Datasheet

4−15

4.26 Subsystem Vendor ID Register

The subsystem vendor ID register is used for system and option-card identification purposes and may be required

for certain operating systems. This register is read-only or read/write, depending on the setting of bit 5 (SUBSYSRW)

in the system control register (PCI offset 80h, see Section 4.29).

Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Name Subsystem vendor ID

Type R R R R R R R R R R R R R R R R

Default 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Offset: 40h (functions 0, 1)

Type: Read-only (Read/Write if enabled by SUBSYSRW)

Default: 0000h

4.27 Subsystem ID Register

The subsystem ID register is used for system and option-card identification purposes and may be required for certain

operating systems. This register is read-only or read/write, depending on the setting of bit 5 (SUBSYSRW) in the

system control register (PCI offset 80h, see Section 4.29).

Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Name Subsystem ID

Type R R R R R R R R R R R R R R R R

Default 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Offset: 42h (functions 0, 1)

Type: Read-only (Read/Write if enabled by SUBSYSRW)

Default: 0000h

4.28 PC Card 16-Bit I/F Legacy-Mode Base Address Register

The PCI1520 supports the index/data scheme of accessing the ExCA registers, which are mapped by this register.

An address written to this register is the address for the index register and the address + 1 is the data address. Using

this access method, applications requiring index/data ExCA access can be supported. The base address can be

mapped anywhere in 32-bit I/O space on a word boundary; hence, bit 0 is read-only, returning 1 when read. As

specified in the PCI to PCMCIA CardBus Bridge Register Description (Yenta), this register is shared by functions 0

and 1. See Section 5, ExCA Compatibility Registers, for register offsets.

Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

Name PC Card 16-bit I/F legacy-mode base address

Type RW RW RW RW RW RW RW RW RW RW RW RW RW RW RW RW

Default 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Name PC Card 16-bit I/F legacy-mode base address

Type RW RW RW RW RW RW RW RW RW RW RW RW RW RW RW R

Default 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

Offset: 44h (functions 0, 1)

Type: Read-only, Read/Write

Default: 0000 0001h