74740-0001 Datasheet, PDF (7/11 Pages) Molex Electronics Ltd. – 1000Base-T RJ-45 Gigabit Ethernet GBIC Copper Transceiver

AUTO-NEGOTIATION SOFTWARE SELECTIONS
1000Base-T RJ-45 Gigabit
Ethernet GBIC Copper
Transceiver
Through random I2C read commands, the host can change the auto-negotiation state of the GBIC. When auto-negotiation in the GBIC is
off, the GBIC does not automatically query the host and advertise pause flow control on the copper interface. If the host requires
advertisement of pause flow control and auto-negotiation is off, the host can set pause, and asymmetric pause using the defined I2C
commands. Serial ID addresses 128-133 are used in the random I2C read commands. The read commands, and GBIC actions are defined
in the I2C Command Table.
I2C Command Table
I2C Read Address
De s cr iption
GBIC Actions
128 ( 0x80 )
129 ( 0x81 )
130 ( 0x82 )
131 ( 0x83 )
132 ( 0x84 )
133 ( 0x85 )
GBIC Auto-Negotiation Status
•
•
Enable Auto-Negotiation
•
•
•
Disable Auto-Negotiation
•
•
•
Clear SERDES Pause Flow Control Advertisement •
•
SERDES Pause Flow Control Advertisement •
(auto-negotiation off only)
•
SERDES Asymmetric Pause Flow Control
•
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(auto-negotiation off only)
•
Return Status Byte
Turn Auto-Negotiation ON
Restart Auto-Negotiation
Return Status Byte
Turn Auto-Negotiation OFF
Restart Auto-Negotiation
Return Status Byte
Clear Pause Flow Control
Clear Asymmetric Pause
Return Status Byte
Set SERDES Pause Flow Control Bit
Return Status Byte
Set SERDES Asymmetric Pause Flow Control Bit
Return Status Byte
GBIC Status Byte
Bit Description
7
Reserved
6
Reserved
5
Reserved
4
Copper has Advertised Asymmetric Pause
3
Copper has Advertised Pause
2
Host to Advertise Asymmetric Pause on Copper
1
Host to Advertise Pause on Copper
0
GBIC Auto Negotiation Status 1 = On / 0 = Off