4.9 Latency Timer Register

The latency timer register specifies the latency timer for the PCI7x21/PCI7x11 controller, in units of PCI clock cycles. When the PCI7x21/PCI7x11 controller is a PCI bus initiator and asserts FRAME, the latency timer begins counting from zero. If the latency timer expires before the PCI7x21/PCI7x11 transaction has terminated, then the PCI7x21/PCI7x11 controller terminates the transaction when its GNT is deasserted.

Bit

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Name

 

 

 

Latency timer

 

 

 

 

 

 

 

 

 

 

 

 

Type

RW

RW

RW

RW

RW

RW

RW

RW

 

 

 

 

 

 

 

 

 

Default

0

0

0

0

0

0

0

0

Register: Latency timer

Offset: 0Dh

Type: Read/Write

Default: 00h

4.10 Header Type Register

The header type register returns 82h when read, indicating that the PCI7x21/PCI7x11 functions 0 and 1 configuration spaces adhere to the CardBus bridge PCI header. The CardBus bridge PCI header ranges from PCI registers 00h−7Fh, and 80h−FFh is user-definable extension registers.

Bit

7

6

 

5

4

 

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

Name

 

 

 

 

 

Header type

 

 

 

 

 

 

 

 

 

 

 

 

 

Type

R

R

 

R

R

 

R

R

R

R

 

 

 

 

 

 

 

 

 

 

 

Default

1

0

 

0

0

 

0

0

1

0

 

Register:

Header type

 

 

 

 

 

 

 

 

Offset:

0Eh (Functions 0, 1)

 

 

 

 

 

 

 

Type:

Read-only

 

 

 

 

 

 

 

 

Default:

82h

 

 

 

 

 

 

 

4.11 BIST Register

Because the PCI7x21/PCI7x11 controller does not support a built-in self-test (BIST), this register returns the value of 00h when read.

Bit

7

6

5

4

 

3

2

1

0

 

 

 

 

 

 

 

 

 

 

Name

 

 

 

 

BIST

 

 

 

 

 

 

 

 

 

 

 

 

 

Type

R

R

R

R

 

R

R

R

R

 

 

 

 

 

 

 

 

 

 

Default

0

0

0

0

 

0

0

0

0

 

Register:

BIST

 

 

 

 

 

 

 

 

Offset:

0Fh (Functions 0, 1)

 

 

 

 

 

 

 

Type:

Read-only

 

 

 

 

 

 

 

 

Default:

00h

 

 

 

 

 

 

 

4−7

Page 97
Image 97
Texas Instruments PCI7611 Latency Timer Register, Header Type Register, Bist Register, Register Latency timer, Header type