Programming 33
Table 3-6 PCI Class Code Register
PCI Class Code: Offset $09
Bit
Description
Read
Write
Value after
PCI Reset
7:0
Register Level Programming Interface.
None defined.
Yes
No
$0
15:8
Subclass Code
Yes
No
$80
23:16
Base Class Code
Yes
No
$02
Base Class Code of $02 equals Network Controller. Subclass Code of $80 equals other network controller.
Table 3-7 PCI Cache Line Size Register
PCI Cache Line Size: Offset $0C
Bit
Description
Read
Write
*Value after
PCI Reset
7:0
System Cache Line Size.
Not applicable to PCI Express.
Yes
Yes
$0
*
NOTE:
This register can be altered by the system BIOS during the system boot process.
Table 3-8 PCI Latency Timer Register
PCI Latency Timer: Offset $0D
Bit
Description
Read
Write
*Value after
PCI Reset
7:0
PCI Bus Latency Timer
. Not applicable to PCI Express.
Yes
Yes
$00
*
NOTE:
This register can be altered by the system BIOS during the system boot process.
Table 3-9 PCI Header Type Register
PCI Header Type: Offset $0E
Bit
Description
Read
Write
Value after
PCI Reset
6:0
Configuration Layout Type.
Specifies layout of bits $10
through $3F in Configuration Space. Only one encoding, $0,
is defined. All other encodings are reserved.
Yes
No
$0
7
Header Type.
Writing a one (1) indicates multiple functions.
Writing a zero (0) indicates single function.
Yes
No
0