W89C940 Datasheet, PDF (16/61 Pages) Winbond – ELANC-PCI (TWISTED-PAIR ETHER-LAN CONTROLLER WITH PCI INTERFACE)

W89C940
PCI Bus Operation Configuration Registers
The W89C940 implement a system configuration registers for PCI bus auto configuration function. The
W89C940 support the predefined header portion of the system configuration space ( i.e. first 64 bytes of the
256 bytes configuration space). A summarized table for those registers is as following.
address of
configuration
space
01H~00H
03H~02H
05H~04H
07H~06H
08H
0BH~09H
0CH
0DH
0EH
0FH
13H~10H
17H~14H
1BH~18H
1FH~1CH
23H~20H
27H~24H
2BH~28H
2FH~2CH
33H~30H
37H~34H
3BH~38H
3CH
3DH
3EH
3FH
Register
Vendor-ID
Device-ID
Command
Status
Revision-ID
Class-Code
Cache-Line-Size
Latency-Timer
Header-Type
BIST
I/O-Base-Address
Reserved-Reg.-0
Reserved-Reg.-1
Reserved-Reg.-2
Reserved-Reg.-3
Reserved-Reg.-4
Reserved-Reg.-5
Reserved-Reg.-6
ROM-Base-Address
Reserved-Reg.-7
Reserved-Reg.-8
Interrupt Line
Interrupt Pin
Min-Gnt
Max-Lat
Attribute Default Value Write By
after power ON
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
R/W
R
R
R
R
R
R
R
R/W
R
R
R/W
R
R/W
R/W
1050H
5A5AH
0000H
0280H
00H
020000H
00H
00H
00H
00H
FFFFFFE1H
00000000H
00000000H
00000000H
00000000H
00000000H
00000000H
00000000H
FFFF8001H
00000000H
00000000H
00H
01H
00H
00H
EEPROM
EEPROM
System S/W
System S/W
EEPROM
None
None
None
None
None
System S/W
None
None
None
None
None
None
None
System S/W
None
None
System S/W
None
EEPROM
EEPROM
The vendor ID, device ID, revision ID, Min-Gnt and Max-Lat are programmed by EEPROM, i.e. the contents of
these register can be updated by EEPROM load only. The I/O base address and the ROM base address
registers can be updated by system software. Those system configuration registers should be accessed by a
double word access operation. The W89C940 will drive 32 bits data on the bus when these configuration
registers are accessed.
Vendor ID Register
The vendor I.D. identifies the manufacturer of the device. Valid vendor identifiers are allocated by the PCI SIG
to ensure uniqueness. The content of this register will be updated after power on by the EEPROM load
operation. The vendor ID should be programmed into the word with 09H address of the EEPROM for power on
auto loading.
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