Register Descriptions

Table 13-16. PHY Control Register Bit Description

Field

Bit(s)

Description

Mode

HW Rst

SW Rst

 

 

 

 

 

 

 

 

1b = Power down.

 

 

 

 

 

0b = Normal operation.

 

 

 

 

 

Power down shuts down the Ethernet

 

 

 

 

 

controller except for the MAC interface if

 

 

 

 

 

the MAC interface power down bit is set

 

 

 

 

 

to 1b. If it equals 0b, then the MAC

 

 

 

 

 

interface also shuts down. For the

 

 

 

 

 

82544GC/EI, power down has no effect

 

 

 

 

 

on the 125CLK output if the Disable

 

 

 

 

 

125CLK bit is set to 0b.

 

 

 

 

 

NOTE: Setting this bit to 1b will prevent

 

 

 

 

 

wakeup by detecting circuitry

 

 

 

Power Down

11

on the CAT5 cable. To enable

R/W

0b

0b

wakeup, this bit must be written

 

 

 

 

 

 

 

back to 0b.

 

 

 

 

 

82544GC/EI only:

 

 

 

 

 

If bit 12 is set to 0b and speed is

 

 

 

 

 

manually forced to 1000 Mb/s in bits 13

 

 

 

 

 

and 6, then Auto-Negotiation is still

 

 

 

 

 

enabled and only 1000BASE-T full

 

 

 

 

 

duplex is advertised if bit 8 is set to 1b.

 

 

 

 

 

1000BASE-T half duplex is advertised if

 

 

 

 

 

bit 8 is cleared (0b). Duplex settings in

 

 

 

 

 

other registers are ignored. Auto-

 

 

 

 

 

Negotiation is required by IEEE for

 

 

 

 

 

proper operation in 1000BASE-T.

 

 

 

 

 

 

 

 

 

242

Software Developer’s Manual

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Intel PCI-X, Intel Gigabit Ethernet Controllers manual 242