Intel D425 AU80610006252AA User Manual

122  

Datasheet  

B/D/F/Type: 0/2/0/PCI 

Address Offset: 

60-61h 

Default Value: 

0000h 

Access:  

RW; 

Size: 16 

bits 

 

 

15:0 RW  0000h 

Reserved R/W ():  
 

B/D/F/Type: 0/2/0/PCI 

Address Offset: 

62h 

Default Value: 

01h 

Access: 

 RW; RO; RW/K; 

Size: 8 

bits 

This register determines the size of the graphics memory aperture in function 0 and in 
the trusted space. Only the system BIOS will write this register based on pre- boot 

address allocation efforts, but the graphics may read this register to determine the 
correct aperture size. System BIOS needs to save this value on boot so that it can 

reset it correctly during S3 resume. 

 

 

7:4 RW  0h 

Reserved R/W ():  
 Scratch Bits Only --  Have no physical effect 
on hardware 

3:2 RO  00b 

1:0 RW/K  01b 

Untrusted Aperture Size (LHSAS):  
00:

 

Reserved 

01:

 

512MB.  Bit 28 and 27 of GMADR are 

read-only, allowing 512 MB of address space to 
be mapped. 
10:

 

256MB.  Bit 28 of GMADR is read-write 

and bit 27 of GMADR is read-only, limiting the 
address space to 256MB. 
11:

 

128MB.  Bits 28 and 27 of GMADR are 

read-write, allowing 128 MB of address space 
to be mapped.