12.15 Maximum Latency Register

The maximum latency register contains the maximum latency value for the SD host controller core.

 

Bit

 

7

 

6

5

4

3

2

1

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Name

 

 

 

 

 

 

Maximum latency

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Type

 

RU

 

RU

 

RU

RU

RU

RU

RU

 

RU

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Default

 

0

 

0

0

0

0

1

0

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Register:

Maximum latency

 

 

 

 

 

 

 

 

Offset:

3Fh

 

 

 

 

 

 

 

 

 

 

 

Type:

Read/Update

 

 

 

 

 

 

 

 

Default:

04h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 12−10. Maximum Latency Register Description

 

 

 

 

 

 

 

 

 

 

 

 

BIT

FIELD NAME

TYPE

 

 

 

 

 

 

DESCRIPTION

 

 

 

 

 

 

 

7−0

MAX_LAT

RU

 

Maximum latency. The contents of this field may be used by host BIOS to assign an arbitration priority level

 

 

 

 

 

 

 

to the SD host controller. The default for this register indicates that the SD host controller may need to

 

 

 

 

 

 

 

access the PCI bus as often as every 0.25 s; thus, an extremely high priority level is requested. The

 

 

 

 

 

 

 

contents of this field may also be loaded through the serial EEPROM.

12.16 Slot Information Register

This read-only register contains information on the number of SD sockets implemented and the base address Registers used.

Bit

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Name

 

 

 

Slot information

 

 

 

 

 

 

 

 

 

 

 

 

Type

R

R

R

R

R

R

R

R

 

 

 

 

 

 

 

 

 

Default

0

X

X

X

0

0

0

0

 

 

 

 

 

 

 

 

 

Register: Maximum latency

Offset: 40h

Type: Read/Update

Default: X0h

Table 12−11. Maximum Latency Register Description

BIT

FIELD NAME

TYPE

DESCRIPTION

 

 

 

 

7

RSVD

R

Reserved. This bit returns 0 when read.

 

 

 

 

6−4

NUMBER_SLOTS

R

Number of slots. This field indicates the number of SD sockets supported by the SD host controller.

 

 

 

Since the controller supports three SD sockets, this field returns 010 when read.

 

 

 

 

3

RSVD

R

Reserved. This bit returns 0 when read.

 

 

 

 

2−0

FIRST_BAR

R

First base address register number. This field is hardwired to 000b to indicate that the first BAR used

 

 

 

for the SD host standard registers is BAR0.

 

 

 

 

12−10

Page 264
Image 264
Texas Instruments PCI7411 Slot Information Register, Register Maximum latency, 11. Maximum Latency Register Description