Intel G550T CM8062301002309 User Manual

Product codes
CM8062301002309
Page of 296
Processor Configuration Registers
42
Datasheet, Volume 2
Accesses to the VGA memory range are directed to IGD depend on the configuration. 
The configuration is specified by: 
• Internal Graphics Controller in Device 2 is enabled (DEVEN.D2EN bit 4)
• Internal Graphics VGA in Device 0, function 0 is enabled through register GGC bit 1.
• IGD memory accesses (PCICMD2 04 – 05h, MAE bit 1) in Device 2 configuration 
space are enabled.
• VGA Compatibility Memory accesses (VGA Miscellaneous output Register - MSR 
Register, bit 1) are enabled.
• Software sets the proper value for VGA Memory Map Mode Register (VGA GR06 
Register, bits 3-2). See 
 for translations. 
Note:
Additional qualification within IGD comprehends internal MDA support. The VGA and 
MDA enabling bits detailed below control segments not mapped to IGD.
VGA I/O range is defined as addresses where A[15:0] are in the ranges 03B0h to 
03BBh, and 03C0h to 03DFh. VGA I/O accesses are directed to IGD depends on the 
following configuration. 
• Internal Graphics Controller in Device 2 is enabled through register DEVEN.D2EN 
bit 4.
• Internal Graphics VGA in Device 0 function 0 is enabled through register GGC bit 1.
• IGD I/O accesses (PCICMD2 04 – 05h, IOAE bit 0) in Device 2 are enabled.
• VGA I/O decodes for IGD uses 16 address bits (15:0) there is no aliasing. Note that 
this is different when compared to a bridge device (Device 1) that used only 10 
address bits (A 9:0) for VGA I/O decode. 
• VGA I/O input/output address select (VGA Miscellaneous output Register – MSR 
Register, bit 0) used to select mapping of I/O access as defined in 
.
Note:
Additional qualification within IGD comprehends internal MDA support. The VGA and 
MDA enabling bits detailed below control ranges not mapped to IGD.
Table 2-4.
IGD Frame Buffer Accesses
Mem Access
GR06(3:2)
A0000h–AFFFFh
B0000h–B7FFFh
MDA
B8000h–BFFFFh
00
IGD
IGD
IGD
01
IGD
PCI Express Bridge or DMI 
Interface
PCI Express Bridge or DMI 
Interface
10
PCI Express Bridge or 
DMI Interface
IGD
PCI Express Bridge or DMI 
Interface
11
PCI Express Bridge or 
DMI Interface
PCI Express Bridge or DMI 
Interface
IGD
Table 2-5.
IGD VGA I/O Mapping
I/O Access 
MSRb0
3CX
3DX
3B0–3BB
3BC–3BF
0
IGD
PCI Express Bridge or DMI 
Interface
IGD
PCI Express Bridge or 
DMI Interface
1
IGD
IGD
PCI Express Bridge or 
DMI Interface
PCI Express Bridge or 
DMI Interface