Register Description
R
3.5.26AGPSTAT—AGP  Status Register (Device 0)
Address Offset:  | |
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 |