Register Description

R

3.5.26AGPSTAT—AGP Status Register (Device 0)

Address Offset:

A4–A7h

Default Value:

1F00_0217h

Access:

RO

Size:

32 bits

This register reports AGP device capability/status.

Bit

Description

 

 

31:24

Request Queue (RQ). This field contains the maximum number of AGP command requests the

 

MCH is configured to manage.

 

1Fh = Allows a maximum of 32 outstanding AGP command requests.

 

 

23:10

Reserved.

 

 

9

Side Band Addressing Support (SBA). Hardwired to 1 to indicate that the MCH supports side

 

band addressing.

 

 

8:6

Reserved.

 

 

5

Greater that 4 GB Support (4G). Hardwired to 0 to indicate that the MCH does not support

 

addresses greater than 4.

 

 

4

Fast Write Support (FW). Hardwired to 1 to indicate that the MCH supports Fast Writes from the

 

host to the AGP master.

 

 

3

Reserved.

 

 

2:0

Data Rate Support (RATE). Hardwired to 111. After reset, the MCH reports its data transfer rate

 

capability. Bit 0 identifies if AGP device supports 1x data transfer mode, bit 1 identifies if AGP

 

device supports 2x data transfer mode, bit 2 identifies if AGP device supports 4x data transfer

 

mode.

 

111 = 1x, 2x, and 4x data transfer modes are supported by the MCH

 

Note: The selected data transfer mode applies to both AD bus and SBA bus. It also applies to

 

Fast Writes if they are enabled.

 

 

66

Intel® 82845 MCH for SDR Datasheet

Page 66
Image 66
Intel 845 manual AGPSTAT-AGP Status Register Device, This register reports AGP device capability/status