4.27 Subsystem ID Register

The subsystem ID register, used for system and option card identification purposes, 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). When bit 5 is 0, this register is read/write; when bit 5 is 1, this register is read-only. The default mode is read-only. All bits in this register are reset by GRST only.

If an EEPROM is present, then the subsystem ID and subsystem vendor ID is loaded from the EEPROM after a reset.

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

 

Register:

Subsystem ID

 

 

 

 

 

 

 

 

 

 

 

 

Offset:

 

42h (Functions 0, 1)

 

 

 

 

 

 

 

 

 

 

 

 

Type:

 

Read-only, (Read/Write when bit 5 in the system control register is 0)

 

 

 

 

Default:

 

0000h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

The PCI7x21/PCI7x11 controller supports the index/data scheme of accessing the ExCA registers, which is 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 specification, this register is shared by functions 0 and 1. See the ExCA register set description in Section 5 for register offsets. All bits in this register are reset by GRST only.

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

 

Register:

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

 

 

 

 

 

 

 

Offset:

 

44h (Functions 0, 1)

 

 

 

 

 

 

 

 

 

 

 

Type:

 

Read-only, Read/Write

 

 

 

 

 

 

 

 

 

 

 

Default:

0000 0001h

 

 

 

 

 

 

 

 

 

 

 

 

4−17

Page 107
Image 107
Texas Instruments PCI7421, PCI7411, PCI7611 Subsystem ID Register, PC Card 16-Bit I/F Legacy-Mode Base-Address Register