System Address Map
Figure 3-1 represents system memory address map in a simplified form.
Figure 3-1. System Address Ranges
Host/System
View
Physical Memory
(DRAM Controller
View)
64 GB
PCI Memory
Address
Range
(subtractively
decoded to
DMI
Device
1
Bars
Device
0
Bars
Device
3
TOM
64 MB Aligned
Reclaim Limit =
Reclaim Base +X
(64 MB Aligned)
Independently Programmable
Non-Overlapping Windows
EP-UMA
(1 – 64 MB)
Main Memory
Reclaim
Address
TOUUD Base
EP Stolen Base
1 MB Aligned
64 MB Aligned
0 – 63 MB
Unusable
Range
Reclaim Base
(64 MB Aligned)
Main Memory
Address
Range
OS Visible
> 4 GB
4 GB
X
PCI Memory
Address
Range
(subtractively
decoded to
DMI)
OS Invisible
Reclaim
Device 0
GGC (GFX
Stolen
TOLUD
Device
Base
Device
1
Bars
Device
3
64 MB Aligned for
Reclaim
Device
2
M HBA
0
(64 MB
Bars
GFX Stolen
(1 – 64 MB)
Mem)
Aligned)
1 MB Aligned
1 MB Aligned
TSEG
(0 – 8 MB)
Independently Programmable
Non-Overlapping Windows
TSEG
Main Memory
Address
Range
OS Visible
< 4 GB
1 MB
Legacy
Address
Range
0
Memap_Sys_Addr_Ranges
3.1
Legacy Address Range
This area is divided into the following address regions:
• 0 - 640 KB – DOS Area
• 640 - 768 KB – Legacy Video Buffer Area
• 768 - 896 KB in 16KB sections (total of 8 sections) – Expansion Area
• 896 - 960 KB in 16KB sections (total of 4 sections) – Extended System BIOS Area
• 960 KB - 1 MB Memory – System BIOS Area
46
Datasheet
INTEL [ INTEL ]
