AM79C976 datasheet(170/309 Pages) AMD

170 / 309 page

170

Am79C976

8/01/00

P R E L I M INARY

SVID_A: PCI Subsystem Vendor ID Alias Register

Offset 1B6h

This register is a writable alias of the Subsystem Ven-

dor ID field at offset 2Ch in PCI configuration space,

which is read only. The purpose of this register is to

allow the PCI Subsystem Vendor ID value to be loaded

from the serial EEPROM.

The contents of this register are cleared to 0 when the

RST pin is asserted, before the serial EEPROM is

read, and after a serial EEPROM read error.

Table 80. SVID: PCI Subsystem Vendor ID Shadow Register

TEST0: Test Register

Offset 1A8h

This register is used for factory test purposes only. All

bits must be zero for normal operation.

Table 81. TEST0: Test Register

Bit

Name

Description

15-0

SVID

Subsystem Vendor ID. SVID is used together with the PCI Subsystem ID Register to uniquely

identify the add-in board or subsystem the Am79C976 controller is used in. Subsystem Vendor IDs

can be obtained form the PCI SIG. A value of 0 (the default) indicates that the Am79C976 controller

does not support subsystem identification. SVID is aliased to the PCI configuration space register

Subsystem Vendor ID (offset 2Ch).

This register is an alias of BCR23 and of the PCI configuration space Subsystem Vendor

ID field at offset 2Ch.

Bit

Name

Description

31:18

RES

Factory test bits; must be 0 for normal operation.

CBIO_EN