LXT9782BC [ETC]
LAN TRANSCEIVER|OCTAL|BGA|272PIN|PLASTIC ; LAN收发器|八路| BGA | 272PIN |塑料\n
| 型号： | LXT9782BC |
| 厂家： | 
ETC |
| 描述： | LAN TRANSCEIVER|OCTAL|BGA|272PIN|PLASTIC
|
| 文件： | 总78页 (文件大小：1146K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LXT9762/9782
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Datasheet
General Description
The LXT9782 is an eight-port PHY Fast Ethernet Transceiver that supports IEEE 802.3 physical
layer applications at both 10 and 100 Mbps. The LXT9762 offers the same features and
functionality in a six-port device. This data sheet uses the singular designation “LXT97x2” to
refer to both devices.
The LXT97x2 interfaces multiple Serial Media Independent Interface (SMII) compliant
controllers to 10BASE-T and/or 100BASE-TX media.
All network ports provide a combination twisted-pair (TP) or pseudo-ECL (PECL) interface for
a 10/100BASE-TX or 100BASE-FX connection.
The LXT97x2 provides three discrete LED drivers for each port, and eight global serial LED
outputs. It supports both half- and full-duplex operation at 10 and 100 Mbps and requires only a
single 3.3V power supply.
Application
■ 100BASE-T, 10/100-TX, or 100BASE-FX Switches and multi-port NICs.
Product Features
■ Multiple independent IEEE 802.3-
compliant 10/100 ports with integrated
filters
■ JTAG boundary scan
■ Multiple Serial MII (SMII) ports for
independent PHY port operation
■ Proprietary Optimal Signal Processing
(OSP™) design improves SNR by 3 dB
over ideal analog filters
■ Configurable via MDIO port or external
control pins
■ Maskable interrupts
■ Robust baseline wander correction for
■ Very low power consumption
improved 100BASE-TX performance
(400 mW per port, typical)
■ 100BASE-FX fiber-optic capability on all
■ 3.3V operation
■ 208-pin PQFP and 272-lead BGA
■ 0-70oC ambient temperature range
ports
■ Supports both auto-negotiation and legacy
systems without auto-negotiation capability
As of January 15, 2001, this document replaces the Level One document
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII.
Order Number: 249039-001
January 2001
Information in this document is provided in connection with Intel® products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not
intended for use in medical, life saving, or life sustaining applications.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for
future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The LXT9762/9782 may contain design defects or errors known as errata which may cause the product to deviate from published specifications.
Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800-
548-4725 or by visiting Intel’s website at http://www.intel.com.
Copyright © Intel Corporation, 2001
*Third-party brands and names are the property of their respective owners.
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Contents
.
1.0
2.0
Preliminary Pin Assignments and Signal Descriptions...........................10
Functional Description...........................................................................................20
2.1
2.2
Introduction..........................................................................................................20
2.1.1 OSP™ Architecture................................................................................20
2.1.2 Comprehensive Functionality.................................................................20
Interface Descriptions..........................................................................................21
2.2.1 10/100 Network Interface .......................................................................21
2.2.2 SMII Data Interface ................................................................................22
2.2.3 Configuration Management Interface.....................................................22
Operating Requirements .....................................................................................25
2.3.1 Power Requirements..............................................................................25
2.3.2 Clock Requirements...............................................................................25
Initialization..........................................................................................................25
2.4.1 Hardware Configuration Settings ...........................................................26
2.4.2 Reset......................................................................................................27
2.4.3 Power-Down Mode.................................................................................28
Link Establishment ..............................................................................................28
2.5.1 Auto-Negotiation.....................................................................................28
2.5.2 Parallel Detection ...................................................................................29
Serial MII Operation ............................................................................................29
2.6.1 Reference Clock.....................................................................................31
2.6.2 SYNC Pulse ...........................................................................................31
2.6.3 Transmit Data Stream ............................................................................31
2.6.4 Receive Data Stream .............................................................................32
2.6.5 Loopback................................................................................................33
2.6.6 Collision..................................................................................................33
100 Mbps Operation............................................................................................34
2.7.1 100BASE-X Network Operations ...........................................................34
2.7.2 .100BASE-X Protocol Sublayer Operations ...........................................35
10 Mbps Operation..............................................................................................39
2.8.1 10T Preamble Handling..........................................................................40
2.8.2 10T Dribble Bits......................................................................................40
2.8.3 10T Link Test..........................................................................................40
2.8.4 10T Jabber .............................................................................................40
Monitoring Operations.........................................................................................40
2.9.1 Serial LED Functions..............................................................................40
2.9.2 Per-Port LED Driver Functions...............................................................42
2.9.3 Monitoring Auto-Negotiation...................................................................43
2.9.4 Using the Quick Status Register ............................................................44
Boundary Scan (JTAG1149.1) Functions............................................................44
2.10.1 Boundary Scan Interface........................................................................44
2.10.2 State Machine ........................................................................................45
2.10.3 Instruction Register ................................................................................45
2.10.4 Boundary Scan Register ........................................................................45
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
Datasheet
3
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
3.0
Application Information.........................................................................................46
3.1
Design Recommendations..................................................................................46
3.1.1 General Design Guidelines ....................................................................46
3.1.2 Power Supply Filtering ...........................................................................46
3.1.3 Power and Ground Plane Layout Considerations..................................47
3.1.4 MII Terminations ....................................................................................47
3.1.5 The RBIAS Pin.......................................................................................47
3.1.6 The Twisted-Pair Interface.....................................................................47
3.1.7 The Fiber Interface.................................................................................48
Typical Application Circuits .................................................................................49
3.2
4.0
5.0
6.0
Test Specifications..................................................................................................53
Register Definitions ................................................................................................63
Package Specifications.........................................................................................77
4
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figures
1
2
3
4
5
6
7
8
LXT 9782 Block Diagram ......................................................................................9
LXT9782HC (PQFP) Preliminary Pin Assignments............................................10
LXT9782BC (PBGA) Preliminary Pin Assignments............................................11
LXT9762HC (PQFP) Preliminary Pin Assignments ............................................12
LXT97x2 Interfaces ............................................................................................21
Port Address Scheme .........................................................................................23
Management Interface Read Frame Structure ...................................................23
Management Interface Write Frame Structure ...................................................24
Interrupt Logic ....................................................................................................24
Initialization Sequence .......................................................................................26
Hardware Control Settings .................................................................................27
Link Establishment Process ...............................................................................29
Simplified SMII Application Diagram ..................................................................30
100Mbps Serial MII Data Flow ...........................................................................31
Serial MII Transmit Synchronization ..................................................................32
Loopback Paths...................................................................................................33
Serial MII Receive Synchronization ....................................................................33
100BASE-X Frame Format ...............................................................................34
Protocol Sublayers .............................................................................................36
Serial LED Streams.............................................................................................42
LED Pulse Stretching ..........................................................................................43
Quick Status Register..........................................................................................44
Power and Ground Supply Connections ............................................................49
Typical Twisted-Pair Interface ............................................................................50
Typical Fiber Interface ........................................................................................51
Typical Serial LED Interface................................................................................52
MII Sync Timing...................................................................................................56
100BASE-TX Receive Timing .............................................................................56
SMII Output Delay Test Setup............................................................................57
100BASE-TX Transmit Timing ............................................................................57
100BASE-FX Receive Timing .............................................................................58
100BASE-FX Transmit Timing ............................................................................58
10BASE-T Receive Timing..................................................................................59
10BASE-T Transmit Timing.................................................................................59
Auto-Negotiation and Fast Link Pulse Timing ....................................................60
Fast Link Pulse Timing .......................................................................................60
MDIO Write Timing (MDIO Sourced by MAC) ....................................................61
MDIO Read Timing (MDIO Sourced by PHY) ....................................................61
Power-Up Timing ................................................................................................62
Reset and Power-Down Recovery Timing .........................................................62
PHY Identifier Bit Mapping ..................................................................................68
LXT97x2 PQFP Package Specification...............................................................77
LXT97x2 PBGA Package Specification...............................................................78
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Datasheet
5
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Tables
1
LXT97x2 Serial MII Signal Descriptions..............................................................13
2
3
4
5
6
7
8
9
LXT97x2 Signal Detect/TP Select Signal Descriptions.......................................14
LXT97x2 Network Interface Signal Descriptions.................................................14
LXT97x2 JTAG Test Signal Descriptions............................................................15
LXT97x2 Miscellaneous Signal Descriptions ......................................................15
LXT97x2 Power Supply Signal Descriptions.......................................................16
LXT97x2 LED Signal Descriptions......................................................................17
Unused Pins........................................................................................................19
Hardware Configuration Settings ........................................................................27
SMII Signal Summary .........................................................................................30
RX Status Encoding Bit Definitions.....................................................................33
4B/5B Coding......................................................................................................36
BSR Mode of Operation......................................................................................45
Supported JTAG Instructions..............................................................................45
Device ID Register ..............................................................................................45
Magnetics Requirements ....................................................................................48
Absolute Maximum Ratings ................................................................................53
Operating Conditions ..........................................................................................53
Digital I/O Characteristics 1.................................................................................54
Digital I/O Characteristics - SMII Pins.................................................................54
Required REFCLK and SYNC Characteristics....................................................54
100BASE-TX Transceiver Characteristics ..........................................................55
100BASE-FX Transceiver Characteristics ..........................................................55
10BASE-T Transceiver Characteristics...............................................................55
MII Sync Timing Parameters...............................................................................56
100BASE-TX Receive Timing Parameters .........................................................56
100BASE-TX Transmit Timing Parameters ........................................................57
100BASE-FX Receive Timing Parameters .........................................................58
100BASE-FX Transmit Timing Parameters ........................................................58
10BASE-T Receive Timing Parameters..............................................................59
10BASE-T Transmit Timing Parameters.............................................................59
Auto-Negotiation and Fast Link Pulse Timing Parameters .................................60
MDIO Timing Parameters ...................................................................................61
Power-Up Timing Parameters............................................................................62
Reset and Power-Down Recovery Timing Parameters.......................................62
Register Set ........................................................................................................63
Register Bit Map..................................................................................................64
Control Register (Address 0)...............................................................................66
Status Register (Address 1)................................................................................66
PHY Identification Register 1 (Address 2)...........................................................67
PHY Identification Register 2 (Address 3)...........................................................68
Auto-Negotiation Advertisement Register (Address 4) .......................................68
Auto-Negotiation Link Partner Base Page Ability Register (Address 5)..............69
Auto-Negotiation Expansion (Address 6)............................................................70
Auto-Negotiation Next Page Transmit Register (Address 7)...............................71
Auto-Negotiation Link Partner Next Page Receive Register (Address 8) ...........71
Port Configuration Register (Address 16, Hex 10)..............................................72
Quick Status Register (Address 17, Hex 11) ......................................................72
Interrupt Enable Register (Address 18, Hex 12) .................................................73
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
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34
35
36
37
38
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44
45
46
47
48
49
6
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
50
51
52
53
Interrupt Status Register (Address 19, Hex 13) ..................................................74
LED Configuration Register (Address 20, Hex 14)..............................................75
Transmit Control Register #1 (Address 28).........................................................76
Transmit Control Register #2 (Address 30).........................................................76
Datasheet
7
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Revision History
Revision
Date
Description
8
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 1. LXT 9782 Block Diagram
QCLK
Global Functions
QSTAT
ADD_<4:0>
Management /
Mode Select
Logic & LED
Drivers
RESET
MDC
MDIO
PWRDWN
REFCLK
SYNC
Clock
Generator
MDINT
Register Set
TxSLEW<1:0>
+
Manchester
Encoder
10
TP
Driver
OSP
™
Pulse
TXDn
TPFOPn
TPFONn
Parallel/Serial
Converter
Scrambler
& Encoder
-
100
TP / Fiber
Out
Shaper
+
ECL
Driver
Auto
Negotiation
Mgmt Counters
Register Set
-
8
3
LEDS_<7:0>
LEDLAT
SD/TPn
LED
Logic
OSP
™
+
Media
Select
LEDCLK
Clock
Generator
Adaptive EQ with
BaseLine Wander
Cancellation
100TX
100FX
10BT
Port LED
Configuration
-
+
ED/CFGn_<3:1>
RXDn
TPFIPn
TPFINn
Manchester
Decoder
TP / Fiber
In
Serial to
Parallel
Converter
10
OSP
™
Slicer
-
+
Decoder &
Descrambler
100
Carrier Sense
Data Valid
Error Detect
-
Per-Port Functions
PORT 0
PORT 1
PORT 2
PORT 3
PORT 4
PORT 5
PORT 6
PORT 7
Datasheet
9
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
1.0
Preliminary Pin Assignments and Signal
Descriptions
Figure 2. LXT9782HC (PQFP) Preliminary Pin Assignments
156..........TPFIN7
155..........VCCR
154..........TPFOP7
153..........TPFON7
152..........GNDA
151..........TPFON6
150..........TPFOP6
149..........VCCT
148..........VCCR
147..........TPFIN6
146..........TPFIP6
145..........GNDA
144..........GNDA
143..........TPFIP5
142..........TPFIN5
141..........VCCR
140..........TPFOP5
139..........TPFON5
138..........GNDA
137..........TPFON4
136..........TPFOP4
135..........VCCT
134..........VCCR
133..........TPFIN4
132..........TPFIP4
131..........GNDA
130..........GNDA
129..........TPFIP3
128..........TPFIN3
127..........VCCR
126..........VCCT
125..........TPFOP3
124..........TPFON3
123..........GNDA
122..........TPFON2
121..........TPFOP2
120..........VCCR
119..........TPFIN2
118..........TPFIP2
117..........GNDA
116..........GNDA
115..........TPFIP1
114..........TPFIN1
113..........VCCR
112..........VCCT
111..........TPFOP1
110..........TPFON1
109..........GNDA
108..........TPFON0
107..........TPFOP0
106..........VCCR
105..........TPFIN0
GNDD....... 1
N/C....... 2
TXD7....... 3
RXD7....... 4
N/C....... 5
N/C....... 6
N/C....... 7
TXD6....... 8
RXD6....... 9
N/C....... 10
N/C....... 11
N/C....... 12
N/C....... 13
N/C....... 14
VCCIO....... 15
GNDD....... 16
TXD5....... 17
RXD5....... 18
N/C....... 19
N/C....... 20
N/C....... 21
TXD4....... 22
RXD4....... 23
N/C....... 24
N/C....... 25
N/C....... 26
N/C....... 27
N/C....... 28
N/C....... 29
TXD3....... 30
VCCIO....... 31
GNDD....... 32
RXD3....... 33
N/C....... 34
N/C....... 35
N/C....... 36
TXD2....... 37
RXD2....... 38
N/C....... 39
N/C....... 40
N/C....... 41
Part #
LOT #
FPO #
LXT9782HC XX
XXXXXX
XXXXXXXX
Rev #
N/C....... 42
N/C....... 43
N/C....... 44
N/C....... 45
N/C....... 46
N/C....... 47
GNDD....... 48
GNDD....... 49
GNDD....... 50
GNDD....... 51
VCCIO....... 52
Package Topside Markings
Marking
Definition
LXT9782 is the unique identifier for this product family.
Part #
Identifies the particular silicon “stepping” (Refer to Specification Update for additional stepping
information.)
Rev #
Lot #
Identifies the batch.
FPO #
Identifies the Finish Process Order.
10
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 3. LXT9782BC (PBGA) Preliminary Pin Assignments
1
2
NC
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20
LED/
SD6/
TP6
TP
FIN7
TP
FIP7
LED/
CFG1_2
LED/
CFG3_1
LED/
LED/
LED/
CFG2_2
LED/
LEDS_4
LEDS_7
NC
NC
NC
NC
NC
QCLK GNDD
VCCD
LEDS_3
TRST
VCCT
VCCT
GNDA
GNDA
A
B
C
D
E
F
CFG7_3
CFG5_2 CFG6_1
CFG4_2
A
B
C
D
E
F
LED/
CFG0_1
LED
CLK
SD5/
TP5
TP
FON7
TP
FOP7
LED/
CFG5_3
LED/
CFG2_3
LED/
LED/
CFG3_3
NC
GNDD
TXD7
NC
QSTAT
GNDD
VCCD VCCD LEDS_1 LEDS_5
CFG6_2
TMS
LED/
CFG2_1
LED/
CFG4_1
SD4/
TP4
SD7/
TP7
TP
FON6
TP
FOP6
LED/
CFG0_3
LED/
CFG6_3
LED/
CFG1_3
LED/
CFG7_2
LED/
CFG7_1
RXD7
NC
GNDD
TDO
TCK
VCCIO
TXD6
GNDD
NC
LEDS_2
LEDS_6
TDI
TP
FIN6
LEDS
_0
LED
LATCH
TP
FIP6
LED/
CFG1_1
LED/
CFG5_1
LED/
CFG3_2 CFG4_3
LED/
LED/
CFG0_2
VCCR
GNDD
VCCIO
GNDA
VCCT
RXD6
NC
VCCR GNDA VCCT
TP
FIN5
TP
FIP5
NC
GNDA
GNDA
NC
VCCIO
NC
NC
TP
FON5
TP
FOP5
GNDA
GNDA
TXD5
GNDD GNDD
G
H
J
G
H
J
TP
FOP4
TP
FON4
RXD5
NC
NC
NC
NC
NC
NC
VCCR GNDA
VCCR GNDA
GNDA GNDA
TP
FIN4
TP
FIP4
GNDD GNDD GNDD GNDD
GNDD GNDD GNDD GNDD
GNDD GNDD GNDD GNDD
GNDD GNDD GNDD GNDD
NC
RXD4
NC
TXD4
NC
NC
VCCT
VCCT
VCCT
K
L
K
L
NC
TXD3
GNDA GNDA VCCT
TP
TP
FIP3
GNDA
GNDA
GNDA
GNDA
RXD3 GNDD GNDD
VCCR
VCCIO
NC
M
N
P
R
T
M
N
P
R
T
FIN3
TP
FON3
TP
FOP3
VCCR
NC
RXD2
NC
NC
NC
NC
NC
NC
TXD2
NC
TP
FOP2
TP
FON2
GNDA
GNDA
NC
NC
NC
TP
FIN2
TP
FIP2
NC
NC
VCCR GNDA VCCT
VCCT
GNDD
NC
SD1/
TP1
SD2/
TP2
SD3/
TP3
TP
FIN1
TP
FIP1
NC
NC
GNDD
RXD0
GNDD
NC
NC
NC
NC
NC
NC
GNDD
MDC
NC TxSLEW_1 GNDD MDINT
RESET
GNDA VCCR GNDA
SD0/
U
V
W
Y
U
V
W
Y
TP
FOP1
TP
FON1
ADD_3
ADD_0
REFCLK
ADD_2 ADD_1
TXD1
RXD1
NC
NC
TXD0
NC
NC
GNDS GNDD
RBIAS
VCCIO
NC
GNDA
NC
NC
NC
TP0
TP
FOP0
TP
FON0
PAUSE
ADD_4
MDIO
NC
GNDD
GNDD
SYNC
GNDA VCCT
PWRDWN
MDDIS
NC
TP
FIP0
TP
FIN0
NC
NC TxSLEW_0 VCCD VCCD VCCD
GNDD GNDD
VCCD VCCD
VCCT
VCCIO
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20
1. Ports 6 and 7 are available only on the LXT9782. These ports are not bonded out on the LXT9762.
Datasheet
11
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 4. LXT9762HC (PQFP) Preliminary Pin Assignments
GNDD.......1
N/C .......2
TXD5.......3
RXD5 .......4
N/C .......5
156.......... TPFIN5
155.......... VCCR
154.......... TPFOP5
153.......... TPFON5
152.......... GNDA
151.......... TPFON4
150.......... TPFOP4
149.......... VCCT
148.......... VCCR
147.......... TPFIN4
146.......... TPFIP4
145.......... GNDA
144.......... GNDA
143.......... TPFIP3
142.......... TPFIN3
141.......... VCCR
140.......... TPFOP3
139.......... TPFON3
138.......... GNDA
137.......... N/C
N/C .......6
N/C .......7
TXD4.......8
RXD4 .......9
N/C .......10
N/C .......11
N/C .......12
N/C .......13
N/C .......14
VCCIO .......15
GNDD.......16
TXD3.......17
RXD3 .......18
N/C .......19
N/C .......20
N/C .......21
N/C .......22
N/C .......23
N/C .......24
N/C .......25
N/C .......26
N/C .......27
N/C .......28
N/C .......29
N/C .......30
136.......... N/C
135.......... N/C
134.......... N/C
133.......... N/C
132.......... N/C
131.......... N/C
130.......... N/C
129.......... N/C
128.......... N/C
127.......... N/C
Part #
LOT #
FPO #
VCCIO .......31
GNDD.......32
N/C .......33
N/C .......34
N/C .......35
N/C .......36
TXD2.......37
RXD2 .......38
N/C .......39
N/C .......40
N/C .......41
N/C .......42
N/C .......43
N/C .......44
N/C .......45
N/C .......46
N/C .......47
GNDD.......48
GNDD.......49
GNDD.......50
GNDD.......51
VCCIO .......52
LXT9762HC
XXXXXX
XXXXXXXX
126.......... N/C
125.......... N/C
124.......... N/C
Rev
123.......... GNDA
122.......... TPFON2
121.......... TPFOP2
120.......... VCCR
119.......... TPFIN2
118.......... TPFIP2
117.......... GNDA
116.......... GNDA
115.......... TPFIP1
114.......... TPFIN1
113.......... VCCR
112.......... VCCT
111.......... TPFOP1
110.......... TPFON1
109.......... GNDA
108.......... TPFON0
107.......... TPFOP0
106.......... VCCR
105.......... TPFIN0
1. Ports 6 and 7 are available only on the LXT9782. These ports are not bonded out on the LXT9762.
Package Topside Markings
Marking
Definition
Part #
Rev #
LXT9762 is the unique identifier for this product family.
Identifies the particular silicon “stepping” (Refer to Specification Update for additional stepping
information.)
Lot #
Identifies the batch.
FPO #
Identifies the Finish Process Order.
12
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 1. LXT97x2 Serial MII Signal Descriptions
9762
Pin#
9782 Pin#
Symbol
Type1
Signal Description2, 3
PQFP
PQFP
PBGA
Serial MII Data Interface Pins
59
54
37
17
8
59
54
37
30
22
17
8
W4
V2
N4
L3
TXD0
TXD1
TXD2
TXD3
TXD4
TXD5
TXD6
TXD7
RXD0
RXD1
RXD2
RXD3
RXD4
RXD5
RXD6
RXD7
Transmit Data - Ports 0-7. These serial input streams provide data to be
transmitted to the network. LXT97x2 clocks the data in synchronously to
REFCLK.
I
J2
3
G2
D4
C2
V5
W2
P2
M2
K1
H2
E2
C3
–
–
3
60
55
38
18
9
60
55
38
33
23
18
9
Receive Data - Ports 0-7. These serial output streams provide data
received from the network. LXT97x2 drives the data out synchronously to
REFCLK.
O
4
–
–
4
SMII Synchronization. The MAC must generate a SYNC pulse every 10
REFCLK cycles to synchronize the SMII.
90
92
90
92
W14
Y15
SYNC
I
I
Reference Clock. The LXT97x2 requires a 125 MHz SMII reference clock
input at this pin. Refer to Functional Description for detailed clock
requirements.
REFCLK
MII Control Interface Pins 3
Management Data Input/Output. Bidirectional serial data channel for
communication between the PHY and MAC or switch ASIC.
71
84
70
71
84
70
W8
U12
V8
MDIO
MDINT
MDC
I/O
OD
I
Management Data Interrupt. When bit 18.1 = 1, an active Low output on
this pin indicates status change.
Management Data Clock. Clock for the MDIO serial data channel.
Maximum frequency is 8 MHz.
Management Disable. When MDDIS is High, the MDIO is disabled from
read and write operations.
When MDDIS is Low at power up or reset, the Hardware Control Interface
pins control only the initial or “default” values of their respective register
bits. After the power-up/reset cycle is complete, bit control reverts to the
MDIO serial channel.
85
85
Y12
MDDIS
I
1. Type Column Coding: I = Input, O = Output, OD = Open Drain.
2. Ports 6 and 7 are available only on the LXT9782. These pins are not bonded out on the LXT9762.
3. The LXT97x2 supports the 802.3 MDIO register set. Specific bits in the registers are referenced using an “X.Y” notation,
where X is the register number (0-32) and Y is the bit number (0-15).
Datasheet
13
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 2. LXT97x2 Signal Detect/TP Select Signal Descriptions
9762
9782 Pin#
Pin#
Symbol
Type1
Signal Description2
PQFP
PQFP
PBGA
101
100
99
101
100
99
V16
U13
U14
U15
C16
B17
A17
SD0/TP0
SD1/TP1
SD2/TP2
SD3/TP3
SD4/TP4
SD5/TP5
SD6/TP6
Signal Detect - Ports 0 - 7. Tying the SD/TPn pins High or to a
PECL input sets bit 16.0 = 1 and the respective port is forced to FX
mode. Do not enable Auto-Negotiation if FX mode is selected. In
the absence of an active link, the pin must be pulled High to enable
loopback in FX mode. Do not enable Auto-Negotiation if FX mode is
selected.
161
160
159
–
98
I
The SD/TPn pins have internal pull-downs. When not using FX
mode, SD/TPn pins should be tied to GNDA.
162
161
160
TP Select - Ports 0 - 7. Tying the SD/TPn pins Low sets bit 16.0 = 0
and forces the port to TP mode. The operating mode of each port
can be set to 10BASE-T or 100BASE-TX, half- or full-duplex, and
auto-negotiation or manual control via the hardware control interface
pins as shown in Table 9 on page 27.
–
159
C17
SD7/TP7
1. Type Column Coding: I = Input, O = Output.
2. Ports 6 and 7 are available only on the LXT9782. These pins are not bonded out on the LXT9762.
Table 3. LXT97x2 Network Interface Signal Descriptions
9762 Pin#
PQFP
9782 Pin#
Symbol
Type1
Signal Description 2
PQFP
PBGA
107, 108
111, 110
121, 122
140, 139
150, 151
154, 153
– , –
107, 108
111, 110
121, 122
125, 124
136, 137
140, 139
150, 151
154, 153
W19,W20
V20, V19
P19, P20
N20, N19
H19, H20
G20, G19
C19, C20
B20, B19
TPFOP0, TPFON0
TPFOP1, TPFON1
TPFOP2, TPFON2
TPFOP3, TPFON3
TPFOP4, TPFON4
TPFOP5, TPFON5
TPFOP6, TPFON6
TPFOP7, TPFON7
Twisted-Pair/Fiber Outputs, Positive & Negative -
Ports 0-7.
During 100BASE-TX or 10BASE-T operation, TPFO
pins drive 802.3 compliant pulses onto the line.
O
During 100BASE-FX operation, TPFO pins produce
differential PECL outputs for fiber transceivers.
– , –
104, 105 104, 105 Y19, Y20 TPFIP0, TPFIN0
115, 114 115, 114 U20, U19 TPFIP1, TPFIN1
118, 119 118, 119 R19, R20 TPFIP2, TPFIN2
I
Twisted-Pair/Fiber Inputs, Positive & Neg-
ative - Ports 0-7.
During 100BASE-TX or 10BASE-T opera-
tion, TPFI pins receive differential 100BASE-
TX or 10BASE-T signals from the line.
143, 142 129, 128
M20,
M19
TPFIP3, TPFIN3
During 100BASE-FX operation, TPFI pins
receive differential PECL inputs from fiber
transceivers.
146, 147 132, 133
J20, J19 TPFIP4, TPFIN4
157, 156 143, 142 F20, F19 TPFIP5, TPFIN5
– , –
– , –
146, 147 D19, D20 TPFIP6, TPFIN6
157, 156 A20, A19 TPFIP7, TPFIN7
1. Type Column Coding: I = Input, O = Output.
2. Ports 6 and 7 are available only on the LXT9782. These pins are not bonded out on the LXT9762.
14
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 4. LXT97x2 JTAG Test Signal Descriptions
97x21
Pin#
9782
Pin#
Symbol
Type2
Signal Description
PQFP
163
PBGA
D14
C15
B16
TDI
TDO
TMS
TCK
TRST
Test Data Input. Test data sampled with respect to the rising edge of TCK.
Test Data Output. Test data driven with respect to the falling edge of TCK.
Test Mode Select.
I / IP
O
164
165
I / IP
I / ID
I / IP
166
D15
A16
Test Clock. Clock input for JTAG test (REFCLK).
Test Reset. Reset input for JTAG test.
167
1. Pin numbers apply to both the LXT9762 and the LXT9782.
2. Type Column Coding: I = Input, O = Output, OD = Open Drain, IP = Weak Internal Pull-up, ID = Weak Internal Pull-down.
Table 5. LXT97x2 Miscellaneous Signal Descriptions
97x21 Pin#
Symbol
Type2
Signal Description3
PQFP
PBGA
Tx Output Slew Controls 0 and 1. These pins select the TX output slew rate
(rise and fall time) as follows:
TxSLEW_1
TxSLEW_0
Slew Rate (Rise and Fall Time)
TxSLEW_0
TxSLEW_1
76
77
Y8
0
0
1
1
0
1
0
1
2.5 ns
3.1 ns
3.7 ns
4.3 ns
I
U10
Pause. Setting this pin High causes LXT97x2 to advertise Pause capabilities on
all ports during auto-negotiation.
I
I
79
82
83
W10
W12
V12
PAUSE
PWRDWN
RESET
Power Down. When High, forces LXT97x2 into Power-Down mode. This pin is
OR’ed with the Power-Down bit (0.11). Refer to discussion on page 28 and to
Table 38 on page 66 for more information.
Reset. This active Low input is OR’ed with the control register Reset bit (0.15).
When held Low, outputs are forced to inactive state.
I
1. Pin numbers apply to both the LXT9762 and the LXT9782.
2. Type Column Coding: A = Analog, I = Input, O = Output, OD = Open Drain.
3. The LXT97x2 supports the 802.3 MDIO register set. Specific bits in the registers are referenced using an “X.Y” notation,
where X is the register number (0-32) and Y is the bit number (0-15).
Datasheet
15
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 5. LXT97x2 Miscellaneous Signal Descriptions (Continued)
97x21 Pin#
Symbol
Type2
Signal Description3
PQFP
PBGA
97
96
95
94
93
W16 ADD_4
V15 ADD_3
V13 ADD_2
V14 ADD_1
W15 ADD_0
I
I
I
I
I
Address <4:0>. Sets base address. Each port adds its port number
(starting with 0) to this address to determine its PHY address.
Port 0 Address = Base + 0.
Port 1 Address = Base + 1.
Port 2 Address = Base + 2.
Port 3 Address = Base + 3.
Port 4 Address = Base + 4.
Port 5 Address = Base + 5.
Port 6 Address = Base + 6 (LXT9782 Only).
Port 7 Address = Base + 7 (LXT9782 Only).
102
V17 RBIAS
AI
Bias. This pin provides bias current for the internal circuitry. Must be
tied to ground through a 22.1 kΩ 1% resistor.
206
207
B4
A3
QSTAT
QCLK
O
I
Quick Status. Provides for continuous PHY status updates, without the
need for constant polling.
Quick Clock. Clock used for sending out QSTAT information. Maxi-
mum frequency is 25 MHz.
1. Pin numbers apply to both the LXT9762 and the LXT9782.
2. Type Column Coding: A = Analog, I = Input, O = Output, OD = Open Drain.
3. The LXT97x2 supports the 802.3 MDIO register set. Specific bits in the registers are referenced using an “X.Y” notation,
where X is the register number (0-32) and Y is the bit number (0-15).
Table 6. LXT97x2 Power Supply Signal Descriptions
97x21 Pin#
Symbol
Type
Signal Description
PQFP
PBGA
A12, B11, B12, Y9, Y10,
Y11, Y16, Y17
Digital Power Supply - Core. +3.3V supply for
core digital circuits.
VCCD
80, 87, 88, 89, 179
–
–
–
Digital Power Supply - I/O Ring. +3.3V supply
for digital I/O circuits. Regardless of the IO supply,
digital I/O pins remain tolerant of 5V signal levels.
VCCIO
15, 31, 52, 67, 193, 208
C4, D5, G1, M1, Y6, V1
106, 113, 120, 127, 134,
141, 148, 155
D17, E17, H17, J17,
M17, N17, T17, U17
Analog Power Supply. +3.3V supply for all
analog receive circuits.
VCCR
VCCT
A18, B18, E19, E20, K19,
K20, L19, L20, T19, T20,
W18, Y18
LXT9762 and LXT9782:
112, 149
Analog Power Supply. +3.3V supply for all
analog transmit circuits.
–
LXT9782 Only:
126, 135
A4, B2, B8, C12, D11,
E4, G3, G4, J9 - J12, K9
- K12, L9 - L12, M3, M4,
M9 - M12, T4, U5, U8,
U11, V11, W5, W11,
W13, Y13, Y14
–
1, 16, 32, 48-51, 53, 68,
72-75, 81, 86, 91, 178,
192
Digital Ground. Ground return for both core and
I/O digital supplies (VCCD and VCCIO).
GNDD
1. Unless otherwise noted, pin numbers apply to both the LXT9762 and the LXT9782.
16
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 6. LXT97x2 Power Supply Signal Descriptions (Continued)
97x21 Pin#
Symbol
Type
Signal Description
PQFP
PBGA
C18, D16, D18, E18,
F17, F18, G17, G18,
H18, J18, K17, K18, L17,
L18, M18, N18, P17,
P18, R17, R18, T18,
U16, U18, V18, W17
–
LXT9762 and LXT9782:
103, 109, 116, 117, 123,
138, 144, 145, 152, 158
Analog Ground. Ground return for analog
supply. All ground pins can be tied together using
a single ground plane.
GNDA
GNDS
LXT9782 Only:
130, 131
78
V10
Substrate Ground. Ground for chip substrate.
–
1. Unless otherwise noted, pin numbers apply to both the LXT9762 and the LXT9782.
Table 7. LXT97x2 LED Signal Descriptions
9762
9782 Pin#
Pin#
Symbol
Type1
Signal Description2
PQFP
PQFP
PBGA
177
176
175
174
173
172
171
170
168
169
177
176
175
174
173
172
171
170
168
169
D12
B13
C13
A14
A13
B14
C14
A15
B15
D13
LEDS_0
LEDS_1
LEDS_2
LEDS_3
LEDS_4
LEDS_5
LEDS_6
LEDS_7
LEDCLK
LEDLATCH
Serial LEDs 0 - 7. Each serial LED output indicates a particular status
condition for every port. Bit 0 is assigned to Port 0, bit 1 is assigned to
Port 1, etc. There are 8 possible LEDs per port, for a total of 48
display LEDs. However, typical equipment designs use no more than
3 LEDs per port, selected by the designer. Using per-event, rather
than per-port outputs reduces the number of serial shift registers
required. Instead of requiring an external serial-to-parallel shift
register for each port, this method requires only one per LED type,
reducing board space and component costs. Refer to “Serial LED
Functions” on page 40 for details.
O
O
O
LED Clock. 1 MHz clock for LED serial data output.
LED Latch. Framing signal for serial LED outputs.
Port 0 LED Drivers 1 -3. These pins drive LED indicators for Port 0.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
203
204
205
203
204
205
B5
D6
C5
LED/CFG0_1
LED/CFG0_2
LED/CFG0_3
I
OD
OS
Port 0 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
Port 1 LED Drivers 1 -3. These pins drive LED indicators for Port 1.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
200
201
202
200
201
202
D7
A5
C6
LED/CFG1_1
LED/CFG1_2
LED/CFG1_3
I
OD
OS
Port 1 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
1. Type Column Coding: I = Input, O = Output, OD = Open Drain, OS = Open Source.
2. Ports 6 and 7 are available only on the LXT9782. These pins are not bonded out on the LXT9762.
Datasheet
17
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 7. LXT97x2 LED Signal Descriptions (Continued)
9762
9782 Pin#
Pin#
Symbol
Type1
Signal Description2
PQFP
PQFP
PBGA
Port 2 LED Drivers 1 -3. These pins drive LED indicators for Port 2.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
197
198
199
197
198
199
C7
A6
B6
LED/CFG2_1
LED/CFG2_2
LED/CFG2_3
I
OD
OS
Port 2 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
Port 3 LED Drivers 1 -3. These pins drive LED indicators for Port 3.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
186
187
188
194
195
196
A7
D8
B7
LED/CFG3_1
LED/CFG3_2
LED/CFG3_3
I
OD
OS
Port 3 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
Port 4 LED Drivers 1 -3. These pins drive LED indicators for Port 4.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
183
184
185
189
190
191
C8
A8
D9
LED/CFG4_1
LED/CFG4_2
LED/CFG4_3
I
OD
OS
Port 4 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
Port 5 LED Drivers 1 -3. These pins drive LED indicators for Port 5.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
180
181
182
186
187
188
D10
A9
LED/CFG5_1
LED/CFG5_2
LED/CFG5_3
I
OD
OS
Port 5 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
B9
Port 6 LED Drivers 1 -3. These pins drive LED indicators for Port 6.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
–
–
–
183
184
185
A10
B10
C9
LED/CFG6_1
LED/CFG6_2
LED/CFG6_3
I
OD
OS
Port 6 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
Port 7 LED Drivers 1 -3. These pins drive LED indicators for Port 7.
Each output indicates one of several available status conditions as
selected by the LED Configuration Register (refer to Table 51 on
page 75 for details).
–
–
–
180
181
182
C11
C10
A11
LED/CFG7_1
LED/CFG7_2
LED/CFG7_3
I
OD
OS
Port 7 Configuration Inputs 1-3. When operating in Hardware
Control Mode, these pins also provide configuration control options
(refer to Table 9 on page 27 for details).
1. Type Column Coding: I = Input, O = Output, OD = Open Drain, OS = Open Source.
2. Ports 6 and 7 are available only on the LXT9782. These pins are not bonded out on the LXT9762.
18
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 8. Unused Pins
97x2 Pin#
PQFP
9782 Pin#
PBGA
Symbol
Type
Signal Description
LXT9762 and
LXT9782:
A1,A2, B1, B3, C1, D1 - D3, E1, E3, F1
- F4, H1, H3, H4, J1, J3, J4, K2 - K4,
L1, L2, L4, N1 - N3, P1, P3, P4, R1 -
R4, T1 - T3, U1 - U4, U6, U7, U9, V3,
V4, V6, V7, V9, W1, W3, W6, W7, W9,
Y1 - Y5, Y7
No Connection - LXT97x2. These pins are
not used on either the LXT9762 or LXT9782
and should not be connected.
2, 5-7, 10-14,
19-21, 24-29,
34-36, 39-47,
56-58, 61-66, 69
N/C
–
LXT9762 Only:
No Connection - LXT9762 Only. These
additional pins are not used on the
LXT9762 and should not be connected.
98, 124 - 137,
162, 189 - 191,
194 - 196
N/C
–
Datasheet
19
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
2.0
Functional Description
2.1
Introduction
The LXT9782 eight-port Fast Ethernet 10/100 Transceiver supports 10 Mbps and 100 Mbps
networks. It complies with all applicable requirements of IEEE 802.3. Each port directly drives
either a 100BASE-TX line (up to 100 meters) or a 10BASE-T line (up to 185 meters). The
LXT9782 also supports 100BASE-FX operation via a Pseudo-ECL (PECL) interface. The
LXT9762 offers the same features and functionality in a six-port device. This data sheet uses the
singular designation “LXT97x2” to refer to both devices.
2.1.1
OSP™ Architecture
Intel's LXT97x2 incorporates high-efficiency Optimal Signal Processing™ design techniques,
combining the best properties of digital and analog signal processing to produce a truly optimal
device.
The receiver utilizes decision feedback equalization to increase noise and cross-talk immunity by
as much as 3 dB over an ideal all-analog equalizer. Using OSP mixed-signal processing techniques
in the receive equalizer avoids the quantization noise and calculation truncation errors found in
traditional DSP-based receivers (typically complex DSP engines with A/D converters). This
improves receiver noise and cross-talk performance.
The OSP signal processing scheme requires substantially less computational logic than traditional
DSP-based designs. This lowers power consumption and also reduces the logic switching noise
generated by DSP engines clocked at speeds up to 125 MHz. Logic switching noise can be a
considerable source of EMI generated on the device’s power supplies.
The OSP-based LXT97x2 provides improved data recovery, EMI performance, and power
consumption.
2.1.2
Comprehensive Functionality
The LXT97x2 performs all functions of the Physical Coding Sublayer (PCS) and Physical Media
Attachment (PMA) sublayer as defined in the IEEE 802.3 100BASE-X specification. This device
also performs all functions of the Physical Media Dependent (PMD) sublayer for 100BASE-TX
connections.
On power-up, the LXT97x2 reads its configuration pins to check for forced operation settings. If
not configured for forced operation, each port uses auto-negotiation/parallel detection to
automatically determine line operating conditions. The LXT97x2 provides half-duplex and full-
duplex operation at 100 Mbps and 10 Mbps.
If the PHY device on the other side of the link supports auto-negotiation, the LXT97x2 will auto-
negotiate with it using Fast Link Pulse (FLP) Bursts. If the PHY partner does not support auto-
negotiation, the LXT97x2 will automatically detect the presence of either link pulses (10 Mbps
PHY) or Idle symbols (100 Mbps PHY) and set its operating conditions accordingly.
20
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
The LXT97x2 provides an individual serial MII (SMII) for each network port. The SMII ports
provide for communication between the Media Access Controllers (MACs) and the network ports.
The SMII bit stuffing protocol is automatically set once the network port operating conditions have
been determined
Figure 5. LXT97x2 Interfaces
LXT97x2
TXDn
RXDn
TPFOPn
SMII
DATA
I/F
TPFONn
Network
I/F
SYNC
TPFIPn
TPFINn
REFCLK
MDIO
MDC
MDIO
Mgmt
I/F
MDINT
MDDIS
H/W Config
Mgmt I/F &
Port LEDs
VCC
LED/CFGn_n
LEDS_n
Serial LED
I/F
LEDLATCH
LEDCLK
RBIAS
VCCIO
22.1k
+3.3V
ADD<4:0>
Quick
Status
I/F
QSTAT
QCLK
VCCD
GNDD
+3.3V
.01uF
2.2
Interface Descriptions
2.2.1
10/100 Network Interface
The LXT97x2 supports both 10BASE-T and 100BASE-TX Ethernet over twisted-pair, or 100
Mbps Ethernet over fiber media (100BASE-FX). Each network interface port consists of four
external pins (two differential signal pairs). The pins are shared between twisted-pair (TP) and
fiber. Refer to Table 2 on page 14 for specific pin assignments.
The LXT97x2 output drivers generate either 100BASE-TX, 10BASE-T, or 100BASE-FX PECL
output. When not transmitting data, the LXT97x2 generates 802.3-compliant link pulses or idle
code. Input signals are decoded either as a 100BASE-TX, 100-BASE-FX, or 10BASE-T input,
depending on the mode selected. The interface speed is determined by auto-negotiation/parallel
detection or manual control.
2.2.1.1
Twisted-Pair Interface
When operating at 100 Mbps, the LXT97x2 continuously transmits and receives MLT3 symbols.
When not transmitting data, the LXT97x2 generates “IDLE” symbols.
During 10 Mbps operation, Manchester-encoded data is exchanged. When no data is being
exchanged, the line is left in an idle state.
Datasheet
21
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
The LXT97x2 supports either 100BASE-TX or 10BASE-T connections over 100Ω, Category 5,
Unshielded Twisted Pair (UTP) cable. Only a transformer, RJ-45 connector, load resistor, and
bypass capacitors are required to complete this interface. On the receive side, the internal
impedance is high enough that it has no practical effect on the external termination circuit. On the
transmit side, Intel’s patented waveshaping technology shapes the outgoing signal to help reduce
the need for external EMI filters. Four slew rate settings (refer to Table 5 on page 15) allow the
designer to match the output waveform to the magnetic characteristics.
2.2.1.2
2.2.2
Fiber Interface
The LXT97x2 provides a PECL interface suitable for driving a fiber-optic coupler. The PECL
interface complies with the ANSI X3.166 specification.
Fiber ports cannot be enabled via auto-negotiation; they must be enabled via the Hardware Control
Interface or MDIO registers.
SMII Data Interface
The LXT97x2 provides six or eight independent SMII ports with a common reference clock and
SYNC signal, as well as an MDIO management interface. The SMII Data Interface exchanges data
between the LXT97x2 and up to eight Media Access Controllers (MACs).
2.2.3
Configuration Management Interface
The LXT97x2 provides both a Hardware Control Interface (via the LED/CFG pins) and an MDIO
interface for device configuration and management.
2.2.3.1
Hardware Control Interface
The LXT97x2 provides a Hardware Control Interface for applications where the MDIO is not
desired. The Hardware Control Interface uses the three LED driver pins for each port. Refer to the
discussion in the Initialization section for additional details.
2.2.3.2
MDIO Management Interface
The LXT97x2 supports the IEEE 802.3 MII Management Interface also known as the Management
Data Input/Output (MDIO) Interface. This interface allows upper-layer devices to monitor and
control the LXT97x2. The MDIO interface consists of a physical connection, a specific protocol
that runs across the connection, and an internal set of addressable registers. Some registers are
required and their functions are defined by the IEEE 802.3 specification. Additional registers
allow for expanded functionality.
Specific bits in the registers are referenced using an “X.Y” notation, where X is the register number
(0-32) and Y is the bit number (0-15).
The physical interface consists of a data line (MDIO) and clock line (MDC). Operation of this
interface is controlled by the MDDIS input pin. When MDDIS is High, the MDIO read and write
operations are disabled and the Hardware Control Interface provides primary configuration control.
When MDDIS is Low, the MDIO port is enabled for both read and write operations and the
Hardware Control Interface is not used. The timing for the MDIO Interface is shown in Table 33 on
page 61. MDIO read and write cycles are shown in Figure 7 (read) and Figure 8 (write).
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
MII Addressing
The protocol allows one controller to communicate with multiple LXT97x2 chips. Pins
ADD_<4:0> determine the base address. Each port adds its port number (0 through n) to the base
address to obtain its port address as shown in Figure 6.
Figure 6. Port Address Scheme
BASE ADDR
(ex. ADDR=4)
LXT9782
PHY ADDR (BASE+0)
ex. 4
Port 0
Port 1
Port 2
Port 3
Port 4
Port 5
Port 6
Port 7
PHY ADDR (BASE+1)
ex. 5
PHY ADDR (BASE+2)
ex. 6
PHY ADDR (BASE+3)
ex. 7
PHY ADDR (BASE+4)
ex. 8
PHY ADDR (BASE+5)
ex. 9
PHY ADDR (BASE+6)
ex. 10
PHY ADDR (BASE+7)
ex. 11
1. Ports 6 and 7 not available on the LXT9762.
Figure 7. Management Interface Read Frame Structure
MDC
MDIO
(Read)
High Z
D0
A4
A3
A0
R4
R3
R0
D14 D1
D15
Z
0
32 "1"s
0
1
1
0
Turn
Around
Data
Read
Idle
Preamble
ST
Op Code
PHY Address
Register Address
Write
Datasheet
23
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 8. Management Interface Write Frame Structure
MDC
MDIO
Write)
A4
A3
A0
R4
R3
R0
D15
D14
D1
D0
32 "1"s
0
1
0
1
0
1
Turn
Around
Idle
Preamble
ST
Op Code
PHY Address
Register Address
Data
Idle
Write
MII Interrupts
The LXT97x2 provides a single interrupt pin available to all ports. Interrupt logic is shown in
Figure 9. The LXT97x2 also provides two dedicated interrupt registers for each port. Register 18
(Table 49 on page 73) provides interrupt enable and mask functions and Register 19 (Table 50 on
page 74) provides interrupt status. Setting bit 18.1 = 1, enables a port to request interrupt via the
MDINT pin. An active Low on this pin indicates a status change on the LXT97x2. However,
because it is a shared interrupt, it does not indicate which port is requesting service.
Interrupts may be caused by five conditions:
• Receive Monitor counter full
• Auto-negotiation complete
• Speed status change
• Duplex status change
• Link status change
Figure 9. Interrupt Logic
Event X Enable Reg
Event X Status Reg
AND
OR
Port
Combine
Logic
Interrupt Pin
.
.
AND
.
.
.
Per Event
.
Per port
Force Interrupt
Interrupt Enable
1. Interrupt (Event) Status Register is cleared on read.
2. X = Any Interrupt capability
24
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
2.3
Operating Requirements
2.3.1
Power Requirements
The LXT97x2 requires four power supply inputs, VCCD, VCCR, VCCT and VCCIO. The digital
and analog circuits require 3.3 V supplies (VCCD, VCCR and VCCT). These inputs may be
supplied from a single source although decoupling is required to each respective ground.
An additional supply may be used for the SMII (VCCIO). VCCIO should be supplied from the
same power source used to supply the controller on the other side of the SMII interface. Refer to
Table 20 on page 54 for the SMII I/O characteristics.
As a matter of good practice, these supplies should be as clean as possible. Typical filtering and
decoupling are shown in Figure 23 on page 49.
2.3.2
Clock Requirements
Reference Clock
2.3.2.1
The LXT97x2 requires a constant 125 MHz reference clock (REFCLK). The reference clock is
used to generate transmit signals and recover receive signals. A crystal-based clock is
recommended over a derived clock (i.e, PLL-based) to minmize transmit jitter. Refer to Table 21
on page 54 for clock timing requirements.
2.3.2.2
SYNC Signal
The LXT97x2 requires a 12.5 MHz input pulse for SMII synchronization. See“SYNC Pulse” on
page 31
2.3.2.3
2.3.2.4
Serial LED Clock
The LXT97x2 requires a 1 MHz clock input to synchronize the serial LED output.
Quick Status Clock
The LXT97x2 requires a clock input (up to 25 MHz) to synchronize the Quick Status output.
2.4
Initialization
When the LXT97x2 is first powered on, reset, or encounters a link failure state, it checks the MDIO
register configuration bits to determine the line speed and operating conditions to use for the
network link. The configuration bits may be set by the Hardware Control Interface pins or by an
MDIO write operation as shown in Figure 10.
The following modes are available using either Hardware Control or MDIO Control:
• Force network link to 100FX (Fiber).
• Force network link operation to:
— 100TX, Full-Duplex
Datasheet
25
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
— 100TX, Half-Duplex
— 10BASE-T, Full-Duplex
— 10BASE-T, Half-Duplex
• Allow auto-negotiation / parallel-detection.
When the network link is forced to a specific configuration, the LXT97x2 immediately begins
operating the network interface as commanded. When auto-negotiation is enabled, the LXT97x2
begins the auto-negotiation / parallel-detection operation.
Figure 10. Initialization Sequence
Power-up or Reset
Read H/W Control
Interface
Initialize MDIO Registers
MDIO Control
Mode
Hardware Control
Mode
MDDIS Voltage
Level?
Low
High
Pass Control to MDIO
Interface (Read/Write)
Disable MDIO Read and
Write Operations
Software
Reset?
Yes
Reset MDIO Registers to
values read at H/W
Control Interface at last
Hardware Reset
2.4.1
Hardware Configuration Settings
The LXT97x2 provides a hardware option to set the initial device configuration. The LED/CFG
drivers can operate as either open drain or open source circuits as shown in Figure 11. This
provides three control bits per port, as listed in Table 9. In applications where all ports configured
the same, several pins may be tied together with a single resistor.
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 11. Hardware Control Settings
VCC
Configuration Bit = 1
Configuration Bit = 0
LED/CFG Pin
LED/CFG Pin
1. LEDs will automatically correct their
polarity upon power-up or reset.
.
Table 9. Hardware Configuration Settings
Desired Configuration
Pin Settings
Resulting Register Bit Values
Control Register AN Advertisement Register
LED/CFGn_1
AutoNeg
Mode
Speed
Mode
Duplex
Mode
AutoNeg
0.12
Speed
0.13
FD
0.8
100FD
4.8
100TX
4.7
10 FD
4.6
10T
4.5
1
2
3
Half
Full
Half
Full
Half
Full
Half
Full
0
0
0
0
1
1
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
10
100
0
1
X X X X 2
Disabled
0
Auto-Negotiation
Advertisement
0
1
0
1
100
0
0
1
Enabled3
1
1
1
0
10/100
1
1. These pins set the default values for registers 0 and 4 accordingly.
2. X = Don’t Care.
3. Do not select Fiber mode with Auto-Negotiation enabled.
2.4.2
Reset
The LXT97x2 provides both hardware and software resets. Configuration control of Auto-
Negotiation, speed and duplex mode selection is handled differently for each. During a hardware
reset, settings for bits 0.13, 0.12 and 0.8 are read in from the pins (refer to Table 38 on page 66).
During a software reset (0.15 = 1), these bit settings are not re-read from the pins. They revert back
to the values that were read in during the last hardware reset. Therefore, any changes to pin values
made since the last hardware reset will not be detected during a software reset.
During a hardware reset, register information is unavailable for 1 ms after de-assertion of the reset.
During a software reset (0.15 = 1) the registers are available for reading. The reset bit should be
polled to see when the part has completed reset (0.15 = 0).
Datasheet
27
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
2.4.3
Power-Down Mode
The LXT97x2 offers both global and per-port power-down modes.
2.4.3.1
Global (Hardware) Power Down
The global power-down mode is controlled by PWRDWN pin 82 (PQFP) or pin W12 (PBGA).
When PWRDWN is High, the following conditions are true:
• All LXT97x2 ports and clock are shut down.
• All outputs are tri-stated.
• All weak pad pull-up and pull-down resistors are disabled.
• The MDIO registers are not accessible.
• The MDIO registers are reset after power down.
2.4.3.2
Port Power Down
Individual port power-down control is provided by bit 0.11 in the respective port Control Registers
(refer to Table 38 on page 66). During individual port power-down, the following conditions are
true:
• The individual port is shut down.
• The MDIO registers remain accessible.
• The MDIO registers are unaffected.
2.5
Link Establishment
2.5.1
Auto-Negotiation
The LXT97x2 attempts to auto-negotiate with its counter-part across the link by sending Fast Link
Pulse (FLP) bursts. Each burst consists of 33 link pulses spaced 62.5 µs apart. Odd link pulses
(clock pulses) are always present. Even link pulses (data pulses) may be present or absent to
indicate a “1” or a “0”. Each FLP burst exchanges 16 bits of data, which are referred to as a
“page”. All devices that support auto-negotiation must implement the “Base Page” defined by
IEEE 802.3 (Registers 4 and 5). LXT97x2 also supports the optional ‘Next Page’ function
(Registers 7 and 8).
2.5.1.1
Base Page Exchange
By exchanging Base Pages, the LXT97x2 and its link partner communicate their capabilities to
each other. Both sides must receive at least three identical base pages for negotiation to proceed.
Each side finds the highest common capabilities that both sides support. Both sides then exchange
more pages, and finally agree on the operating state of the line.
2.5.1.2
Next Page Exchange
Additional information, above that required by base page exchange is also sent via “Next Pages’.
The LXT97x2 fully supports the 802.3 method of negotiation via Next Page exchange.
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
2.5.1.3
Controlling Auto-Negotiation
When auto-negotiation is controlled by software, the following steps are recommended:
• After power-up, power-down, or reset, the power-down recovery time, as specified in Table 34
on page 62, must be exhausted before proceeding.
• Set the auto-negotiation advertisement register bits.
• Enable auto-negotiation (set MDIO bit 0.12 = 1).
Do not enable Auto-Negotiation if fiber mode is selected.
Figure 12. Link Establishment Process
Power-Up, Reset,
Link Failure
Start
Disable
Auto-Negotiation
Enable
0.12 = 0
0.12 = 1
Auto-Neg/Parallel Detection
Check Value
0.12
Go To Forced
Settings
Attempt Auto-
Negotiation
Listen for 100TX
Idle Symbols
Listen for 10T
Link Pulses
YES
NO
Done
Link Set
2.5.2
Parallel Detection
In parallel with auto-negotiation, the LXT97x2 also monitors for 10 Mbps Normal Link Pulses
(NLP) or 100 Mbps Idle symbols. If either is detected, the device automatically reverts to the
corresponding operating mode. Parallel detection allows the LXT97x2 to communicate with
devices that do not support auto-negotiation.
2.6
Serial MII Operation
The LXT97x2 exchanges transmit and receive data with the controller via the Serial MII (SMII).
The SMII performs the following functions:
• Conveys complete MII information between a 10/100 PHY and MAC with two pins per port.
Datasheet
29
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
• Allows a multi-port MAC/PHY communication with one system clock.
• Operates in both half and full duplex.
• Supports per-packet switching between 10 Mbps and 100 Mbps data rates.
The Serial MII operates at 125 MHz using a global reference clock and frame synchronization
signal (REFCLK and SYNC). Each port has an individual two-line data interface (TXDn and
RXDn). All signals are synchronous to REFCLK. Figure 13 is a simple SMII block diagram and
Table 10 summarizes the SMII signals.
Data is exchanged in 10-bit serial words. Each word contains one data byte (two nibbles of 4B
coded data) and two status bits. When the port is operating at 100 Mbps, each word contains a new
data byte. When the port is operating at 10 Mbps, each data byte is repeated 10 times.
Table 10. SMII Signal Summary
Signal
To
From
Purpose
TXD
RXD
PHY
MAC
PHY
MAC
PHY
MAC
Receive data & control
Transmit data & control
Synchronization
SYNC
MAC &
PHY
REFCLK
System Synchronization
1. Refer to Table 1 on page 13 for detailed signal descriptions.
Figure 13. Simplified SMII Application Diagram
8
8
TX
RX
LXT9782
SYNC
16 Port MAC
CLOCK
Clock
8
8
TX
RX
LXT9782
SYNC
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
.
Figure 14. 100Mbps Serial MII Data Flow
Strip
TX_EN &
TX_ER
Status
Bits
Serial Data Stream
To/From
2 Nibbles Tx/Rx Data
D0 D1 D2 D3
2 Symbols Tx/Rx Data
S0 S1 S2 S3 S4
MAC
S0 S1 D0 D1 D2
4B/5B
To/From
PMD
Insert
CRS &
RX_DV
Status
Bits
D3 D4 D5 D6 D7
D0 D1 D2 D3
S0 S1 S2 S3 S4
Sublayer
2.6.1
2.6.2
2.6.3
Reference Clock
REFCLK operates at 125 MHz. The transmit and receive data and control streams must always be
synchronized to REFCLK by the MAC and PHY. The LXT97x2 samples these signals on the
rising edge of REFCLK.
SYNC Pulse
The SYNC pulse delimits segment boundaries and synchronizes with REFCLK. The MAC must
continuously generate a SYNC pulse once every 10 REFCLK cycles. The SYNC pulse signals the
start of each new segment as shown in Figure 15 and Figure 17.
Transmit Data Stream
Transmit data and control information are signalled in ten bit segments. In 100 Mbps mode each
segment contains a new byte of data. In 10 Mbps mode the MAC must repeat a 10M serial word
on TXD ten times. LXT97x2 may sample that serial word at any point.
The SYNC pulse signals the start of a new segment as shown in Figure 15.
2.6.3.1
2.6.3.2
Transmit Enable
The MAC must assert the TX_EN bit in each segment of TXData, and de-assert TX_ENn after the
last segment of the packet.
Transmit Error
In 100BASE-x mode when the MAC asserts the TX_ER bit, the LXT97x2 will drive “H” symbols
onto the network interface. TX_ER does not have any function in 10M operation.
Datasheet
31
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 15. Serial MII Transmit Synchronization
CLOCK
SYNC
TX
TX_ER TX_EN TXD0 TXD1 TXD2 TXD3 TXD4 TXD5 TXD6 TXD7 TX_ER
2.6.4
Receive Data Stream
Receive data and control information are signalled in ten bit segments. In 100 Mbps mode each
segment contains a new byte of data. In 10 Mbps mode each segment is repeated ten times (except
for the CRS bit) and the MAC can sample any one of the ten segments.
2.6.4.1
2.6.4.2
Carrier Sense
The CRS bit (slot 0) is generated when a packet is received from the network interface. The CRS
bit is set in real time, even in 10 Mbps mode. (All other bits are repeated in 10 sequential
segments).
Receive Data Valid
The LXT97x2 asserts the RX_DV bit (slot 1) when it receives a valid packet. The assertion timing
changes depend on line operating speed:
• For 100TX and 100FX links, the RX_DV bit is asserted from the first nibble of preamble to
the last nibble of the data packet.
• For 10BT links, the entire preamble is truncated. The RX_DV bit is asserted with the first
nibble of the Start-of-Frame Delimiter (SFD) “5D” and remains asserted until the end of the
packet.
2.6.4.3
2.6.4.4
Receive Error
In 100BASE-X mode when the LXT97x2 receives an errored symbol from the network, it drives
“1110” on the associated RXD pin.
Receive Status Encoding
The LXT97x2 encodes status information onto the RXD line during IPG as listed in Table 11 on
page 33. Status bit RXD<5> indicates the validity of the upper nibble (RXD<7:4> of the last byte
of the previous frame). RXD and RX_DV are passed through the internal elasticity FIFO to
smooth any clock rate differences between the recovered clock and the 125 MHz reference clock.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
2.6.5
Loopback
A test loopback function is available for 100 Mbps SMII testing. Bit 0.14 must be set High for
correct operation. When data is looped back, whatever the MAC transmits is looped back in its
entirety, including the preamble. In FX mode, the respective SD/TPn pin must be pulled High to
enable loopback.
Figure 16. Loopback Paths
LXT97x2
FX Driver
TX Driver
Digital
Block
100X
Loopback
Analog
Block
SMII
2.6.6
Collision
The SMII interface does not provide a collision output and relies on the MAC to interpret COL
conditions using CRS and TX_EN. CRS is unaffected by the transmit path.
Figure 17. Serial MII Receive Synchronization
CLOCK
SYNC
RX
RXD0
RXER
RXD1
Speed
RXD2
Duplex
RXD3
Link
RXD4
Jabber
RXD5
Valid
RXD6
RXD6
RXD7
RXD7
CRS
CRS
RX_DV
Table 11. RX Status Encoding Bit Definitions
Signal
Definition
CRS
Carrier Sense - identical to MII, except that it is not an asynchronous signal.
Receive Data Valid - identical to MII. When RX_DV = 0, status information is
transmitted to the MAC. When RX_DV = 1, received data is transmitted to the
MAC.
0 = Status Byte
1 = Valid Data Byte
RX_DV
RX_ER
(RXD0)
Inter-frame status bit RXD0 indicates whether or not the PHY detected an error
somewhere in the previous frame.
0 = No Error
1 = Error
SPEED
(RXD1)
0 = 10Mbps
1 = 100Mbps
Inter-frame status bit RXD1 indicates port operating speed.
Inter-frame status bit RXD2 indicates port duplex condition.
DUPLEX
(RXD2)
0 = Half
1 = Full
1. Both RXD0 and RXD5 bits are valid in the segment immediately following a frame, and remain valid until the first data
segment of the next frame begins.
Datasheet
33
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 11. RX Status Encoding Bit Definitions (Continued)
Signal
Definition
Inter-frame status bit RXD3 indicates port link status.
Inter-frame status bit RXD4 indicates port jabber status.
LINK
(RXD3)
0 = Down
1 = Up
JABBER
(RXD4)
0 = OK
1 = Error
VALID
Inter-frame status bit RXD5 conveys the validity of the upper nibble of the last byte 0 = Invalid
(RXD5)
of the previous frame.
1 = Valid
RXD)
RXD7
Reserved
Ignore
This bit is set to 1.
Always = 1
1. Both RXD0 and RXD5 bits are valid in the segment immediately following a frame, and remain valid until the first data
segment of the next frame begins.
2.7
100 Mbps Operation
2.7.1
100BASE-X Network Operations
During 100BASE-X operation, the LXT97x2 transmits and receives 5-bit symbols across the
network link. Figure 18 shows the structure of a standard frame packet. When the MAC is not
actively transmitting data, the LXT97x2 sends out Idle symbols on the line.
In 100TX mode, the LXT97x2 scrambles the data and transmits it to the network using MLT-3 line
code. The MLT-3 signals received from the network are descrambled and decoded and sent across
the MII to the MAC.
In 100FX mode, the LXT97x2 transmits and receives NRZI signals across the PECL interface. An
external 100FX transceiver module is required to complete the fiber connection.
As shown in Figure 18, the MAC starts each transmission with a preamble pattern. As soon as the
LXT97x2 detects the start of preamble, it transmits a J/K Start-of-Stream Delimiter (SSD) symbol
to the network. It then encodes and transmits the rest of the packet, including the balance of the
preamble, the Start-of-Frame Delimiter (SFD), packet data, and CRC. Once the packet ends, the
LXT97x2 transmits the T/R End-of-Stream Delimiter (ESD) symbol and then returns to
transmitting Idle symbols.
Figure 18. 100BASE-X Frame Format
64-Bit Preamble
(8 Octets)
Destination and Source
Address (6 Octets each)
Packet Length
(2 Octets)
Data Field
(Pad to minimum packet size)
Frame Check Field InterFrame Gap / Idle Code
(4 Octets)
(> 12 Octets)
CRC
IFG
SFD
P0 P1 P6
DA DA SA SA L1
L2 D0 D1 Dn
I0
Replaced by
/T/R/ code-groups
End-of-Stream Delimiter (ESD)
Replaced by
Start-of-Frame
Delimiter (SFD)
/J/K/ code-groups
Start-of-Stream
Delimiter (SSD)
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
2.7.2
.100BASE-X Protocol Sublayer Operations
With respect to the 7-layer communications model, the LXT97x2 is a Physical Layer 1 (PHY)
device. The LXT97x2 implements the Physical Coding Sublayer (PCS), Physical Medium
Attachment (PMA), and Physical Medium Dependent (PMD) sublayers of the reference model
defined by the IEEE 802.3u specification. The following paragraphs discuss LXT97x2 operation
from the reference model point of view.
2.7.2.1
PCS Sublayer
The Physical Coding Sublayer (PCS) provides the MII interface, as well as the 4B/5B encoding/
decoding function described in Table 12 on page 36.
For 100TX and 100FX operation, the PCS layer provides IDLE symbols to the PMD-layer line
driver as long as TX_EN is de-asserted.
For 10T operation, the PCS layer merely provides a bus interface and serialization/de-serialization
function. 10T operation does not use the 4B/5B encoder.
Preamble Handling
When the MAC asserts TX_EN, the PCS substitutes a /J/K symbol pair, also known as the Start-of-
Stream Delimiter (SSD), for the first two nibbles received across the MII. The PCS layer continues
to encode the remaining MII data according to the 4B/5B coding rules until TX_EN is de-asserted.
It then returns to supplying IDLE symbols to the line driver.
In the receive direction, the PCS layer performs the opposite function, substituting two preamble
nibbles for the SSD.
Dribble Bits
The LXT97x2 handles dribbles bits in all modes. If between 1-4 dribble bits are received, the
nibble is passed across the SMII, padded with 1s if necessary. If between 5-7 dribble bits are
received, the second nibble is not sent onto the SMII bus.
Datasheet
35
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 19. Protocol Sublayers
MII Interface
LXT97x2
PCS
Sublayer
Encoder/Decoder
Serializer/De-serializer
PMA
Link/Carrier Detect
Sublayer
PECL Interface
PMD
Sublayer
Scrambler/
De-scrambler
Fiber Transceiver
100BASE-TX
100BASE-FX
Table 12. 4B/5B Coding
4B Code
3 2 1 0
5B Code
4 3 2 1 0
Code Type
Name
Interpretation
0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
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
0
1
2
3
4
5
6
7
8
9
A
B
C
1 1 1 1 0
0 1 0 0 1
1 0 1 0 0
1 0 1 0 1
0 1 0 1 0
0 1 0 1 1
0 1 1 1 0
0 1 1 1 1
1 0 0 1 0
1 0 0 1 1
1 0 1 1 0
1 0 1 1 1
1 1 0 1 0
Data 0
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
Data 7
Data 8
Data 9
Data A
Data B
Data C
DATA
1 1 0 1
1 1 1 0
D
E
1 1 0 1 1
1 1 1 0 0
Data D
Data E
1. The /I/ (Idle) code group is sent continuously between frames.
2. The /J/ and /K/ (SSD) code groups are always sent in pairs; /K/ follows /J/.
3. The /T/ and /R/ (ESD) code groups are always sent in pairs; /R/ follows /T/.
4. An /H/ (Error) code group is used to signal an error condition.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 12. 4B/5B Coding (Continued)
4B Code
3 2 1 0
5B Code
4 3 2 1 0
Code Type
Name
Interpretation
1 1 1 1
F
1 1 1 0 1
Data F
IDLE
undefined
I 1
1 1 1 11
Idle. Used as inter-stream fill code
Start-of-Stream Delimiter (SSD), part
1 of 2
0 1 0 1
0 1 0 1
J 2
K 2
T 3
R 3
H 4
1 1 0 0 0
1 0 0 0 1
0 1 1 0 1
0 0 1 1 1
0 0 1 0 0
Start-of-Stream Delimiter (SSD), part
2 of 2
CONTROL
End-of-Stream Delimiter (ESD), part
1 of 2
undefined
undefined
undefined
End-of-Stream Delimiter (ESD), part
2 of 2
Transmit Error. Used to force
signaling errors
undefined
undefined
undefined
undefined
undefined
undefined
undefined
undefined
undefined
undefined
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
0 0 0 0 0
0 0 0 0 1
0 0 0 1 0
0 0 0 1 1
0 0 1 0 1
0 0 1 1 0
0 1 0 0 0
0 1 1 0 0
1 0 0 0 0
1 1 0 0 1
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
Invalid
INVALID
Invalid
1. The /I/ (Idle) code group is sent continuously between frames.
2. The /J/ and /K/ (SSD) code groups are always sent in pairs; /K/ follows /J/.
3. The /T/ and /R/ (ESD) code groups are always sent in pairs; /R/ follows /T/.
4. An /H/ (Error) code group is used to signal an error condition.
2.7.2.2
PMA Sublayer
Link
In 100 Mbps mode, the LXT97x2 establishes a link whenever the scrambler becomes locked and
remains locked for approximately 50 ms. If the scrambler loses lock (<12 consecutive idle
symbols during a 2 ms window), the link is taken down. This provides a very robust link,
essentially filtering out any small noise hits that may otherwise disrupt the link. Furthermore,
100M idle patterns do not bring up a 10M link.
The LXT97x2 reports link failure via the MII status bits (1.2, 17.10, and 19.4) and interrupt
functions. If auto-negotiate is enabled, link failure causes the LXT97x2 to re-negotiate.
Datasheet
37
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Link Failure Override
The LXT97x2 normally transmits 100 Mbps data packets or Idle symbols only when the link is up,
and transmits only FLP bursts when the link is not up. Setting bit 16.14 = 1 overrides this function,
allowing the LXT97x2 to transmit data packets even when the link is down. This feature is
provided as a diagnostic tool. Note that auto-negotiation must be disabled to transmit data packets
in the absence of link. If auto-negotiation is enabled, the LXT97x2 automatically begins
transmitting FLP bursts if the link goes down.
Carrier Sense
For 100TX and 100FX links, a Start-of-Stream Delimiter (SSD) or /J/K symbol pair causes
assertion of carrier sense (CRS). An End-of-Stream Delimiter (ESD), or /T/R symbol pair causes
de-assertion of CRS. The PMA layer also de-asserts CRS if IDLE symbols are received without /
T/R; however, in this case the RX_ER bit in the RX Status Frame is asserted for one clock cycle
when CRS is de-asserted.
• For 10T links, CRS assertion is based on reception of valid preamble, and de-assertion on
reception of an End-of-Frame (EOF) marker.
Receive Data Valid
The LXT97x2 asserts the RX_DV bit when it receives a valid packet. However, RXD outputs zeros
until the received data is decoded and available for transfer to the controller.
2.7.2.3
Twisted-Pair PMD Sublayer
The twisted-pair Physical Medium Dependent (PMD) layer provides signal scrambling and
descrambling, line coding and decoding (MLT-3 for 100TX, Manchester for 10T), as well as
receiving, polarity correction, and baseline wander correction functions.
Scrambler/Descrambler (100TX Only)
The scrambler spreads the signal power spectrum and reduces EMI using an 11-bit, non-data-
dependent polynomial. The receiver automatically decodes the polynomial whenever IDLE
symbols are received.
The scrambler/descrambler can be bypassed by setting bit 16.12 = 1. The scrambler is
automatically bypassed when the fiber interface is enabled. Scrambler bypass provides diagnostic
and test support.
Baseline Wander Correction
The LXT97x2 provides a baseline wander correction function, making the device robust under all
network operating conditions. The MLT3 coding scheme used in 100BASE-TX is by definition
“unbalanced”. This means that the DC average value of the signal voltage can “wander”
significantly over short time intervals (tenths of seconds). This wander can cause receiver errors,
particularly in less robust designs, at long line lengths (100 meters). The exact characteristics of the
wander are completely data dependent.
The LXT97x2 baseline wander correction characteristics allow the LXT97x2 to recover error-free
data while receiving worst-case “killer” packets over all cable lengths.
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Polarity Correction
The LXT97x2 automatically detects and corrects for receive signal (TPIP/N) inversion. Reversed
polarity is detected if eight inverted link pulses, or four inverted EOF markers, are received
consecutively. If link pulses or data are not received by the maximum receive time-out period, the
polarity converter resets to a non-inverted state.
Fiber PMD Sublayer
The LXT97x2 provides a PECL interface for connection to an external fiber-optic transceiver.
(The external transceiver provides the PMD function for fiber media.) The LXT97x2 uses an
NRZI format for the fiber interface. The fiber interface operates at 100 Mbps and does not support
10FL applications.
Far End Fault Indications
The LXT97x2 Signal Detect pins receive signal fault indications from local fiber transceivers via
the SD pins. The device can also detect far end fault code in the received data stream. The
LXT97x2 “ORs” both fault conditions to set bit 1.4. Bit 1.4 is set once and clears when read.
Either fault condition causes the LXT97x2 to drop the link unless Forced Link Pass is selected
(16.14 = 1). Link down condition is then reported via interrupts and status bits.
In response to locally detected signal faults (SD activated by the local fiber transceiver), the
affected port can transmit the far end fault code if fault code transmission is enabled by bit 16.2.
• When bit 16.2 = 1, transmission of the far end fault code is enabled. The LXT97x2 transmits
far end fault code if fault conditions are detected by the Signal Detect pins.
• When bit 16.2 = 0, the LXT97x2 does not transmit far end fault code. It continues to transmit
idle code and may or may not drop link depending on the setting for bit 16.14.
2.8
10 Mbps Operation
The LXT97x2 operates as a standard 10BASE-T transceiver. Data transmitted by the MAC is
Manchester-encoded, and transmitted on the TPOP/N outputs. Received data is decoded and
passed to the MAC. The LXT97x2 supports all the standard 10 Mbps functions.
During 10BASE-T (10T) operation, the LXT97x2 transmits and receives Manchester-encoded data
across the network link. When the MAC is not actively transmitting data, the LXT97x2 sends out
link pulses on the line.
In 10T mode, the polynomial scrambler/descrambler is inactive. Manchester-encoded signals
received from the network are decoded by the LXT97x2 and sent across the MII to the MAC.
The LXT97x2 does not support fiber connections at 10 Mbps.
Datasheet
39
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
2.8.1
10T Preamble Handling
The LXT97x2 offers two options for preamble handling, selected by bit 16.5. In 10T Mode when
16.5 = 0, the LXT97x2 strips the entire preamble off of received packets. CRS is asserted
coincident with SFD. RX_DV is held Low for the duration of the preamble. When RX_DV is
asserted, the very first two nibbles driven by the LXT97x2 are the SFD “5D” hex followed by the
body of the packet.
In 10T mode with 16.5 = 1, the LXT97x2 passes the preamble through the MII and asserts RX_DV
and CRS simultaneously. In 10T loopback, the LXT97x2 loops back whatever the MAC transmits
to it, including the preamble.
2.8.2
2.8.3
10T Dribble Bits
The LXT97x2 device handles dribbles bits in all modes. If between 1-4 dribble bits are received,
the nibble is passed across the SMII, padded with 1s if necessary. If between 5-7 dribble bits are
received, the second nibble is not sent onto the SMII bus.
10T Link Test
In 10T mode, the LXT97x2 always transmit link pulses. If the Link Test function is enabled, it
monitors the connection for link pulses. Once link pulses are detected, data transmission is
enabled and remains enabled as long as either the link pulses or data transmission continue. If the
link pulses stop, data transmission is disabled.
If the Link Test function is disabled, the LXT97x2 transmits to the connection regardless of
detected link pulses. Link Test can be disabled by setting bit 16.14 = 1.
2.8.3.1
2.8.4
Link Failure
Link failure occurs if Link Test is enabled and no link pulses or packets are received. If this
condition occurs, the LXT97x2 returns to the link establishment mode selected at initialization.
10T Jabber
If a transmission exceeds the jabber timer, the LXT97x2 disables the transmit and loopback
functions. The LXT97x2 automatically exits jabber mode after the unjab time has expired. The
jabber timer can be disabled by setting bit 16.10 = 1.
2.9
Monitoring Operations
2.9.1
Serial LED Functions
The LXT97x2 provide eight serial LED outputs (LEDS7:0) which may be attached to external
HC595-type shift registers (refer to Figure 26 on page 52). The LEDCLK signal is used to shift
data into the 595’s internal shift register. The LEDLATCH signal is used to latch data from the
595’s internal shift register to the 595’s internal storage register. The LXT97x2 drives the LEDSn
and LEDLATCH outputs on the falling edge of LEDCLK. All serial LEDs will be stretched in
accordance with bits 20.1 and 20.3:2.
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Each serial output reports a specific status condition for all ports. Ports 0 through 7 are assigned
bits 0:7 in each stream (bits 3 and 4 are not used on the LXT9762).
The serial outputs report the following conditions for each port:
• LEDS0 Serial Output indicates Activity
0 = Active1 = Inactive
• LEDS1 Serial Output indicates Polarity (10 Mbps)
0 = Switched Polarity1 = Normal Polarity
• LEDS2 Serial Output indicates Duplex (D)
0 = Full Duplex1 = Half Duplex
• LEDS3 Serial Output indicates Link
0 = Link active1 = Link inactive
• LEDS4 Serial Output indicates Collision
0 = Collision active1 = Collision inactive
• LEDS5 Serial Output indicates Receive
0 = Receive active1 = Receive inactive
• LEDS6 Serial Output indicates Transmit
0 = Transmit active1 = Transmit inactive
• LEDS7 Serial Output indicates Speed
0 = 100 Mbps1 = 10 Mbps
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 20. Serial LED Streams
LEDCLK
(1 MHz)
activity activity activity activity activity activity
activity activity activity activity activity activity activity activity
(port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
LEDS(0)
LEDS(1)
LEDS(2)
LEDS(3)
LEDS(4)
LEDS(5)
LEDS(6)
LEDS(7)
LEDLATCH
(port 0) (port 1) (port 3) (port 5) (port 6) (port 7)
(port 2)
(port 4)
polarity polarity polarity polarity polarity polarity polarity polarity polarity polarity polarity polarity polarity polarity
(port 6) (port 7)
(port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
(port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
duplex
(port 0)
duplex
duplex
duplex
duplex
duplex
duplex
duplex duplex
duplex
duplex
(port 2)
duplex
duplex
duplex
(port 1) (port 2) (port 3) (port 4) (port 5) (port 6)
(port 0) (port 1)
(port 3) (port 4) (port 5)
(port 7)
link
(port 0)
link
link
link
(port 3)
link
link
link
link
link
link
link
link
link
link
(port 1) (port 2)
(port 4) (port 5) (port 6) (port 7) (port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
collision collision collision collision collision collision collision collision collision collision collision collision collision collision
(port 1) (port 2) (port 3) (port 4) (port 5) (port 6) (port 7) (port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
(port 0)
receive receive receive receive receive receive receive receive receive receive receive receive receive receive
(port 7) (port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
(port 0) (port 1) (port 2) (port 3) (port 4) (port 5) (port 6)
transmit transmit transmit transmit transmit transmit transmit transmit transmit transmit transmit transmit transmit transmit
(port 5)
(port 1) (port 2) (port 3) (port 4) (port 5) (port 6) (port 7) (port 0) (port 1) (port 2) (port 3) (port 4)
(port 0)
speed
speed
speed
speed
speed
speed
(port 5)
speed
(port 6)
speed speed
speed
speed
speed
speed
speed
(port 0) (port 1) (port 2) (port 3) (port 4)
(port 0) (port 1) (port 2) (port 3) (port 4) (port 5)
(port 7)
Spare on LXT9762
Spare on LXT9762
Alternate Port Positions for LXT9762
Port 5
LEDS(0:7)
Port 0
Port 1
Port 2
Spare
Spare
Port 3
Port 4
Port 5
Port 0
Port 1
Port 2
Spare
Spare
Port 3
2.9.2
Per-Port LED Driver Functions
The LXT97x2 incorporates three direct drive LEDs per port. On power up, all the LEDs outputs
are asserted for approximately 1 second after Reset is de-asserted. Each LED driver can be
programmed to indicate one of several status conditions using the LED Configuration Register.
Each per-port LED can be programmed (refer to Table 51 on page 75) to indicate one the following
conditions:
• Operating Speed
• Transmit Activity
• Receive Activity
• Collision Condition
• Link Status
• Duplex Mode
The LEDs can also be programmed to display various combined status conditions. For example,
setting bits 20.15:12 = 1101 produces the following combination of Link and Activity indications:
• If Link is down LED is off.
• If Link is up LED is on.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
• If Link is up AND activity is detected, the LED blinks at the stretch interval selected by bits
20.3:2 and continues to blink as long as activity is present.
The LED driver pins also provide manual configuration control during Hardware Control
operation. Refer to the discussion of “Hardware Control Interface” on page 22 for details.
2.9.2.1
LED Pulse Stretching
The LED Configuration Register also provides optional LED pulse stretching to 30, 60, or 100 ms.
If during this pulse stretch period, the event occurs again, the pulse stretch time will be further
extended.
When an event such as receiving a packet occurs it will be edge detected and it will start the stretch
timer. The LED driver will remain asserted until the stretch timer expires. If another event occurs
before the stretch timer expires then the stretch timer will be reset and the stretch time will be
extended.
When a long event (such as duplex status) occurs it will be edge detected and it will start the stretch
timer. When the stretch timer expires the edge detector will be reset so that a long event will cause
another pulse to be generated from the edge detector which will reset the stretch timer and cause
the LED driver to remain asserted. Figure 21 shows how the stretch operation functions.
Figure 21. LED Pulse Stretching
Event
LED
stretch
stretch
stretch
Note: The direct drive LED outputs in this diagram are shown as active Low.
2.9.3
Monitoring Auto-Negotiation
Auto-negotiation can be monitored as follows:
• Bit 17.7 is set to 1 once the auto-negotiation process is completed.
• Bits 1.2 and 17.10 are set to 1 once the link is established.
• Additional bits in Register 1 (refer to Table 39 on page 66) and Register 17 (refer to Table 48
on page 72) can be used to determine the link operating conditions and status.
2.9.3.1
Monitoring Next Page Exchange
The LXT97x2 offers an Alternate Next Page mode to simplify the next page exchange process.
Normally, bit 6.1 (Page Received) remains set until read. When Alternate Next Page mode is
enabled (16.1 = 1), bit 6.1 is automatically cleared whenever a new negotiation process takes place.
This prevents the user from reading an old value in 6.1 and assuming that Registers 5 and 8
(Partner Ability) contain valid information. Additionally, the LXT97x2 uses bit 6.5 to indicate
Datasheet
43
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
when the current received page is the base page. This information is useful for recognizing when
next pages must be resent due to a new negotiation process starting. Bits 6.1 and 6.5 are cleared
when read.
2.9.4
Using the Quick Status Register
The LXT97x2 continuously sends out the Quick Status Register contents on the QSTAT pin.
This output provides a continuous, real-time status update of several different LXT97x2 attributes
and modes including RX, TX, COL and the auto-negotiation process.
The 16 bits of the Quick Status Register are separated by a 16-bit signature frame
(1111111111111111) to simplify interface designs.
The LXT97x2 sources this status information separated by the signature with respect to the falling
edge of the QCLK input. An ASIC need supply only 1 clock output (up to 25 MHz) for multiple
PHY devices. Refer to Table 48 on page 72 for Quick Status bits descriptions.
Figure 22. Quick Status Register
16 BIT SIGNATURE
QSTAT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
QUICK STATUS REGISTER-Port 0
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
(0)
(0)
D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Port 2 thru n-1
QUICK STATUS REGISTER-Port n
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
(0)
(0)
1. QCLK is used to output the above information.
2. Bits D15 and D0 are always set to 0.
2.10
Boundary Scan (JTAG1149.1) Functions
LXT97x2 includes a IEEE 1149.1 boundary scan test port for board level testing. All digital input,
output, and input/output pins are accessible via boundary scan.
2.10.1
Boundary Scan Interface
This interface consists of five pins (TMS,TDI,TDO, TCK and TRST). It includes a state machine,
data register array, and instruction register. The TMS and TDI pins are internally pulled up. TCK is
internally pulled down. TDO does not have an internal pull-up or pull-down.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
2.10.2
2.10.3
2.10.4
State Machine
The TAP controller is a 16 state machine driven by the TCK and TMS pins. Upon reset, the
TEST_LOGIC_RESET state is entered. The state machine is also reset when TMS is High for five
TCK periods.
Instruction Register
The IDCODE instruction is always invoked after the state machine resets. The decode logic
ensures the correct data flow to the data registers according to the current instruction. Valid
instructions are listed in Table 14.
Boundary Scan Register
Each BSR cell has two stages. A flip-flop and a latch are used for the serial shift stage and the
parallel output stage. There are four modes of operation as listed in Table 13.
Table 13. BSR Mode of Operation
Mode
Description
1
2
3
4
Capture
Shift
Update
System Function
Table 14. Supported JTAG Instructions
Name
EXTEST
Code
Description
External Test
Data Register
0000000000000000
1111111111111110
1111111111111110
1111111111001111
1111111111101111
1111111111111111
BSR
IDCODE
SAMPLE
High Z
ID Code Inspection
Sample Boundary
Force Float
ID REG
BSR
Bypass
BSR
Clamp
Clamp
BYPASS
Bypass Scan
Bypass
Table 15. Device ID Register
31:28
27:12
11:8
7:1
0
Version
Part ID (hex)
Jedec Continuation Characters
JEDEC ID1
Reserved
2622 (LXT9762)
2636 (LXT9782)
0000
0000
111 1110
1
1. The JEDEC ID is an 8-bit identifier. The MSB is for parity and is ignored.
Intel’s JEDEC ID is FE (1111 1110) which becomes 111 1110.
Datasheet
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
3.0
Application Information
3.1
Design Recommendations
The LXT97x2 complies with IEEE requirements and provides outstanding receive Bit Error Rate
(BER) and long-line-length performance. Obtaining maximum performance from the LXT97x2
requires attention to detail and good design practices. Refer to the LXT97x2 Design and Layout
Guide for detailed design and layout information.
3.1.1
General Design Guidelines
Adhering to generally accepted design practices minimizes noise levels on power and ground
planes. Up to 50 mV of noise is considered acceptable. 50 to 80 mV of noise is considered
marginal. High-frequency switching noise can be reduced, and its effects can be eliminated, by
following these simple guidelines throughout the design:
• Fill in unused areas of the signal planes with solid copper and attach them with vias to a VCC
or ground plane that is not located adjacent to the signal layer.
• Use ample bulk and decoupling capacitors throughout the design (a value of .01 µF is
recommended for decoupling caps).
• Provide ample power and ground planes.
• Provide termination on all high-speed switching signals and clock lines.
• Provide impedance matching on long traces to prevent reflections.
• Route high-speed signals next to a continuous, unbroken ground plane.
• Filter and shield DC-DC converters, oscillators, etc.
• Do not route any digital signals between the LXT97x2 and the RJ-45 connectors at the edge of
the board.
• Do not extend any circuit power and ground plane past the center of the magnetics or to the
edge of the board. Use this area for chassis ground, or leave it void.
3.1.2
Power Supply Filtering
Power supply ripple and digital switching noise on the VCC plane can cause EMI problems and
degrade line performance. Minimize ground noise as much as possible using good general
techniques and by filtering the VCC plane. Predicting the noise performance of any design is
difficult, although certain factors greatly increase the risk of noise problems:
• Poorly-regulated or over-burdened power supplies
• Wide data busses (32-bits+) running at a high clock rate
• DC-to-DC converters
Intel recommends filtering the power supply to the analog VCC pins of the LXT97x2. This has
two benefits. First, prevents digital switching noise from affecting the analog circuitry inside the
LXT97x2, which helps line performance. Second, if the VCC planes are laid out correctly, it keeps
digital switching noise away from external connectors, reducing EMI problems.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Intel recommends dividing the VCC plane into two sections. The digital section supplies power to
the VCCD and VCCIO pins of the LXT97x2. The analog section supplies power to the VCCA
pins. The break between the two planes should run underneath the device. In designs with more
than one LXT97x2, a single continuous analog VCC plane can be used to supply them all.
The digital and analog VCC planes should be joined at one or more points by ferrite beads. The
beads should produce at least a 100Ω impedance at 100 MHz. Beads should be placed so that
current flow is evenly distributed. The maximum current rating of the beads should be at least
150% of the current that is actually expected to flow through them. A bulk cap (2.2 -10 µF) should
be place on each side of each bead.
In addition, a high-frequency bypass cap (.01µF) should be placed near each analog VCC pin.
3.1.3
Power and Ground Plane Layout Considerations
Take great care when laying out the power and ground planes. The following guidelines are
recommended:
• Follow the guidelines in the LXT97x2 Design & Layout Guide for locating the split between
the digital and analog VCC planes.
• Keep the digital VCC plane away from the TPFOP/N and TPFIP/N signals, away from the
magnetics, and away from the RJ-45 connectors.
• Place the layers so that the TPFOP/N and TPFIP/N signals can be routed near or next to the
ground plane. For EMI reasons, it is more important to shield TPFOP/N than TPFIP/N.
3.1.3.1
Chassis Ground
For ESD reasons, it is a good design practice to create a separate chassis ground that encircles the
board and is isolated via moats and keep-out areas from all circuit-ground planes and active
signals. Chassis ground should extend from the RJ45 connectors to the magnetics, and can be used
to terminate unused signal pairs (‘Bob Smith’ termination). In single-point grounding applications,
provide a single connection between chassis and circuit grounds with a 2 kV isolation capacitor. In
multi-point grounding schemes (chassis and circuit grounds joined at multiple points), provide 2
kV isolation to the Bob Smith termination.
3.1.4
3.1.5
MII Terminations
Series termination resistors are not required on the SMII signals driven by the LXT97x2.
The RBIAS Pin
The LXT97x2 requires a 22.1 kΩ, 1% resistor directly connected between the RBIAS pin and
ground. Place the RBIAS resistor as close to the RBIAS pin as possible. Run an etch directly from
the pin to the resistor, and sink the other side of the resistor to a filtered ground. Surround the
RBIAS trace with a filtered ground; do not run high-speed signals next to RBIAS.
3.1.6
The Twisted-Pair Interface
Follow standard guidelines for a twisted-pair interface:
• Keep transmit pair traces as short as possible; both traces should have the same length.
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
• Avoid vias and layer changes as much as possible.
• Keep the transmit and receive pairs apart to avoid cross-talk.
• Route the transmit pair adjacent to a ground plane. The optimum arrangement is to place the
transmit traces two to three layers from the ground plane, with no intervening signals.
• The output stage of the transmitter shown in Figure 24 on page 50 is designed to match the
100Ω characteristic impedance of an unshielded CAT5 twisted-pair wire. The external resistor
that is typically required for impedance matching is integrated in the transmitter of the
LXT97xx. The internal termination provides a constant current reference in both 10BASE-T
and 100BASE-TX applications and meets all IEEE transmitter requirements such as return
loss, while reducing external component requirements. It has no impact in fibre designs.
• Some magnetic vendors are producing magnetics with improved return loss performance. Use
of these improved magnetics increases the return loss budget available to the system designer.
• Improve EMI performance by filtering the TPO center tap. A single ferrite bead may be used
to supply center tap current to all ports. All ports draw a combined total of 520 mA so the
bead should be rated at 780 mA.
3.1.6.1
Magnetics Information
The LXT97x2 requires a 1:1 ratio for the receive transformers and a 1:1 ratio for the transmit
transformers. The transformer isolation voltage should be rated at 1.5 kV to protect the circuitry
from static voltages across the connectors and cables. Refer to Table 16 for transformer
requirements. Before committing to a specific component, designers should contact the
manufacturer for current product specifications, and validate the magnetics for the specific
application.
3.1.7
The Fiber Interface
The fiber interface consists of a PECL transmit and receive pair to an external fiber-optic
transceiver. The transmit and receive pair should be DC-coupled to the transceiver, and biased
appropriately. Refer to the fiber transceiver manufacturer’s recommendations for termination
circuitry. Figure 25 on page 51 shows a typical example.
Table 16. Magnetics Requirements
Parameter
Min
Nom
Max
Units
Test Condition
Rx turns ratio
Tx turns ratio
Insertion loss
–
–
1 : 1
1 : 1
0.6
–
–
–
–
–
0.0
350
–
1.1
–
dB
µH
kV
dB
dB
dB
dB
Primary inductance
Transformer isolation
1.5
–
–
Differential to common mode rejection
40
35
-16
-10
–
.1 to 60 MHz
–
–
60 to 100 MHz
30 MHz
–
–
Return Loss
–
–
80 MHz
48
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
3.2
Typical Application Circuits
Figure 24 shows a typical layout of the LXT97x2 twisted-pair interface in a dual-high (stacked)
RJ45 application.
Figure 23. Power and Ground Supply Connections
LXT97x2
GNDS
22.1k
Ω
1%
RBIAS
GNDA
.01µ
F
.01µF
VCCR
VCCT
10µF
+
Analog Supply Plane
Digital Supply Plane
Ferrite
Bead
10µF
+3.3V
VCCD
GNDD
VCCIO
.01µF
.01µF
+ 3.3V
Datasheet
49
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 24. Typical Twisted-Pair Interface
TPFOP
RJ45
1:1
1:1
1
2
3
4
5
6
7
8
1
TPFON
TPFIP
50
Ω
50
50
Ω
Ω
270 pF 5%
50Ω 1%
LXT97x1
2
50
50
Ω
Ω
50Ω 1%
50
Ω
TPFIN
270 pF 5%
0.01
3
* = 0.001 µF / 2.0 kV
µF
*
*
4
VCCT
GNDA
.01µF
0.1µF
5
1. The 100Ω transmit load termination resistor typically required is integrated in the LXT97xx.
2. Magnetics without a receive pair center-tap do not require a 2 kV termination.
3. Center tap current may be supplied from 3.3V VCCA as shown. However, additional power savings may be
realized by supplying the center-tap from from a 2.5V current source. In either case a single ferrite bead
(rated at 800 mA) may be used to supply center tap current to all ports.
4. Receive common mode bypass cap may improve BER performance in systems with noisy power supplies.
5. Recommended 0.1µF capacitor to improve the EMI performance.
50
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 25. Typical Fiber Interface
VCCD
+3.3V
16
Ω
Ω
0.1
GNDD
F
50
Ω
50
TPFONn
TPFOPn
TD-
TD+
VCCD
+3.3V
LXT97x2
Fiber Txcvr
130
Ω
SD/TPn
SD
VCCD
+3.3V
82
Ω
1
0.1
F
130
Ω
130 Ω
GNDD
GNDD
TPFINn
TPFIPn
RD-
RD+
82
Ω
82
GNDD
Ω
1. Refer to fiber transceiver manufacturer’s recommendations for termination circuitry.
Example shown above is suitable for HFBR5900-series devices.
Datasheet
51
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 26. Typical Serial LED Interface
595
activity(7)
595
rclk
collision(7)
collision(6)
collision(5)
collision(4)
collision(3)
collision(2)
collision(1)
collision(0)
LEDLATCH
rclk Qa
Qa
activity(6)
activity(5)
activity(4)
activity(3)
activity(2)
activity(1)
activity(0)
LEDLATCH
LXT9782
LEDCLK srclk
LEDCLK srclk
LEDS(0) ser
leds(4) ser
Qh
Qh
Qa
See Detail for LXT9761 configuration.
595
595
isopol(7)
receive(7)
receive(6)
receive(5)
receive(4)
receive(3)
receive(2)
receive(1)
receive(0)
Qa
isopol(6)
LEDLATCH rclk
LEDLATCH rclk
isopol(5)
isopol(4)
LEDCLK srclk
LEDCLK srclk
isopol(3)
isopol(2)
LEDS(1) ser
LEDS(5) ser
isopol(1)
Qh
isopol(0)
Qh
595
595
duplex(7)
transmit(7)
transmit(6)
transmit(5)
transmit(4)
transmit(3)
transmit(2)
transmit(1)
transmit(0)
Qa
duplex(6)
Qa
LEDLATCH rclk
LEDLATCH rclk
duplex(5)
duplex(4)
LEDCLK srclk
LEDCLK srclk
duplex(3)
duplex(2)
LEDS(2) ser
duplex(1)
LEDS(6) ser
Qh
Qh
duplex(0)
595
595
link(7)
speed(7)
speed(6)
speed(5)
speed(4)
speed(3)
speed(2)
speed(1)
speed(0)
Qa
Qa
link(6)
link(5)
link(4)
link(3)
link(2)
link(1)
link(0)
LEDLATCH rclk
LEDCLK srclk
LEDLATCH rclk
LEDCLK srclk
LEDS(3) ser
LEDS(7) ser
Qh
Qh
Alternate Configuration for LXT9762
595
activity(5)
LEDLATCH
rclk Qa
activity(4)
activity(3)
Not Used
Not Used
activity(2)
activity(1)
activity(0)
LEDCLK srclk
LEDS(0) ser
1. Note: The outputs are always enabled on the hc595 chips.
2. Ports 6 and 7 are not available on the LXT9762.
Serial outputs are re-mapped as shown in Detail at right.
Qh
52
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
4.0
Test Specifications
Table 17 through Table 34 and Figure 28 through Figure 39 represent the target specifications of
the LXT97x2. These specifications are guaranteed by test, except where noted “by design.”
Minimum and maximum values listed in Table 19 through Table 34 apply over the recommended
operating conditions specified in Table 18.
Table 17. Absolute Maximum Ratings
Parameter
Supply voltage
Sym
Min
Max
Units
VCC
TOPA
TOPC
TST
-0.3
-15
–
4.0
V
Operating temperature
Ambient
Case
+85
ºC
ºC
ºC
+120
+150
Storage temperature
-65
Caution: Exceeding these values may cause permanent damage.
Functional operation under these conditions is not implied.
Exposure to maximum rating conditions for extended periods may affect device reliability.
Table 18. Operating Conditions
1
Parameter
Sym
Min
Typ
Max
Units
Ambient
TOPA
TOPC
Vcca, Vccd
Vccio
ICC
0
0
–
–
70
122
3.45
3.45
140
140
–
ºC
ºC
Recommended operating temperature
Case4
Analog & Digital
I/O
3.15
3.15
–
3.3
V
Recommended supply voltage2
VCC current
–
V
100BASE-TX
100BASE-FX
10BASE-T
121
mA
mA
mA
mA
mA
ICC
–
–
ICC
–
–
–
Power Down Mode
Auto-Negotiation
ICC
–
–
ICC
–
114.53
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Voltages with respect to ground unless otherwise specified.
3. Per port @ 3.3V.
4. Environmental Condition - Natural convection (still air). Topc should be measured in the worst case thermal condition
(chassis, application, environment). If the Topc is greater than 122C, Air Flow (‘100 LFM) or heat sink (Attach: Thermoset
WP100 tape, 1”x1” square with a 0.75” diameter phase-change dot. Heat Sink: Thermally 31x31 mm-sq low profile, P/N
22370B must be added. Alternate thermal solutions may be used and/or required depending on specific system conditions.
Datasheet
53
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 19. Digital I/O Characteristics 1
2
Parameter
Input Low voltage3
Sym
Min
Typ
Max
Units
Test Conditions
VIL
VIH
II
–
2.0
-100
–
–
–
–
–
–
0.8
–
V
V
–
Input High voltage3
–
Input current
100
0.4
–
µA
V
0.0 < VI < VCC
IOL = 4 mA
IOH = -4 mA
Output Low voltage
Output High voltage
VOL
VOH
2.4
V
1. Applies to all pins except SMII pins. Refer to Table 20 for SMII I/O Characteristics.
2. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
3. Does not apply to REFCLK, QCLK or TCK. Refer to Table 21 for clock input levels.
Table 20. Digital I/O Characteristics - SMII Pins
1
Parameter
Input Low voltage
Sym
Min
Typ
Max
Units
Test Conditions
VIL
VIH
II
–
2.0
-100
–
–
–
0.8
–
V
V
–
–
Input High voltage
Input current
–
100
0.4
–
µA
V
0.0 < VI < VCC
Output Low voltage
VOL
VOH
VOH
–
IOL = 4 mA
2.2
2.0
–
–
V
IOH = -4 mA, VCC = 3.3V
IOH = -4 mA, VCC = 2.5V
VCC = 2.5V
Output High voltage
–
–
V
2
RO
100
100
–
Ω
Ω
Driver output resistance
(Line driver output enabled)
2
RO
–
–
VCC = 3.3V
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Parameter is guaranteed by design; not subject to production testing.
Table 21. Required REFCLK and SYNC Characteristics
1
Parameter
Input Low voltage
Sym
VIL
VIH
Trf
Min
–
Typ
–
Max
0.8
–
Units
V
Test Conditions
–
–
–
–
–
–
Input High voltage
2.0
–
–
V
Input rise/fall time
1
–
ns
REFCLK frequency
F
–
125
–
–
MHz
ppm
%
REFCLK clock frequency tolerance2
REFCLK clock duty cycle2
∆f
–
± 100
60
Tdc
40
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Parameter is guaranteed by design; not subject to production testing.
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 22. 100BASE-TX Transceiver Characteristics
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
Peak differential output voltage
Signal amplitude symmetry
Signal rise/fall time
VP
Vss
TRF
TRFS
0.95
98
–
–
–
–
1.05
102
5.0
V
Note 2
Note 2
Note 2
Note 2
%
ns
ns
3.0
–
Rise/fall time symmetry
0.5
Offset from 16ns pulse width at
50% of pulse peak
Duty cycle distortion
Overshoot
–
–
–
–
–
+/- 0.5
5
ns
%
VO
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Measured at the line side of the transformer, line replaced by 100Ω(+/-1%) resistor.
Table 23. 100BASE-FX Transceiver Characteristics
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
Note: Peak differential output
VOP
TRF
–
0.6
–
–
–
–
1.5
1.9
1.4
V
–
voltage (single ended)
Note: Signal rise/fall time
ns
ns
10 <–> 90% 2.0 pF load
Note: Jitter (measured
–
–
differentially)
Note: Peak differential input
VIP
0.55
–
–
1.5
V
V
–
–
voltage
Note: Common mode input range
VCMIR
–
VCC - 0.7
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Table 24. 10BASE-T Transceiver Characteristics
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
Peak differential output voltage
Link transmit period
VOP
2.2
8
2.5
2.8
24
V
Note 2
–
–
ms
–
Transmit timing jitter added by the
MAU and PLS sections 3, 4
–
0
2
11
ns
Note 5
Link min receive timer
Link max receive timer
Time link loss receive
TLRmin
TLRmax
TLL
2
50
50
–
4
7
ms
ms
–
64
150
150
–
–
64
ms
–
Differential squelch threshold
VDS
390
mV Peak
5 MHz square wave input
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Measured at the line side of the transformer, line replaced by 100Ω(+/-1%) resistor.
3. Parameter is guaranteed by design; not subject to production testing.
4. IEEE 802.3 specifies maximum jitter addition at 1.5 ns for the AUI cable, 0.5 ns from the encoder, and 3.5 ns from the MAU.
5. After line model specified by IEEE 802.3 for 10BASE-T MAU
Datasheet
55
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 27. MII Sync Timing
SYNC
t1 t2
REFCLK
Table 25. MII Sync Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
SYNC setup to REFCLK rising edge
SYNC delay from REFCLK rising edge
t1
t2
1.5
1
–
–
–
–
ns
ns
–
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 28. 100BASE-TX Receive Timing
REFCLK
t1
t
2
RXD
TPFI
Table 26. 100BASE-TX Receive Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
RXD setup from REFCLK rising edge
RXD Rise/Fall Time
t1
t2
–
2
–
–
–
–
3
5
–
–
–
ns
ns
See Figure 29
–
Receive start of /J/ to CRS asserted
Receive start of /T/ to CRS de-asserted
16
20
BT
BT
Synchronous sampling of SMII
Synchronous sampling of SMII
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
56
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 29. SMII Output Delay Test Setup
t1 measurement
1ns trace delay
RXD
DUT
LXT9762/82
1 CMOS Load ~ 6pF
Ref Clk
Figure 30. 100BASE-TX Transmit Timing
REFCLK
t
1
t
2
TXD
TPFO
Table 27. 100BASE-TX Transmit Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
TXD setup to REFCLK rising edge
TXD hold from REFCLK rising edge
TXEN sampled to start of /J/
t1
t2
–
1.5
1
–
–
–
–
–
ns
ns
–
–
–
12
BT
Synchronous sampling of SMII
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
57
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 31. 100BASE-FX Receive Timing
REFCLK
t1
t2
RXD
TPFI
Table 28. 100BASE-FX Receive Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
RXD setup from REFCLK rising edge
RXD Rise/Fall Time
t1
t2
–
2
–
–
–
–
3
5
–
–
–
ns
ns
See Figure 29
–
Receive start of /J/ to CRS asserted
Receive start of /T/ to CRS de-asserted
16
20
BT
BT
Synchronous sampling of SMII
Synchronous sampling of SMII
–
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Figure 32. 100BASE-FX Transmit Timing
REFCLK
t1
t
2
TXD
TPFO
Table 29. 100BASE-FX Transmit Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
TXD setup to REFCLK rising edge
TXD hold from REFCLK rising edge
TXEN sampled to start of /J/
t1
t2
–
1.5
1
–
–
–
–
–
ns
ns
–
–
–
12
BT
Synchronous sampling of SMII
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
58
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 33. 10BASE-T Receive Timing
REFCLK
RXD
t
1
t
2
TPFI
Table 30. 10BASE-T Receive Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
RXD setup from REFCLK rising edge
RXD Rise/Fall Time
t1
t2
–
2
–
–
–
–
3
5
–
–
–
ns
ns
See Figure 29
–
Receive Start-of-Frame to CRS asserted
Receive Start-of-Idle to CRS de-asserted
9
BT
BT
Synchronous sampling of SMII2
Synchronous sampling of SMII2
–
12
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Assumes each SMII segment is sampled for CRS.
Figure 34. 10BASE-T Transmit Timing
REFCLK
t1
t
2
TXD
TPFO
Table 31. 10BASE-T Transmit Timing Parameters
1
Parameter
Sym
Min
1.5
Typ
Max
Units
Test Conditions
TXD setup to REFCLK rising edge
TXD hold from REFCLK rising edge
TXEN sampled to Start-of-Frame
t1
t2
–
–
–
–
–
ns
ns
–
–
1
–
–
8
BT
Synchronous sampling of SMII
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
59
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 35. Auto-Negotiation and Fast Link Pulse Timing
Clock Pulse
Data Pulse
Clock Pulse
TPOP
t1
t1
t3
t2
Figure 36. Fast Link Pulse Timing
FLP Burst
FLP Burst
TPOP
t4
t5
Table 32. Auto-Negotiation and Fast Link Pulse Timing Parameters
1
Parameter
Clock/Data pulse width
Sym
Min
Typ
Max
Units
Test Conditions
t1
t2
t3
t4
t5
–
–
55.5
111
–
100
–
–
69.5
139
–
ns
µs
–
–
–
–
–
–
Clock pulse to Data pulse
Clock pulse to Clock pulse
FLP burst width
–
µs
2
ms
ms
ea
FLP burst to FLP burst
Clock/Data pulses per burst
8
–
24
17
–
33
1. Typical values are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
60
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Figure 37. MDIO Write Timing (MDIO Sourced by MAC)
MDC
t2
(Min)
t1
(Min)
MDIO
Figure 38. MDIO Read Timing (MDIO Sourced by PHY)
MDC
t3
MDIO
Table 33. MDIO Timing Parameters
1
Parameter
Sym
Min
10
1
Typ
–
Max
–
Units
Test Conditions
MDC = 2.5 MHz
MDC = 8 MHz
ns
ns
MDIO setup before MDC, sourced
by STA
t1
–
–
10
1
–
–
–
–
ns
ns
ns
ns
MDC = 2.5 MHz
MDC = 8 MHz
MDC = 2.5 MHz
MDC = 8 MHz
MDIO hold after MDC,
sourced by STA
t2
t3
10
1
–
300
–
MDC to MDIO output delay,
sourced by PHY
130
1. Typical values are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
Datasheet
61
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 39. Power-Up Timing
v1
t1
VCC
MDIO,etc
Table 34. Power-Up Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
Voltage threshold
Power Up delay
v1
t1
–
–
2.9
–
V
–
–
–
500
ms
1. Typical values are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
Figure 40. Reset and Power-Down Recovery Timing
t1
RESET
t2
MDIO,etc
Table 35. Reset and Power-Down Recovery Timing Parameters
1
Parameter
Sym
Min
Typ
Max
Units
Test Conditions
RESET pulse width
RESET recovery delay
t1
t2
10
–
–
–
ns
–
1
ms
1. Typical values are at 25° C and are for design aid only; not guaranteed and not subject to production testing.
62
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
5.0
Register Definitions
The LXT97x2 register set includes multiple 16-bit registers, 16 registers per port. Table 36 presents
a complete register listing. Table 37 is a complete memory map of all registers and Table 38
through Table 53 provide individual register definitions.
• Base registers (0 through 8) are defined in accordance with the “Reconciliation Sublayer and
Media Independent Interface” and “Physical Layer Link Signaling for 10/100 Mbps Auto-
Negotiation” sections of the IEEE 802.3 specification.
• Additional registers (16 through 22) are defined in accordance with the IEEE 802.3
specification for adding unique chip functions.
Table 36. Register Set
Address
Register Name
Bit Assignments
0
1
Control Register
Status Register
Refer to Table 38 on page 66
Refer to Table 39 on page 66
Refer to Table 40 on page 67
Refer to Table 41 on page 68
Refer to Table 42 on page 68
Refer to Table 43 on page 69
Refer to Table 44 on page 70
Refer to Table 45 on page 71
Refer to Table 46 on page 71
Not Implemented
2
PHY Identification Register 1
PHY Identification Register 2
Auto-Negotiation Advertisement Register
Auto-Negotiation Link Partner Base Page Ability Register
Auto-Negotiation Expansion Register
Auto-Negotiation Next Page Transmit Register
Auto-Negotiation Link Partner Next Page Receive Register
1000BASE-T/100BASE-T2 Control Register
1000BASE-T/100BASE-T2 Status Register
Extended Status Register
3
4
5
6
7
8
9
10
15
16
17
18
19
20
21-27
28
29
30
31
Not Implemented
Not Implemented
Port Configuration Register
Refer to Table 47 on page 72
Refer to Table 48 on page 72
Refer to Table 49 on page 73
Refer to Table 50 on page 74
Refer to Table 51 on page 75
Quick Status Register
Interrupt Enable Register
Interrupt Status Register
LED Configuration Register
Reserved
Transmit Control Register #1
Reserved
Refer to Table 52 on page 76
Refer to Table 53 on page 76
Transmit Control Register #2
Reserved
Datasheet
63
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
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Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Datasheet
65
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 38. Control Register (Address 0)
Bit
0.15
Name
Description
Type 1
Default
1 = PHY reset
0 = normal operation
R/W
SC
Reset
0
1 = enable loopback mode
0 = disable loopback mode
0.14
0.13
0.12
Loopback 2
R/W
R/W
R/W
0
0.6
0.13
1
1
0
0
1
0
1
0
= Reserved
= 1000 Mbps (not allowed)
= 100 Mbps
Note 3
00
Speed Selection
= 10 Mbps
Auto-Negotiation
Enable 4
1 = Enable Auto-Negotiation Process
0 = Disable Auto-Negotiation Process
Note 3
0
1 = power down
0 = normal operation
0.11
0.10
Power Down
Reserved
R/W
R/W
0
0
Write as zero. Ignore on read.
Restart
1 = Restart Auto-Negotiation Process
0 = normal operation
R/W
SC
0.9
0.8
Auto-Negotiation
1 = Full Duplex
0 = Half Duplex
Note 3
0
Duplex Mode
Collision Test
R/W
This bit is ignored by the LXT97x2.
R/W
0
0.7
1 = Enable COL signal test
0 = Disable COL signal test
0.6
0.13
1
1
0
0
1
0
1
0
= Reserved
= 1000 Mbps (not allowed)
= 100 Mbps
Speed Selection
1000 Mb/s
0.6
R/W
R/W
00
= 10 Mbps
0.5:0
Reserved
Write as 0, ignore on Read
00000
1. R/W = Read/Write
RO = Read Only
SC = Self Clearing
2. Internal Fiber Loopback Function is activated when the external SD/TP# pin for the port is pulled High.
3. Default value of bits 0.12, 0.13 and 0.8 are determined by hardware pins at Reset. Refer to Reset discussion on page 27.
4. Do not enable Auto-Negotiation if Fiber Mode is selected.
Table 39. Status Register (Address 1)
Bit
1.15
Name
100BASE-T4
Description
Type 1
Default
1 = PHY able to perform 100BASE-T4
0 = PHY not able to perform 100BASE-T4
RO
0
100BASE-X Full
Duplex
1 = PHY able to perform full-duplex 100BASE-X
0 = PHY not able to perform full-duplex 100BASE-X
1.14
1.13
RO
RO
1
1
100BASE-X Half
Duplex
1 = PHY able to perform half-duplex 100BASE-X
0 = PHY not able to perform half-duplex 100BASE-X
1. RO = Read Only
LL = Latching Low
LH = Latching High
2. Bit 1.4 is not valid if Auto-Negotiation is selected while operating in Fiber mode.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 39. Status Register (Address 1) (Continued)
Bit
1.12
Name
Description
Type 1
Default
1 = PHY able to operate at 10 Mbps in full-duplex mode
0 = PHY not able to operate at 10 Mbps full-duplex mode
10 Mbps Full Duplex
RO
1
1 = PHY able to operate at 10 Mbps in half-duplex mode
0 = PHY not able to operate at 10 Mbps in half-duplex
1.11
1.10
1.9
10 Mbps Half Duplex
RO
RO
RO
1
0
0
100BASE-T2 Full
Duplex
1 = PHY able to perform full-duplex 100BASE-T2
0 = PHY not able to perform full-duplex 100BASE-T2
100BASE-T2 Half
Duplex
1 = PHY able to perform half duplex 100BASE-T2
0 = PHY not able to perform half-duplex 100BASE-T2
1 = Extended status information in register 15
0 = No extended status information in register 15
1.8
1.7
Extended Status
Reserved
RO
RO
0
0
1 = ignore when read
1 = PHY will accept management frames with preamble
MF Preamble
Suppression
suppressed
1.6
RO
0
0 = PHY will not accept management frames with preamble
suppressed
Auto-Negotiation
complete
1 = Auto-negotiation complete
0 = Auto-negotiation not complete
1.5
1.4
1.3
1.2
1.1
1.0
RO
RO/LH
RO
0
0
1
0
0
0
1 = Remote fault condition detected
0 = No remote fault condition detected
Remote Fault2
Auto-Negotiation
Ability
1 = PHY is able to perform Auto-Negotiation
0 = PHY is not able to perform Auto-Negotiation
1 = Link is up
0 = Link is down
Link Status
RO/LL
RO/LH
RO
1 = Jabber condition detected
0 = Jabber condition not detected
Jabber Detect
Extended Capability
1 = Extended register capabilities
0 = Extended register capabilities
1. RO = Read Only
LL = Latching Low
LH = Latching High
2. Bit 1.4 is not valid if Auto-Negotiation is selected while operating in Fiber mode.
Table 40. PHY Identification Register 1 (Address 2)
Bit
Name
Description
Type 1
Default
PHY ID
Number
2.15:0
The PHY identifier composed of bits 3 through 18 of the OUI.
RO
0013 hex
1. RO = Read Only
Datasheet
67
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 41. PHY Identification Register 2 (Address 3)
Bit
Name
Description
Type 1
Default
The PHY identifier composed of bits 19 through 24 of
the OUI.
3.15:10
PHY ID number
RO
011110
Manufacturer’s
model number
001000 (LXT9762)
001011 (LXT9782)
3.9:4
3.3:0
6 bits containing manufacturer’s part number.
4 bits containing manufacturer’s revision number.
RO
RO
Manufacturer’s
revision number
XXXX
1. RO = Read Only
Figure 41. PHY Identifier Bit Mapping
a
1
r
s
x
b
2
c
Organizationally Unique Identifier
18 19
24
3
0
0
1
3
9
3
I/G
0
15
0
0
1
15
0
10
4
0
PHY ID Register #1 (Address 2)
PHY ID Register #2 (Address 3)
0
0
0
0
1
0
0
0
0
0
0
0
0
1
0
1
1
1
1
0
X
X
X
X
X
X
X
X
X
X
0
0
0
2
B
7
5
0
3
0
00
20
7B
Manufacturer’s
Model Number
Revision
Number
The Level One OUI is 00207B hex.
Table 42. Auto-Negotiation Advertisement Register (Address 4)
Bit
Name
Description
Type 1
Default
1 = Port has ability to send multiple pages.
0 = Port has no ability to send multiple pages.
4.15
4.14
4.13
4.12
4.11
Next Page
Reserved
R/W
RO
1
0
0
0
0
Ignore.
1 = Remote fault.
0 = No remote fault.
Remote Fault
Reserved
R/W
R/W
R/W
Ignore.
Asymmetric
Pause
Pause operation defined in Clause 40 and 27.
4.10
Pause
1 = Pause operation enabled for full-duplex links.
0 = Pause operation disabled.
R/W
Note 2
1. R/W = Read/Write
RO = Read Only
LHR = Latches High on Reset
2. The default setting of bit 4.10 (PAUSE) is determined by pin 79.
3. Default value of bits 4.8:5 are determined by hardware pins at Reset. Refer to Reset discussion on page 27.
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 42. Auto-Negotiation Advertisement Register (Address 4) (Continued)
Bit
Name
Description
Type 1
Default
4.9
100BASE-T4 1 = 100BASE-T4 capability is available.
0 = 100BASE-T4 capability is not available.
R/W
0
(The LXT97x2 does not support 100BASE-T4 but allows this bit
to be set to advertise in the Auto-Negotiation sequence for
100BASE-T4 operation. An external 100BASE-T4 transceiver
could be switched in if this capability is desired.)
4.8
100BASE-
TX
1 = Port is 100BASE-TX full duplex capable.
0 = Port is not 100BASE-TX full duplex capable.
R/W
Note 3
full-duplex
4.7
4.6
100BASE-
TX
1 = Port is 100BASE-TX capable.
0 = Port is not 100BASE-TX capable.
R/W
R/W
Note 3
Note 3
10BASE-T
full-duplex
1 = Port is 10BASE-T full duplex capable.
0 = Port is not 10BASE-T full duplex capable.
1 = Port is 10BASE-T capable.
4.5
10BASE-T
R/W
R/W
Note 3
00001
0 = Port is not 10BASE-T capable.
4.4:0
Selector
Field,
<00001> = IEEE 802.3.
<00010> = IEEE 802.9 ISLAN-16T.
S<4:0>
<00000> = Reserved for future Auto-Negotiation development.
<11111> = Reserved for future Auto-Negotiation development.
Unspecified or reserved combinations should not be transmitted.
1. R/W = Read/Write
RO = Read Only
LHR = Latches High on Reset
2. The default setting of bit 4.10 (PAUSE) is determined by pin 79.
3. Default value of bits 4.8:5 are determined by hardware pins at Reset. Refer to Reset discussion on page 27.
Table 43. Auto-Negotiation Link Partner Base Page Ability Register (Address 5)
Bit
5.15
Name
Description
Type 1
Default
1 = Link Partner has ability to send multiple pages.
0 = Link Partner has no ability to send multiple pages.
RO
0
Next Page
1 = Link Partner has received Link Code Word from LXT97x2.
0 = Link Partner has not received Link Code Word from the
LXT97x2.
5.14
Acknowledge
RO
0
1 = Remote fault.
0 = No remote fault.
5.13
5.12
Remote Fault
Reserved
RO
RO
0
0
Ignore.
Pause Operation defined in Clauses 40 and 27
Asymmetric
Pause
5.11
RO
0
1 = Link Partner is Asymmetric Pause capable.
0 = Link Partner is not Asymmetric Pause capable.
5.10
Pause
1 = Link Partner is Pause capable.
RO
0
0 = Link Partner is not Pause capable.
1. RO = Read Only
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 43. Auto-Negotiation Link Partner Base Page Ability Register (Address 5) (Continued)
Bit
5.9
Name
Description
Type 1
Default
1 = Link Partner is 100BASE-T4 capable.
0 = Link Partner is not 100BASE-T4 capable.
100BASE-T4
RO
0
100BASE-TX
full duplex
1 = Link Partner is 100BASE-TX full duplex capable.
0 = Link Partner is not 100BASE-TX full duplex capable.
5.8
5.7
RO
RO
0
0
1 = Link Partner is 100BASE-TX capable.
0 = Link Partner is not 100BASE-TX capable.
100BASE-TX
10BASE-T
full duplex
1 = Link Partner is 10BASE-T full duplex capable.
0 = Link Partner is not 10BASE-T full duplex capable.
5.6
5.5
RO
RO
0
0
1 = Link Partner is 10BASE-T capable.
0 = Link Partner is not 10BASE-T capable.
10BASE-T
<00001> = IEEE 802.3.
<00010> = IEEE 802.9 ISLAN-16T.
Selector Field
S<4:0>
5.4:0
<00000> = Reserved for future Auto-Negotiation development.
<11111> = Reserved for future Auto-Negotiation development.
Unspecified or reserved combinations shall not be transmitted.
RO
00000
1. RO = Read Only
Table 44. Auto-Negotiation Expansion (Address 6)
Bit
Name
Description
Type 1
Default
6.15:6
Reserved
Ignore on read.
RO
0
This bit indicates the status of the auto-negotiation variable, base page. It
flags synchronization with the auto-negotiation state diagram allowing
detection of interrupted links. This bit is only used if bit 16.1 (Alternate
Next Page feature) is set.
6.5
Base Page
RO
0
1 = base_page = true
0 = base_page = false
RO
LH
Parallel
1 = Parallel detection fault has occurred.
6.4
0
Detection Fault 0 = Parallel detection fault has not occurred.
Link Partner 1 = Link partner is next page able.
Next Page Able 0 = Link partner is not next page able.
6.3
6.2
RO
RO
0
1
1 = Local device is next page able.
Next Page Able
0 = Local device is not next page able.
1 = Indicates that a new page has been received as and the received code
word has been loaded into register 5 (base pages) or register 8 (next
Page Received pages) as specified in clause 28 of 802.3. This bit will be cleared on read.
If bit 16.1 is set, the Page Received bit will also be cleared when
RO
LH
6.1
6.0
0
0
mr_page_rx = false or transmit_disable = true.
Link Partner A/ 1 = Link partner is auto-negotiation able.
RO
N Able
0 = Link partner is not auto-negotiation able.
1. RO = Read Only
LH = Latching High
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Table 45. Auto-Negotiation Next Page Transmit Register (Address 7)
Name
Description
Type 1
Default
Bit
Next Page
1 = Additional next pages follow
7.15
R/W
RO
0
0
1
(NP)
0 = Last page
7.14
7.13
Reserved
Write as 0, ignore on read
Message Page
(MP)
1 = Message page
R/W
0 = Unformatted page
Acknowledge 2
(ACK2)
1 = Will comply with message.
7.12
7.11
R/W
R/W
0
0
0 = Can not comply with message.
1 = Previous value of the transmitted Link Code Word equalled logic
zero.
0 = Previous value of the transmitted Link Code Word equalled logic
one.
Toggle
(T)
Message/
Unformatted Code
Field
00000000
001
7.10:0
R/W
1. R/W = Read/Write
RO = Read Only
Table 46. Auto-Negotiation Link Partner Next Page Receive Register (Address 8)
Bit
Name
Description
Type 1
Default
Next Page
1 = Link Partner has additional next pages to send.
0 = Link Partner has no additional next pages to send.
8.15
RO
0
(NP)
Acknowledge
(ACK)
1 = Link Partner has received Link Code Word from LXT97x2.
0 = Link Partner has not received Link Code Word from LXT97x2.
8.14
8.13
8.12
RO
RO
RO
0
0
0
Message Page
(MP)
1 = Page sent by the Link Partner is a Message Page.
0 = Page sent by the Link Partner is an Unformatted Page.
Acknowledge 2
(ACK2)
1 = Link Partner will comply with the message.
0 = Link Partner can not comply with the message.
1 = Previous value of the transmitted Link Code Word equalled logic
zero.
0 = Previous value of the transmitted Link Code Word equalled logic
one.
Toggle
(T)
8.11
RO
RO
0
0
Message/
Unformatted Code
Field
8.10:0
1. RO = Read Only
Note: Registers 9, 10 and 15 are not implemented.
These registers only apply to 100BASE-T2 and 1000BASE-T, neither of which are supported by
this device.
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 47. Port Configuration Register (Address 16, Hex 10)
Bit
Name
Reserved
Description
This bit is ignored by the LXT97x2.
Type
Default
16.15
R/W
0
1 = Forces internal registers and state machines to Link Pass state.
0 = Normal operation.
16.14
16.13
Force Link Pass
Transmit Disable
R/W
R/W
0
0
1 = Disable Twisted-Pair transmitter.
0 = Normal Operation.
Bypass Scramble
(100BASE-TX)
1 = Bypass Scrambler and Descrambler.
0 = Normal Operation.
16.12
16.11
16.10
R/W
R/W
R/W
0
0
0
Reserved
This bit is ignored by the LXT97x2.
Jabber
(10BASE-T)
1 = Disable Jabber.
0 = Normal operation.
This bit is ignored by the LXT97x2.
SQE
(10BASE-T)
16.9
R/W
0
1 = Enable Heart Beat.
0 = Disable Heart Beat.
TP Loopback
(10BASE-T)
1 = Disable TP loopback during half duplex operation.
0 = Normal Operation.
16.8
16.7
R/W
R/W
1
0
Reserved
This bit is ignored by the LXT97x2.
0 = FIFO allows packets up to 2 KBytes.
1 = FIFO allows packets up to 8 KBytes.
16.6
FIFO Size
R/W
0
Note: This assumes a 100 ppm difference between the reference
clock and the recovered clock.
0 = Set RX_DV high coincident with SFD.
1 = Set RX_DV high and RXD=preamble when CRS is asserted.
16.5
Preamble Enable
R/W
0
16.4
16.3
Reserved
Reserved
Write as zero. Ignore on read.
Write as zero. Ignore on read.
R/W
R/W
0
0
Far End Fault
Transmit Enable
1 = Enable Far End Fault code transmission.
0 = Disable Far End Fault code transmission.
16.2
16.1
16.0
R/W
R/W
R/W
1
0
Alternate NP
feature
1 = Enable alternate auto-negotiate next page feature.
0 = Disable alternate auto-negotiate next page feature.
1 = Select fiber mode for this port.
0 = Select TP mode for this port.
Fiber Select
Note 2
1. R/W = Read /Write
2. The default value of bit 16.0 is determined at Reset by the SD/TPn pin for the respective port.
If SD/TPn is tied Low, the default value of bit 16.0 = 0. If SD/TPn is not tied Low, the default value of bit 16.0 = 1.
Refer to Reset discussion on page 27.
Table 48. Quick Status Register (Address 17, Hex 11)
Bit
Name
Reserved
Description
Type 1
RO
Default
17.15
Always 0
0
0
1 = LXT97x2 is operating in 100BASE-TX mode.
0 = LXT97x2 is not operating 100BASE-TX mode.
RO
17.14
17.13
10/100 Mode
1 = LXT97x2 is transmitting a packet
0 = LXT97x2 is not transmitting a packet
RO
0
Transmit Status
1. RO = Read Only
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Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
Table 48. Quick Status Register (Address 17, Hex 11) (Continued)
Bit
Name
Description
Type 1
Default
1 = LXT97x2 is receiving a packet
0 = LXT97x2 is not receiving a packet
17.12
Receive Status
RO
0
1 = Collision is occurring
0 = No collision
17.11
17.10
17.9
Collision Status
Link
RO
RO
RO
RO
0
0
0
0
1 = Link is up
0 = Link is down
1 = Full duplex
0 = Half duplex
Duplex Mode
Auto-Negotiation
1 = LXT97x2 is in Auto-Negotiation Mode
0 = LXT97x2 is in manual mode
17.8
1 = Auto-negotiation process completed
0 = Auto-negotiation process not completed
Auto-Negotiation
Complete
17.7
RO
0
This bit is only valid when auto-negotiate is enabled, and is equivalent
to bit 1.5.
17.6
17.5
Reserved
Polarity
Ignore
RO
RO
0
0
1= Polarity is reversed
0= Polarity is not reversed
1 = LXT97x2 is Pause capable
0 = LXT97x2 is not Pause capable
17.4
Pause
RO
This bit is equivalent to bit 4.10.
1 = Error occurred (Remote Fault, X,Y,Z)
0 = No error occurred
17:3
Error
RO
RO
0
0
17:2:0
Reserved
Ignore
1. RO = Read Only
Table 49. Interrupt Enable Register (Address 18, Hex 12)
Bit
Name
Description
Type 1
Default
18.15:8 Reserved
Write as 0; ignore on read.
R/W
N/A
Mask for Auto-Negotiate Complete
18.7
18.6
18.5
ANMSK
R/W
R/W
R/W
0
0
0
1 = Enable event to cause interrupt
0 = Do not allow event to cause interrupt
Mask for Speed Interrupt
SPEEDMSK
DUPLEXMSK
1 = Enable event to cause interrupt
0 = Do not allow event to cause interrupt
Mask for Duplex Interrupt
1 = Enable event to cause interrupt
0 = Do not allow event to cause interrupt
Mask for Link Status Interrupt
18.4
18.3
LINKMSK
Reserved
R/W
R/W
0
0
1 = Enable event to cause interrupt
0 = Do not allow event to cause interrupt
Write as 0, ignore on read.
1. R/W = Read /Write
Datasheet
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 49. Interrupt Enable Register (Address 18, Hex 12) (Continued)
Bit
18.2
18.1
Name
Description
Type 1
R/W
R/W
Default
Reserved
Write as 0, ignore on read.
0
0
INTEN
1 = Enable interrupts on this port.
0 = Disable interrupts on this port.
18.0
TINT
1 = Force interrupt on MDINT.
0 = Normal operation
R/W
0
1. R/W = Read /Write
Table 50. Interrupt Status Register (Address 19, Hex 13)
Bit
Name
Description
Type 1
Default
19.15:8 Reserved
Ignore
RO
N/A
Auto-Negotiation Status
19.7
19.6
ANDONE
RO/SC
RO/SC
N/A
0
1= Auto-Negotiation has completed
0= Auto-Negotiation has not completed
Speed Change Status
SPEEDCHG
1 = A Speed Change has occurred since last reading this register
0 = A Speed Change has not occurred since last reading this register
Duplex Change Status
19.5
19.4
DUPLEXCHG
LINKCHG
1 = A Duplex Change has occurred since last reading this register
0 = A Duplex Change has not occurred since last reading this register
RO/SC
RO/SC
0
Link Status Change Status
1 = A Link Change has occurred since last reading this register
0 = A Link Change has not occurred since last reading this register
0
0
19.3
Reserved
MDINT
Ignore
RO/SC
RO/SC
RO
1 = Indicates MII interrupt pending
0 = Indicates no MII interrupt pending
19.2
19.1:0
Reserved
Ignore
0
1. R/W = Read/Write
RO = Read Only
SC = Self Clearing when read.
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Table 51. LED Configuration Register (Address 20, Hex 14)
Bit
Name
Description
Type 1
Default
0000 = Display Speed Status (Continuous, Default)
0001 = Display Transmit Status (Stretched)
0010 = Display Receive Status (Stretched)
0011 = Display Collision Status (Stretched)
0100 = Display Link Status (Continuous)
0101 = Display Duplex Status (Continuous)5
0110 = Reserved
LED1
0111 = Display Receive or Transmit Activity (Stretched)
1000 = Test mode- turn LED on (Continuous)
1001 = Test mode- turn LED off (Continuous)
1010 = Test mode- blink LED fast (Continuous)
1011 = Test mode- blink LED slow (Continuous)
1100 = Display Link and Receive Status combined 2 (Stretched)3
1101 = Display Link and Activity Status combined 2 (Stretched)3
1110 = Display Duplex and Collision Status combined 4 (Stretched)3,5
1111 = Reserved
20.15:12
R/W
0000
Programming
bits
0000 = Display Speed Status (Continuous, Default)
0001 = Display Transmit Status (Stretched)
0010 = Display Receive Status (Stretched)
0011 = Display Collision Status (Stretched)
0100 = Display Link Status (Continuous)
0101 = Display Duplex Status (Continuous)5
0110 = Reserved
LED2
0111 = Display Receive or Transmit Activity (Stretched)
1000 = Test mode- turn LED on (Continuous)
1001 = Test mode- turn LED off (Continuous)
1010 = Test mode- blink LED fast (Continuous)
1011 = Test mode- blink LED slow (Continuous)
1100 = Display Link and Receive Status combined 2 (Stretched)3
1101 = Display Link and Activity Status combined 2 (Stretched)3
1110 = Display Duplex and Collision Status combined 4 (Stretched)3,5
1111 = Reserved
20.11:8
R/W
0100
Programming
bits
0000 = Display Speed Status (Continuous, Default)
0001 = Display Transmit Status (Stretched)
0010 = Display Receive Status (Stretched)
0011 = Display Collision Status (Stretched)
0100 = Display Link Status (Continuous)
0101 = Display Duplex Status (Continuous)5
0110 = Reserved
LED3
0111 = Display Receive or Transmit Activity (Stretched)
1000 = Test mode- turn LED on (Continuous)
1001 = Test mode- turn LED off (Continuous)
1010 = Test mode- blink LED fast (Continuous)
1011 = Test mode- blink LED slow (Continuous)
1100 = Display Link and Receive Status combined 2 (Stretched)3
1101 = Display Link and Activity Status combined 2 (Stretched)3
1110 = Display Duplex and Collision Status combined 4 (Stretched)3,5
1111 = Reserved
20.7:4
R/W
0010
Programming
bits
1. R/W = Read /Write
RO = Read Only
LH = Latching High
2. Link status is the primary LED driver. The LED is asserted (solid ON) when the link is up.
The secondary LED driver (Receive or Activity) causes the LED to change state (blink).
3. Combined event LED settings are not affected by Pulse Stretch bit 20.1. These display settings are stretched regardless of
the value of 20.1.
4. Duplex status is the primary LED driver. The LED is asserted (solid ON) when the link is full duplex.
Collision status is the secondary LED driver. The LED changes state (blinks) when a collision occurs.
5. Duplex LED may be active for a brief time after loss of link.
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LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Table 51. LED Configuration Register (Address 20, Hex 14) (Continued)
Bit
Name
Description
Type 1
Default
00 = Stretch LED events to 30 ms
01 = Stretch LED events to 60 ms
10 = Stretch LED events to 100 ms
11 = Reserved
20.3:2
LEDFREQ
R/W
00
PULSE-
STRETCH
0 = Disable pulse stretching of all LEDs
1 = Enable pulse stretching of all LEDs
20.1
20.0
R/W
R/W
1
0
Reserved
1. R/W = Read /Write
RO = Read Only
LH = Latching High
2. Link status is the primary LED driver. The LED is asserted (solid ON) when the link is up.
The secondary LED driver (Receive or Activity) causes the LED to change state (blink).
3. Combined event LED settings are not affected by Pulse Stretch bit 20.1. These display settings are stretched regardless of
the value of 20.1.
4. Duplex status is the primary LED driver. The LED is asserted (solid ON) when the link is full duplex.
Collision status is the secondary LED driver. The LED changes state (blinks) when a collision occurs.
5. Duplex LED may be active for a brief time after loss of link.
Table 52. Transmit Control Register #1 (Address 28)
Bit
Name
Description
Type
Default
28.12:4
Reserved
Ignore.
R/W
N/A
00 = Nominal Differential Amp Bandwidth
Bandwidth
Control
01 = Slower
10 = Fastest
11 = Faster
28.3:2
28.1:0
R/W
R/W
00
00 = 2.5ns
01 = 3.1ns
10 = 3.7ns
11 = 4.3ns
Risetime
Control
Note 2
1. RO = Read Only.
R/W = Read/Write.
2. The default setting of bits 28.1:0 (Risetime) is determined by pins 91 and 94 TxSLEW<1:0>.
Table 53. Transmit Control Register #2 (Address 30)
Bit
Name
Reserved
Description
Type
Default
30.15:14
R/W
R/W
R/W
N/A
1 = Increase Driver Amplitude 5% in all modes.
0 = Normal operation.
Increase Driver
Amplitude
30.13
0
30.12:0
Reserved
N/A
1. RO = Read Only.
76
Datasheet
Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII — LXT9762/9782
6.0
Package Specifications
Figure 42. LXT97x2 PQFP Package Specification
208-Pin Plastic Quad Flat Package
•
•
•
Part Number LXT9762HC (6-port model)
Part Number LXT9782HC (8-port model)
Commercial Temperature Range (0°C to 70°C)
D
Millimeters
Max
D1
Dim
Min
A
A1
A2
b
-
4.10
-
0.25
e
3.20
3.60
0.27
30.90
28.30
30.90
28.30
E1
E
0.17
e
/
D
30.30
27.70
30.30
27.70
2
D
1
E
E
1
e
.50 BASIC
1.30 REF
θ2
L
0.50
0.75
L1
L
1
A2
A
q
0°
5°
5°
7°
θ
θ
16°
16°
2
3
A1
θ3
θ
b
L
Datasheet
77
LXT9762/9782 — Fast Ethernet 10/100 Multi-Port Transceiver with Serial MII
Figure 43. LXT97x2 PBGA Package Specification
272-Lead Plastic Ball Grid Array
•
•
Part Number LXT9782BC (8-port model)
Commercial Temperature Range (0°C to 70°C)
24.13
1.435 REF
1.27
A
B
C
D
E
F
27.00 ±0.20
24.00 ±0.20
0.75
±0.15
8.00 ±0.10
PIN #A1
CORNER
1.27
G
H
J
PIN #A1 ID
8.00 ±0.10
K
L
24.13
27.00 ±0.20
M
N
P
R
T
24.00 ±0.20
U
V
W
Y
Ø1.00
(3 plcs)
TOP VIEW
20 19
18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2 1
1.435 REF
BOTTOM VIEW
2.13
0.92
± 0.19
NOTE:
± 0.05
1. ALL DIMENSIONS IN MILLIMETERS
2. ALL DIMENSIONS AND TOLERANCES
CONFORM TO ASME Y 14.5M-1994
3. TOLERANCE = ± 0.05 UNLESS
SPECIFIED OTHERWISE
0.61
±0.04
0.60
± 0.10
SEATING PLANE
SIDE VIEW
78
Datasheet
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