit Termination Select (TT0 to TT1).  
INTERNAL TRANSMIT  
TT2  
TT1  
TT0  
TERMINATION CONFIGURATION  
Internal Transmit-Side Termination Disabled  
Internal Transmit-Side 75Enabled  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Internal Transmit-Side 100Enabled  
Internal Transmit-Side 120Enabled  
Internal Transmit-Side 110Enabled  
Internal Transmit-Side Termination Disabled  
Internal Transmit-Side Termination Disabled  
Internal Transmit-Side Termination Disabled  
Bits 6-7/MCLK Prescaler (MPS0 to MPS1). T1 Mode  
MCLK (MHz)  
1.544  
MPS1  
MPS0  
JACKS (LIC2.3)  
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
3.088  
6.176  
12.352  
2.048  
4.096  
8.192  
16.384  
Bits 6-7/MCLK Prescaler (MPS0 to MPS1). E1 Mode  
MCLK (MHz)  
2.048  
MPS1  
MPS0  
JACKS (LIC2.3)  
0
0
1
1
0
1
0
1
0
0
0
0
4.096  
8.192  
16.384  
86 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
INFO1  
Register Description:  
Register Address:  
Information Register 1  
11h  
Bit #  
7
0
6
0
5
0
4
0
3
RL3  
0
2
RL2  
0
1
RL1  
0
0
RL0  
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bits 0-3/Receive Level Bits (RL0 to RL3). Real-time bits  
RL3  
0
RL2  
0
RL1  
0
RL0  
0
RECEIVE LEVEL (dB)  
Greater than -2.5  
-2.5 to -5.0  
0
0
0
1
0
0
1
0
-5.0 to -7.5  
0
0
1
1
-7.5 to -10.0  
0
1
0
0
-10.0 to -12.5  
-12.5 to -15.0  
-15.0 to -17.5  
-17.5 to -20.0  
-20.0 to -22.5  
-22.5 to -25.0  
-25.0 to -27.5  
-27.5 to -30.0  
-30.0 to –32.5  
-32.5 to -35.0  
-35.0 to -37.5  
Less than -37.5  
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
Bit 4/Unused.  
Bit 5/Unused.  
Bit 6/Unused.  
Bit 7/Unused.  
87 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
SR1  
Register Description:  
Register Address:  
Status Register 1  
14h  
Bit #  
7
0
6
0
5
0
4
JALT  
0
3
0
2
TCLE  
0
1
TOCD  
0
0
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/Unused, must be set = 0 for proper operation.  
Bit 1/Transmit Open Circuit Detect Condition (TOCD). Set when the device detects that the TTIP and TRING outputs are  
open-circuited.  
Bit 2/Transmit Current Limit Exceeded Condition (TCLE). Set when the 50mA (rms) current limiter is activated whether  
the current limiter is enabled or not.  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/Jitter Attenuator Limit Trip Event (JALT). Set when the jitter attenuator FIFO reaches to within 4 bits of its useful  
limit. Will be cleared when read. Useful for debugging jitter-attenuation operation.  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
88 of 123  
DS26503 T1/E1/J1 BITS Element  
Register Name:  
IMR1  
Register Description:  
Register Address:  
Interrupt Mask Register 1  
15h  
Bit #  
7
0
6
0
5
0
4
JALT  
0
3
0
2
TCLE  
0
1
TOCD  
0
0
0
Name  
Default  
HW  
X
X
X
X
X
X
X
X
Mode  
Bit 0/ Unused, must be set = 0 for proper operation.  
Bit 1/Transmit Open Circuit Detect Condition (TOCD).  
0 = interrupt masked  
1 = interrupt enabled–generates interrupts on rising and falling edges  
Bit 2/Transmit Current Limit Exceeded Condition (TCLE).  
0 = interrupt masked  
1 = interrupt enabled–generates interrupts on rising and falling edges  
Bit 3/Unused, must be set = 0 for proper operation.  
Bit 4/Jitter Attenuator Limit Trip Event (JALT).  
0 = interrupt masked  
1 = interrupt enabled  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
89 of 123  
DS26503 T1/E1/J1 BITS Element  
13.8 Recommended Circuits  
Figure 13-4. Basic Interface  
VDD  
DS26503  
2:1  
0.1F 0.01F  
TTIP  
DVDD  
TRANSMIT  
LINE  
C
DVSS  
0.1F  
10F  
TRING  
TVDD  
TVSS  
+
0.1F 10F  
RVDD  
RVSS  
1:1  
+
RTIP  
RECEIVE  
LINE  
RRING  
R
R
0.1F  
NOTES:  
1) All resistor values are ±1%.  
2) Resistors R should be set to 60each if the internal receive-side termination feature  
is enabled. When this feature is disabled,  
R = 37.5for 75coaxial E1 lines; 60for 120twisted pair E1 lines; or 50for  
100twisted pair T1 lines.  
3) C = 10F ceramic.  
90 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 13-5. Protected Interface Using Internal Receive Termination  
VDD  
VDD  
D1 D2  
DS26503  
2:1  
0.1F 0.01F  
TTIP  
DVDD  
F1  
F2  
C1  
0.1F  
TRANSMIT  
LINE  
S1  
DVSS  
68F  
D4  
0.1F  
10F  
+
TRING  
TVDD  
TVSS  
X2  
D3  
+
0.1F 10F  
VDD  
RVDD  
RVSS  
+
D5 D6  
1:1  
RTIP  
S2  
F3  
F4  
RECEIVE  
LINE  
0.1F  
D8  
RRING  
X1  
D7  
60  
60  
0.1F  
NOTES:  
1) All resistor values are ±1%.  
2) X1 and X2 are very low DCR transformers  
3) C1 = 10F ceramic.  
4) S1 and S2 are 6V transient suppressers.  
5) D1 to D8 are Schottky diodes.  
6) The fuses, F1–F4, are optional to prevent AC power-line crosses from compromising the  
transformers.  
7) The 68F is used to keep the local power-plane potential within tolerance during a surge.  
91 of 123  
DS26503 T1/E1/J1 BITS Element  
13.9 Component Specifications  
Table 13-1. Transformer Specifications  
SPECIFICATION  
RECOMMENDED VALUE  
Turns Ratio 3.3V Applications  
1:1 (receive) and 1:2 (transmit) ±2%  
600H minimum  
Primary Inductance  
Leakage Inductance  
1.0H maximum  
40pF maximum  
Intertwining Capacitance  
Transmit Transformer DC Resistance  
Primary (Device Side)  
Secondary  
1.0maximum  
2.0maximum  
Receive Transformer DC Resistance  
Primary (Device Side)  
Secondary  
1.2maximum  
1.2maximum  
92 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 13-6. E1 Transmit Pulse Template  
1.2  
1.1  
1.0  
0.9  
0.8  
0.7  
269ns  
G.703  
Template  
194ns  
0.6  
0.5  
219ns  
0.4  
0.3  
0.2  
0.1  
0
-0.1  
-0.2  
-250  
-200  
-150  
-100  
-50  
0
50  
100  
150  
200  
250  
TIME (ns)  
Figure 13-7. T1 Transmit Pulse Template  
1.2  
1.1  
1.0  
0.9  
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
MAXIMUM CURVE  
UI Time Amp.  
MINIMUM CURVE  
UI Time Amp.  
-0.77 -500 0.05  
-0.39 -255 0.05  
-0.27 -175 0.80  
-0.27 -175 1.15  
-0.77 -500 -0.05  
-0.23 -150 -0.05  
-0.23 -150 0.50  
-0.15 -100 0.95  
-0.12 -75  
1.15  
1.05  
1.05  
-0.07  
0.05  
0.05  
0.00  
0
0.95  
0.00  
0
0.15 100  
0.23 150  
0.23 150  
0.46 300  
0.66 430  
0.93 600  
1.16 750  
0.90  
0.27 175  
0.35 225  
0.93 600  
1.16 750  
0.50  
-0.45  
-0.45  
-0.20  
-0.05  
-0.05  
-0.1  
T1.102/87, T1.403,  
-0.2  
-0.3  
-0.4  
-0.5  
CB 119 (Oct. 79), &  
I.431 Template  
-500 -400 -300 -200 -100  
0
100 200 300 400 500 600 700  
TIME (ns)  
93 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 13-8. Jitter Tolerance (T1 Mode)  
1K  
DS26503  
Tolerance  
100  
TR 62411 (Dec. 90)  
ITU-T G.823  
10  
1
0.1  
1
10  
100  
1K  
10K  
100K  
FREQUENCY (Hz)  
Figure 13-9. Jitter Tolerance (E1 Mode)  
1k  
DS26503  
Tolerance  
100  
40  
10  
1.5  
1
Minimum Tolerance  
Level as per  
0.2  
ITU G.823  
0.1  
2.4k  
20  
18k  
1
10  
100  
1k  
10k  
100k  
FREQUENCY (Hz)  
94 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 13-10. Jitter Attenuation (T1 Mode)  
0
-20  
Curve A  
TR 62411 (Dec. 90)  
Prohibited Area  
Curve B  
-40  
DS26503  
T1 MODE  
-60  
1
10  
100  
1K  
10K  
100K  
FREQUENCY (Hz)  
Figure 13-11. Jitter Attenuation (E1 Mode)  
0
ITU G.7XX  
Prohibited Area  
TBR12  
Prohibited  
Area  
-20  
DS26503  
-40  
E1 MODE  
-60  
1
10  
100  
1K  
10K  
100K  
FREQUENCY (Hz)  
95 of 123  
DS26503 T1/E1/J1 BITS Element  
14. LOOPBACK CONFIGURATION  
Register Name:  
LBCR  
Register Description:  
Register Address:  
Loopback Control Register  
20h  
Bit #  
7
0
6
0
5
0
4
0
3
LLB  
0
2
RLB  
0
RLB  
PIN 60  
1
0
0
0
Name  
Default  
HW  
0
0
0
0
0
0
0
Mode  
Bit 0/Unused, must be set = 0 for proper operation.  
Bit 1/Unused, must be set = 0 for proper operation.  
Bit 2/ Remote Loopback (RLB). In this loopback, data received at RTIP and RRING will be looped back to the transmit LIU.  
Received data will continue to pass through the receive side framer of the DS26503 as it would normally and the data from the  
transmit side formatter will be ignored.  
0 = loopback disabled  
1 = loopback enabled  
Bit 3/Local Loopback (LLB). In this loopback, data will continue to be transmitted as normal through the transmit side of the  
DS26503. Data being received at RTIP and RRING will be replaced with the data being transmitted. Data in this loopback will  
pass through the jitter attenuator if enabled.  
0 = loopback disabled  
1 = loopback enabled  
Bit 4/Unused, must be set = 0 for proper operation.  
Bit 5/Unused, must be set = 0 for proper operation.  
Bit 6/Unused, must be set = 0 for proper operation.  
Bit 7/Unused, must be set = 0 for proper operation.  
96 of 123  
DS26503 T1/E1/J1 BITS Element  
15. 6312kHz SYNCHRONIZATION INTERFACE  
The DS26503 has a 6312kHz Synchronization Interface mode of operation that conforms with Appendix  
II.2 of G.703, with the exception that the DS26503 transmits a square wave as opposed to the sine wave  
that is defined in the G.703 specification.  
15.1 Receive 6312kHz Synchronization Interface Operation  
On the receive interface, a 6312kHz sine wave is accepted conforming to the input port requirements of  
G.703 Appendix II. Alternatively, a 6312kHz square wave will also be accepted. A 6312kHz square wave  
is output on RCLK in the receive direction. RS is not driven in this mode and will be tri-stated.  
Table 15-1. Specification of 6312kHz Clock  
Signal at Input Port  
Frequency  
6312kHz  
Signal format  
Alarm condition  
Sinusoidal wave  
Alarm should not be occurred against  
the amplitude ranged  
-16dBm to +3dBm  
15.2 Transmit 6312kHz Synchronization Interface Operation  
On the transmit interface, a nominally 50% duty cycle, 6312kHz square wave at standard logic levels is  
available from the PLL_OUT pin. In normal operation, the TCLKO pin will output the same signal.  
However, if remote loopback is enabled then TCLKO will be replaced with the recovered receive clock.  
See Figure 3-1. The G.703 requirements for the 6312kHz transmitted signal are shown in Table 15-2. The  
user must provide an external circuit to convert the TCLKO or PLL_OUT signal to the level and  
impedance required by G.703. The RSER and TS pins are ignored in this mode. TTIP and TRING will  
be tri-stated in this mode.  
Table 15-2. Specification of 6312kHz Clock  
Signal at Output Port  
Frequency  
6312kHz  
Load impedance  
Transmission media  
Amplitude  
75resistive  
Coaxial pair cable  
0dBm M 3dBm  
97 of 123  
 
DS26503 T1/E1/J1 BITS Element  
16. JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT  
The DS26503 supports the standard IEEE 1149.1 instruction codes SAMPLE/PRELOAD, BYPASS, and  
EXTEST. Optional public instructions included are HIGHZ, CLAMP, and IDCODE. The DS26503  
contains the following as required by IEEE 1149.1 Standard Test Access Port and Boundary Scan  
Architecture:  
CꢀTest Access Port (TAP)  
CꢀTAP Controller  
CꢀInstruction Register  
CꢀBypass Register  
CꢀBoundary Scan Register  
CꢀDevice Identification Register  
Details on Boundary Scan Architecture and the Test Access Port can be found in IEEE 1149.1-1990,  
IEEE 1149.1a-1993, and IEEE 1149.1b-1994.  
The Test Access Port has the necessary interface pins: JTRST, JTCLK, JTMS, JTDI, and JTDO. See the  
pin descriptions for details.  
Figure 16-1. JTAG Functional Block Diagram  
BOUNDRY SCAN  
REGISTER  
IDENTIFICATION  
REGISTER  
MUX  
BYPASS  
REGISTER  
INSTRUCTION  
REGISTER  
TEST ACCESS PORT  
CONTROLLER  
SELECT  
OUTPUT ENABLE  
VDD  
VDD  
VDD  
10kꢁ  
10kꢁ  
10kꢁ  
JTDI  
JTMS  
JTCLK  
JTDO  
JTRST  
98 of 123  
DS26503 T1/E1/J1 BITS Element  
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 16-2.  
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 can 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 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 toward 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.  
99 of 123  
DS26503 T1/E1/J1 BITS Element  
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 toward the serial output. The parallel register as well as 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.  
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, will put the controller in the run-test-idle  
state. With JTMS HIGH, the controller will enter the select-DR-scan state.  
100 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 16-2. TAP Controller State Diagram  
Test Logic  
1
Reset  
0
1
1
1
Run Test/  
Select  
Select  
0
Idle  
DR-Scan  
IR-Scan  
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
101 of 123  
DS26503 T1/E1/J1 BITS Element  
16.1 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 toward 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.  
Table 16-1. Instruction Codes for IEEE 1149.1 Architecture  
INSTRUCTION  
SELECTED REGISTER  
INSTRUCTION CODES  
SAMPLE/PRELOAD  
Boundary Scan  
010  
111  
000  
011  
100  
001  
BYPASS  
Bypass  
EXTEST  
Boundary Scan  
Bypass  
CLAMP  
HIGHZ  
Bypass  
IDCODE  
Device Identification  
SAMPLE/PRELOAD  
This is a mandatory instruction for the IEEE 1149.1 specification that 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.  
102 of 123  
DS26503 T1/E1/J1 BITS Element  
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 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 16-2. Table 16-3 lists the device ID codes.  
Table 16-2. ID Code Structure  
MSB  
LSB  
Version  
Device ID  
16 bits  
JEDEC  
1
1
Contact Factory  
4 bits  
00010100001  
Table 16-3. Device ID Codes  
DEVICE  
DS26503  
16-BIT ID  
0035h  
16.2 Test Registers  
IEEE 1149.1 requires a minimum of two test registers: the bypass register and the boundary scan register.  
An optional test register has been included with the DS26503 design. This test register is the  
identification register and is used with the IDCODE instruction and the test-logic-reset state of the TAP  
controller.  
16.3 Boundary Scan Register  
This register contains both a shift register path and a latched parallel output for all control cells and  
digital I/O cells and is n bits in length. See for all the cell bit locations and definitions.  
16.4 Bypass Register  
This is a single 1-bit shift register used with the BYPASS, CLAMP, and HIGHZ instructions that  
provides a short path between JTDI and JTDO.  
16.5 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.  
103 of 123  
 
 
DS26503 T1/E1/J1 BITS Element  
Table 16-4. Boundary Scan Control Bits  
CONTROL  
CELL #  
NAME  
TYPE  
CELL  
0
AD1  
AD1_7_CTRL  
AD0  
Output3  
1
3
1
Controlr  
2
Output3  
3
AD0_CTRL  
WR_RW  
RD_DS  
CS  
Controlr  
4
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
Output3  
5
6
7
BIS1  
8
BIS0  
9
BTS  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
THZE  
TMODE1  
TMODE2  
PLL_CLK  
INT  
15  
INT_CTRL  
TSTRST  
RLOS  
Controlr  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
Output3  
TCSS1  
RLOF  
RAIS  
RSER  
OUT_400HZ*  
RS  
RCLK  
TS  
26  
TS_CTRL  
TSER  
Controlr  
observe_only  
104 of 123  
DS26503 T1/E1/J1 BITS Element  
CONTROL  
CELL  
CELL #  
NAME  
TYPE  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
TPOSO  
TNEGO  
TCLKO  
TCLK  
ALE_A7  
A6  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
observe_only  
Output3  
A5  
A4  
A3  
A2  
A1  
A0  
AD7  
AD6  
AD5  
AD4  
AD3  
AD2  
1
1
1
1
1
1
Output3  
Output3  
Output3  
Output3  
Output3  
* This pin is not bonded out on the DS26503 package, however, it must be  
accounted for in the chain.  
105 of 123  
DS26503 T1/E1/J1 BITS Element  
17. FUNCTIONAL TIMING DIAGRAMS  
17.1 Processor Interface  
17.1.1 Parallel Port Mode  
See the AC Timing section.  
17.1.2 SPI Serial Port Mode  
Figure 17-1. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 0  
SCK  
CS  
1
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
B
MOSI  
MISO  
MSB  
LSB  
MSB  
LSB  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
MSB  
LSB  
Figure 17-2. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 0  
SCK  
CS  
1
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
B
MOSI  
MISO  
MSB  
LSB  
MSB  
LSB  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
LSB  
MSB  
Figure 17-3. SPI Serial Port Access, Read Mode, CPOL = 0, CPHA = 1  
SCK  
CS  
1
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
B
MOSI  
MISO  
MSB  
LSB MSB  
LSB  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
LSB  
MSB  
106 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 17-4. SPI Serial Port Access, Read Mode, CPOL = 1, CPHA = 1  
SCK  
CS  
A7  
LSB MSB  
1
0
0
0
0
0
0
A6  
A5  
A4  
A3  
A2  
A1  
A0  
B
MOSI  
MISO  
MSB  
LSB  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
MSB  
LSB  
Figure 17-5. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 0  
SCK  
CS  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
B
0
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
MOSI  
MISO  
MSB  
LSB  
MSB  
LSB  
MSB  
LSB  
Figure 17-6. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 0  
SCK  
CS  
D7  
LSB MSB  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
B
0
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
MOSI  
MISO  
MSB  
LSB MSB  
LSB  
107 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 17-7. SPI Serial Port Access, Write Mode, CPOL = 0, CPHA = 1  
SCK  
CS  
D7  
B
LSB MSB  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
0
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
MOSI  
MISO  
MSB  
LSB MSB  
LSB  
Figure 17-8. SPI Serial Port Access, Write Mode, CPOL = 1, CPHA = 1  
SCK  
CS  
D7  
B
LSB MSB  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
LSB  
0
0
0
0
0
0
0
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
MOSI  
MISO  
MSB  
LSB MSB  
108 of 123  
DS26503 T1/E1/J1 BITS Element  
18. OPERATING PARAMETERS  
ABSOLUTE MAXIMUM RATINGS  
Voltage Range on Any Pin Relative to Ground………………………………………………………-1.0V to +6.0V  
Operating Temperature Range for DS26503L…………………………………………………………0°C to +70°C  
Operating Temperature Range for DS26503LN……………………………………………………..-40°C to +85°C  
Storage Temperature Range………………………………………………………………………...-55°C to +125°C  
Soldering Temperature…………………………………………………...See IPC/JEDEC J-STD-20A Specification  
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 18-1. Thermal Characteristics  
PARAMETER  
MIN  
TYP  
MAX  
NOTES  
Ambient Temperature  
-40°C  
1
+85LC  
Junction Temperature  
125LC  
2
Theta-JA () in Still Air  
46.3LC/W  
JA  
Table 18-2. Theta-JA () vs. Airflow  
JA  
FORCED AIR  
THETA-JA ()  
JA  
(meters per second)  
0
1
(Note 3)  
(Note 3)  
(Note 3)  
2.5  
The package is mounted on a four-layer JEDEC standard test board.  
Note 1:  
Note 2:  
Note 3:  
Theta-JA () is the junction-to-ambient thermal resistance, when the package is mounted on a  
JA  
four-layer JEDEC standard test board.  
At the time of release of this data sheet, these values were not available. Please consult the factory.  
Table 18-3. Recommended DC Operating Conditions  
(TA = 0°C to +70°C for DS26503L; TA = -40°C to +85°C for DS26503LN.)  
PARAMETER  
Logic 1  
Logic 0  
Supply  
SYMBOL  
VIH  
MIN  
2.0  
-0.3  
TYP  
MAX  
5.5  
+0.8  
3.465  
UNITS  
NOTES  
V
V
V
VIL  
VDD  
3.135  
3.3  
4
Applies to RVDD, TVDD, and DVDD.  
Note 4:  
Table 18-4. Capacitance  
(TA = +25°C)  
PARAMETER  
Input Capacitance  
Output Capacitance  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
pF  
NOTES  
CIN  
COUT  
5
7
pF  
109 of 123  
DS26503 T1/E1/J1 BITS Element  
Table 18-5. DC Characteristics  
(VDD = 3.3V M5%, TA = 0°C to +70°C for DS26503L; VDD = 3.3V M5%, TA = -40°C to +85°C for  
DS26503LN.)  
PARAMETER  
Supply Current  
SYMBOL  
MIN  
TYP  
MAX  
150  
UNITS  
NOTES  
IDD  
IIL  
ILO  
IOH  
IOL  
85  
mA  
Input Leakage  
Output Leakage  
Output Current (2.4V)  
Output Current (0.4V)  
-1.0  
+1.0  
1.0  
5
6
A  
A  
mA  
mA  
-1.0  
+4.0  
0.0V < VIN < VDD  
Applied to INT when tri-stated.  
Note 5:  
Note 6:  
110 of 123  
DS26503 T1/E1/J1 BITS Element  
19. AC TIMING PARAMETERS AND DIAGRAMS  
Capacitive test loads are 40pF for bus signals and 20pF for all others.  
19.1 Multiplexed Bus  
Table 19-1. AC Characteristics, Multiplexed Parallel Port  
(VDD = 3.3V M5%, TA = 0°C to +70°C for DS26503L; VDD = 3.3V M5%, TA = -40°C to +85°C for  
DS26503LN.)  
PARAMETER  
Cycle Time  
Pulse Width, DS Low or RD High  
SYMBOL MIN  
TYP  
MAX  
UNITS  
NOTES  
tCYC  
200  
100  
ns  
ns  
PWEL  
Pulse Width, DS High or RD Low  
Input Rise/Fall Times  
R/W Hold Time  
PWEH  
tR, tF  
tRWH  
100  
ns  
ns  
ns  
20  
10  
50  
R/W Setup Time Before DS High  
tRWS  
ns  
CS Setup Time Before DS, WR, or  
RD Active  
tCS  
20  
ns  
CS Hold Time  
Read Data Hold Time  
Write Data Hold Time  
tCH  
tDHR  
tDHW  
0
10  
5
ns  
ns  
ns  
50  
Muxed Address Valid to AS or  
tASL  
tAHL  
15  
10  
ns  
ns  
ALE Fall  
Muxed Address Hold Time  
Delay Time DS, WR, or RD to AS  
tASD  
PWASH  
tASED  
20  
30  
10  
ns  
ns  
ns  
or ALE Rise  
Pulse Width AS or ALE High  
Delay Time, AS or ALE to DS,  
WR, or RD  
Output Data Delay Time from DS  
or RD  
tDDR  
tDSW  
80  
ns  
ns  
Data Setup Time  
50  
111 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-1. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 00)  
t
CYC  
ALE  
PW  
ASH  
t
ASD  
WR  
RD  
t
ASED  
t
ASD  
PW  
EH  
t
t
CH  
PW  
CS  
EL  
CS  
t
t
ASL  
t
DHR  
DDR  
AD0-AD7  
t
AHL  
Figure 19-2. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 00)  
t
CYC  
ALE  
PW  
ASH  
t
ASD  
RD  
WR  
t
t
ASED  
ASD  
PW  
EH  
t
t
CH  
PW  
EL  
CS  
CS  
t
t
ASL  
DHW  
AD0-AD7  
t
t
AHL  
DSW  
112 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-3. Motorola Bus Timing (BTS = 1 / BIS[1:0] = 00)  
PW  
ASH  
AS  
PW  
EH  
t
t
ASED  
ASD  
DS  
PW  
EL  
t
CYC  
t
t
RWS  
RWH  
R/W  
t
t
DDR  
t
ASL  
DHR  
AD0-AD7  
(read)  
t
t
AHL  
t
CH  
CS  
CS  
t
DSW  
t
ASL  
AD0-AD7  
(write)  
t
DHW  
t
AHL  
A8 & A9  
113 of 123  
DS26503 T1/E1/J1 BITS Element  
19.2 Nonmultiplexed Bus  
Table 19-2. AC Characteristics, Non-Mux Parallel Port  
(VDD = 3.3V M5%, TA = 0°C to +70°C for DS26503L; VDD = 3.3V M5%, TA = -40°C to +85°C for  
DS26503LN.)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
NOTES  
Setup Time for A0 to A7, Valid to  
t1  
0
ns  
CS Active  
Setup Time for CS Active to  
Either RD, WR, or DS Active  
t2  
0
ns  
Delay Time from Either RD or  
t3  
t4  
75  
20  
ns  
ns  
DS Active to Data Valid  
Hold Time from Either RD, WR,  
or DS Inactive to CS Inactive  
0
5
Hold Time from CS Inactive to  
t5  
t6  
t7  
t8  
t9  
ns  
ns  
ns  
ns  
ns  
Data Bus Tri-State  
Wait Time from Either WR or DS  
75  
Activate to Latch Data  
Data Setup Time to Either WR or  
DS Inactive  
10  
10  
10  
Data Hold Time from Either WR  
or DS Inactive  
Address Hold from Either WR or  
DS Inactive  
114 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-4. Intel Bus Read Timing (BTS = 0 / BIS[1:0] = 01)  
A0 to A7  
D0 to D7  
Address Valid  
Data Valid  
t5  
5ns min/20ns max  
WR  
CS  
RD  
t1  
0ns min  
0ns min  
t2  
t3  
0ns min  
t4  
75ns max  
Figure 19-5. Intel Bus Write Timing (BTS = 0 / BIS[1:0] = 01)  
A0 to A7  
D0 to D7  
RD  
Address Valid  
t7  
10ns  
min  
t8  
10ns  
min  
t1  
0ns min  
t2  
CS  
t6  
t4  
0ns min  
0ns min  
75ns min  
WR  
115 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-6. Motorola Bus Read Timing (BTS = 1 / BIS[1:0] = 01)  
A0 to A7  
D0 to D7  
R/W  
Address Valid  
Data Valid  
5ns min. / 20ns max.  
t5  
t1  
0ns min.  
t2  
CS  
t3  
t4  
0ns min.  
0ns min.  
75ns max.  
DS  
Figure 19-7. Motorola Bus Write Timing (BTS = 1 / BIS[1:0] = 01)  
A0 to A7  
D0 to D7  
R/W  
Address Valid  
10ns  
min.  
10ns  
min.  
t8  
t7  
t1  
0ns min.  
t2  
CS  
t6  
t4  
0ns min.  
0ns min.  
75ns min.  
DS  
116 of 123  
DS26503 T1/E1/J1 BITS Element  
19.3 Serial Bus  
Table 19-3. AC Characteristics, Serial Bus  
(VDD = 3.3V M5%, TA = 0°C to +70°C for DS26503L; VDD = 3.3V M5%, TA = -40°C to +85°C for  
DS26503LN.)  
CHARACTERISTIC (2)  
SYMBOL MIN MAX UNITS  
DIAGRAM  
Operating Frequency  
NUMBER (1)  
fBUS(S)  
10  
MHz  
Slave  
1
2
3
Cycle Time: Slave  
Enable Lead Time  
Enable Lag Time  
Clock (CLK) High Time  
Slave  
tCYC(S)  
tLEAD(S)  
tLAG(S)  
100  
15  
15  
ns  
ns  
ns  
4
5
6
7
tCLKH(S)  
tCLKL(S)  
tSU(S)  
50  
50  
5
40  
ns  
ns  
ns  
ns  
Clock (CLK) Low Time  
Slave  
Data Setup Time (inputs)  
Slave  
Data Hold Time (inputs)  
Slave  
tH(S)  
15  
0
CPHA = 0  
tA(CP0)  
8
Access Time, Slave (3)  
ns  
CPHA = 1  
tA(CP1)  
tDIS(S)  
tV(S)  
0
20  
25  
40  
9
Disable Time, Slave (4)  
ns  
ns  
Data Valid Time, After Enable Edge  
10  
Slave (5)  
Data Hold Time, Outputs, After Enable Edge  
Slave  
11  
tHD(S)  
5
ns  
Numbers refer to dimensions in the following Figure 19-8 and Figure 19-9.  
All timing is shown with respect to 20% VDD and 70% VDD, unless otherwise noted. 100pF load on all SPI pins.  
Time to data active from high-impedance state.  
Hold time to high-impedance state.  
With 100pF on all SPI pins.  
Note 1:  
Note 2:  
Note 3:  
Note 4:  
Note 5:  
117 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-8. SPI Interface Timing Diagram, CPHA = 0, BIS[1:0] = 10  
CS  
INPUT  
1
3
5
4
CLK INPUT  
CPOL = 0  
4
2
CLK INPUT  
CPOL = 1  
5
8
9
MISO  
SLAVE MSB  
BITS 6-1  
10  
SLAVE LSB  
11  
NOTE  
INPUT  
11  
6
7
MOSI  
MSB  
BITS 6-1  
LSB  
OUTPUT  
Note: Not defined, but usually MSB of character just received.  
Figure 19-9. SPI Interface Timing Diagram, CPHA = 1, BIS[1:0] = 10  
CS  
INPUT  
1
5
CLK INPUT  
CPOL = 0  
4
2
3
CLK INPUT  
CPOL = 1  
5
4
8
9
10  
MISO  
NOTE  
BITS 6-1  
BITS 6-1  
SLAVE LSB  
SLAVE MSB  
OUTPUT  
11  
6
7
10  
MOSI  
LSB  
MSB  
INPUT  
Note: Not defined, but usually LSB of character previously transmitted.  
118 of 123  
DS26503 T1/E1/J1 BITS Element  
19.4 Receive Side AC Characteristics  
Table 19-4. Receive Side AC Characteristics  
(VDD = 3.3V M5%, TA = 0°C to +70°C for DS26503L; VDD = 3.3V M5%, TA = -40°C to +85°C for  
DS26503LN.)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
488  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
1
2
5
3
3
4
4
RCLK Period  
tCP  
648  
158.4  
tCH  
tCL  
tCH  
tCL  
200  
200  
150  
150  
RCLK Pulse Width  
RCLK Pulse Width  
RCLK to RSER Delay  
RCLK to RS Delay  
tD1  
20  
50  
ns  
tD2  
ns  
E1 mode.  
T1 or J1 mode.  
Jitter attenuator enabled in the receive path.  
Jitter attenuator disabled or enabled in the transmit path.  
6312kHz mode.  
Note 1:  
Note 2:  
Note 3:  
Note 4:  
Note 5:  
119 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-10. Receive Timing, T1/E1  
RCLK  
t
D1  
RSER  
RS  
t
E1 = MSB of Channel 1  
T1 = F-Bit  
D2  
120 of 123  
DS26503 T1/E1/J1 BITS Element  
19.5 Transmit Side AC Characteristics  
Table 19-5. Transmit Side AC Characteristics  
(VDD = 3.3V M5%, TA = -40°C to +85°C.)  
PARAMETER  
TCLK Period  
SYMBOL  
MIN  
TYP  
488  
648  
MAX  
UNITS  
ns  
NOTES  
1
2
3
tCP  
ns  
ns  
158.4  
tCH  
tCL  
tR, tF  
75  
75  
ns  
ns  
ns  
TCLK Pulse Width  
TCLK Rise and Fall Times  
TCLK Setup to TSER, TS  
25  
tSU  
tD2  
ns  
ns  
4
5
Delay TCLK to TS  
50  
20  
Delay TCLKO to TPOSO and  
TNEGO  
tDD  
ns  
E1 mode.  
Note 1:  
Note 2:  
Note 3:  
Note 5:  
Note 6:  
T1 or J1 mode.  
6312kHz mode.  
TS in input mode.  
TS in output mode.  
121 of 123  
DS26503 T1/E1/J1 BITS Element  
Figure 19-11. Transmit Timing, T1/E1  
t
CP  
t
t
CL  
CH  
t
t
F
R
TCLK  
TSER  
t
SU  
t
HD  
t
D2  
TS1  
TS2  
t
SU  
TCLKO  
TPOSO, TNEGO  
t
DD  
NOTES:  
1) TS in output mode.  
2) TS in input mode.  
20. REVISION HISTORY  
REVISION  
DESCRIPTION  
New product release (with  
DS26502).  
070904  
122 of 123  
DS26503 T1/E1/J1 BITS Element  
21. PACKAGE 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.)  
123 of 123  
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  
© 2004 Maxim Integrated Products S Printed USA  
are registered trademarks of Maxim Integrated Products, Inc., and Dallas Semiconductor Corporation.  

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