Intel PCI User Manual

Page of 406
234
Software Developer’s Manual
Register Descriptions
SDP6_IODIR
SDP2_IODIR 
(82541xx and 
82547GI/EI)
10
0b
1
SDP6[2] Pin Directionality. Controls whether software-controllable 
pin SDP6[2] is configured as an input or output (0b = input, 1b = 
output). Initial value is EEPROM-configurable. This bit is not 
affected by software or system reset, only by initial power-on or 
direct software writes.
SDP7_IODIR
SDP2_IODIR 
(82541xx and 
82547GI/EI)
11
0b
1
SDP7[2] Pin Directionality. Controls whether software-controllable 
pin SDP7[2] is configured as an input or output (0b = input, 1b = 
output). Initial value is EEPROM-configurable. This bit is not 
affected by software or system reset, only by initial power-on or 
direct software writes.
ASDCHK
12
0b
ASD Check
Initiate an Auto-Speed-Detection (ASD) sequence to sense the 
frequency of the PHY receive clock. The results are reflected in 
STATUS.ASDV. This bit is self-clearing.
This functionality is provided for diagnostic purposes, regardless of 
whether the Auto Speed Detection feature is enabled. This bit is 
applicable only for internal PHY mode of operation.
EE_RST
13
0b
EEPROM Reset
When set, initiates a reset-like event to the EEPROM function. This 
causes the EEPROM to be read as if a RST# assertion had 
occurred. All device functions should be disabled prior to setting 
this bit. This bit is self-clearing.
Reserved
14
0b
1
Reserved. Should be set to 0b.
SPD_BYPS
15
0b
Speed Select Bypass
When set to 1b, all speed detection mechanisms are bypassed, 
and the Ethernet controller is immediately set to the speed 
indicated by CTRL.SPEED. This can be used to override the 
hardware clock switching circuitry and give full control to software. 
SPD_BYPS differs from the CTRL.FRCSPD function in that 
FRCSPD uses the internal clock switching circuitry rather than an 
immediate forcing function of the speed settings, as does 
SPD_BYPS.
Reserved
16
0b
1
Reserved. Should be set to 0b.
RO-DIS
17
0b
Relaxed Ordering Disabled
When set to 1b, the Ethernet controller does not request any 
relaxed ordering transactions in PCI-X mode regardless of the 
state of bit 1 in the PCI-X command register. When this bit is clear 
and bit 1 of the PCI-X command register is set, the Ethernet 
controller requests relaxed ordering transactions.
Note: This is a reserved bit for the 82540EP/EM82541xx, and 
82547GI/EI. Set to 0b.
Reserved
20:18
0b
Reserved
Should be written with 0b to ensure future compatibility.
Reads as 0b.
Field
Bit(s)
Initial 
Value
Description