Intel® 82854 Graphics Memory Controller Hub (GMCH)

4.8.15DAFC – Device and Function Control Register (Device #0)

Address Offset:

54-55h

Default Value:

0000h

Access:

Read/Write

Size:

16 bits

This 16-bit register controls the visibility of devices and functions within the GMCH to configuration software.

Bit

Description

 

 

15:8

Reserved

 

 

7

Device #2 Disable:

 

1: Disabled.

 

0: Enabled.

 

 

6:3

Reserved

 

 

2

Device #0 Function #3 Disable:

 

1: Disable Function #3 registers within Device #0 and all associated DDR SDRAM and I/O ranges.

 

0: Enable Function #3 within Device #0.

 

 

1

Reserved

 

 

0

Device #0 Function #1 Disable:

 

1: Disable Function #1 within Device #0.

 

0: Enable Function #1 within Device #0.

 

 

4.8.16FDHC – Fixed DRAM Hold Control Register (Device #0)

Address Offset:

58h

Default Value:

00h

Access:

Read/Write

Size:

8 bits

This 8-bit register controls a single fixed DDR SDRAM hole: 15-16 MB.

Bit

Description

7Hole Enable (HEN): This field enables a memory hole in DDR SDRAM space. Host cycles matching an enabled hole are passed onto ICH4-M through Hub interface. The GMCH will ignore Hub interface cycles matching an enabled hole.

NOTE: A selected hole is not re-mapped.

0:None

1:15 MB–16 MB (1MBs)

6:0

Reserved

60

D15343-003

Page 60
Image 60
Intel D15343-003 Dafc Device and Function Control Register Device #0, Fdhc Fixed Dram Hold Control Register Device #0