DS80PCI800SQ Datasheet, PDF (23/45 Pages) Texas Instruments – DS80PCI800 2.5 Gbps / 5.0 Gbps / 8.0 Gbps 8 Channel PCI Express Repeater

DS80PCI800
www.ti.com
SNLS334E – APRIL 2011 – REVISED MARCH 2012
1. The Host drives a START condition, the 7-bit SMBus address, and a “0” indicating a WRITE.
2. The Device (Slave) drives the ACK bit (“0”).
3. The Host drives the 8-bit Register Address.
4. The Device drives an ACK bit (“0”).
5. The Host drives a START condition.
6. The Host drives the 7-bit SMBus Address, and a “1” indicating a READ.
7. The Device drives an ACK bit “0”.
8. The Device drives the 8-bit data value (register contents).
9. The Host drives a NACK bit “1”indicating end of the READ transfer.
10. The Host drives a STOP condition.
The READ transaction is completed, the bus goes IDLE and communication with other SMBus devices may now
occur.
Please see SMBus Register Map Table for more information.
Address
0x00
0x01
0x02
0x05
0x06
Table 9. SMBUS Slave Mode Register Map
Register Name
Observation,
Reset
Bit (s) Field
7
Reserved
6:3 Address Bit
AD[3:0]
PWDN Channels
2
EEPROM Read
Done
1
Block Reset
0
Reset
7:0 PWDN CHx
Override
7:1
PRSNT Control
0
Slave Mode CRC Bits 7:0
Slave CRC Control 7:5
4
3
Reserved
Override PRSNT
CRC bits
Reserved
Reserved
Slave CRC
2:0 Reserved
Type
R/W
R
Default
0x00
R
R/W
R/W
R/W 0x00
R/W 0x00
R/W 0x00
R/W 0x10
Description
Set bit to 0.
Observation of AD[3:0] bit
[6]: AD3
[5]: AD2
[4]: AD1
[3]: AD0
1: Device completed the read from external
EEPROM.
1: Block bit 0 from resettting the registers; self
clearing.
SMBus Reset
1: Reset registers to default value; self clearing.
Power Down per Channel
[7]: CH7 – CHA_3
[6]: CH6 – CHA_2
[5]: CH5 – CHA_1
[4]: CH4 – CHA_0
[3]: CH3 – CHB_3
[2]: CH2 – CHB_2
[1]: CH1 – CHB_1
[0]: CH0 – CHB_0
00'h = all channels enabled
FF'h = all channels disabled
Note: override PRSNT pin.
Set bits to 0.
1: Block PRSNT pin control
0: Allow PRSNT pin control
CRC bits [7:0]
Set bits to 0.
Set bit to 1.
1: Disables the slave CRC mode
0: Enables the slave CRC mode
Note: In order to change VOD, DEM and EQ of the
channels in slave mode, set bit to 1 to disable the
CRC.
Set bits to 0.
Copyright © 2011–2012, Texas Instruments Incorporated
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