Intel PCI User Manual

227

SPEED 7:6

X

Link speed setting 
Indicates the configured speed of the link.
These bits are either forced by software when forcing the link 
speed through the CTRL.SPEED control bits, automatically set 
by hardware when Auto-Speed Detection is enabled or reflect 
the internal indication inputs from the PHY. 
When Auto-Speed Detection is enabled, the Ethernet 
controller’s speed is configured only once after the internal link 
is asserted.
Speed indication is mapped as follows:
00b = 10 Mb/s
01b = 100 Mb/s
10b = 1000 Mb/s
11b = 1000 Mb/s
These bits are not valid in TBI mode/internal SerDes.

ASDV

9:8

X 

Auto Speed Detection Value
Indicates the speed sensed by the Ethernet controller from the 
internal PHY. The ASDV status bits are provided for diagnostics 
purposes. The ASD function can be initiated by software writing 
a logic 1b to the CTRL_EXT.ASDCHK bit. The resultant speed 
detection is reflected in these bits. See 

 for 

details.

Reserved

10

X

Reserved
Reads as 0b.

PCI66

11

X

PCI Bus speed indication
When set, indicates that the PCI bus is running at 66 MHz. 
Reflects the M66EN input pin.
Note: Not applicable to the 82547GI/EI.

BUS64

1

12

X

PCI Bus Width indication
When set, indicates that the Ethernet controller is sitting on a 
64-bit PCI/PCI-X bus. BUS64 is determined by REQ64# 
assertion.

PCIX_MODE

1

13

X

PCI-X Mode indication
When set to 1b, the Ethernet controller is operating in PCI-X 
Mode; otherwise, the Ethernet controller is operating in 
conventional PCI Mode.

PCIXSPD

1

15:14

X

PCI-X Bus Speed Indication
Attempts to indicate the speed of the bus when operating in a 
PCI-X bus. Only valid when STATUS.PCIX_Mode = 1b.
00b = 50-66 MHz
01b = 66-100 MHz
10b = 100-133 MHz
11b = Reserved

Reserved

31:16

0b

Reserved
Reads as 0b.

1.

Not applicable to the 82540EP/EM, 82541xx, or 82547GI/EI.