Graphics, Video, and Display (D2:F0)
9.4.16
GC—Graphics Control Register
Register Address:
Default Value:
52h–53h
0030h
Attribute:
Size:
RO, R/W
16 bits
Default
Bit
and
Description
Access
0
RO
15:7
Reserved
Graphics Mode Select (GMS): This field is used to select the amount of
memory pre-allocated to support the graphics device in VGA (non-linear)
and Native (linear) modes. If graphics is disabled, this value must be
programmed to 000h.
Bits 6:4
Description
No memory pre-allocated. Graphics does not claim
VGA cycles (Mem and I/O), and CC.SCC is 80h.
000
011b
R/W
001
010
1 MB of memory pre-allocated for frame buffer.
4 MB of memory pre-allocated for frame buffer.
8 MB of memory pre-allocated for frame buffer.
reserved
6:4
011
others
This register is locked and becomes Read Only when the D_LCK bit in the
SMRAM register is set. Hardware does not clear or set any of these bits
automatically based on the Intel Graphics Media Adapter being disabled/
enabled.
00b
RO
3:2
1
Reserved
VGA Disable (VD)
0
RO
0 = VGA memory and I/O cycles are enabled, and CC.SCC is set to 00h.
1 = VGA memory or I/O cycles are not claimed, and CC.SCC is set to 80h.
0
RO
0
Reserved
9.4.17
SSRW—Software Scratch Read/Write Register
Register Address:
Default Value:
58h–5Bh
00000000h
Attribute:
Size:
R/W
32 bits
Default
Bit
and
Description
Access
0
R/W
31:0
Scratch (S): Scratchpad bits
110
Datasheet
INTEL [ INTEL ]
