RG82845 S L5YQ Intel, RG82845 S L5YQ Datasheet - Page 61

• Manufacturer Part Number: RG82845 S L5YQ
• Manufacturer: Intel

Specifications of RG82845 S L5YQ

• Lead Free Status / RoHS Status: Not Compliant

Intel
Table 9. PAM Register Attributes
®
82845 MCH for SDR Datasheet
R
For details on overall system address mapping scheme see Chapter 4.
DOS Application Area (00000h–9FFFh)
The DOS area is 640 KB in size and it is further divided into two parts. The 512 KB area at
0h to 7FFFFh is always mapped to the system memory controlled by the MCH, while the 128 KB
address range from 080000 to 09FFFFh can be mapped to PCI0 or to system memory. By default
this range is mapped to system memory and can be declared as a system memory hole (accesses
forwarded to PCI0) via MCH FDHC configuration register.
Video Buffer Area (A0000h–BFFFFh)
Attribute bits do not control this 128 KB area. The host -initiated cycles in this region are always
forwarded to either PCI0 or AGP unless this range is accessed in SMM mode. Routing of
accesses is controlled by the Legacy VGA control mechanism of the “virtual” PCI-PCI
bridge device embedded within the MCH.
This area can be programmed as SMM area via the SMRAM register. When used as a SMM
space, this range cannot be accessed from the hub interface or AGP.
Expansion Area (C0000h–DFFFFh)
This 128 KB area is divided into eight 16 KB segments, which can be assigned with different
attributes via PAM control register as defined by the table above.
PAM0[3:0]
PAM0[7:4]
PAM1[3:0]
PAM1[7:4]
PAM2[3:0]
PAM2[7:4]
PAM3[3:0]
PAM3[7:4]
PAM4[3:0]
PAM4[7:4]
PAM5[3:0]
PAM5[7:4]
PAM6[3:0]
PAM6[7:4]
PAM Reg
R
R
R
R
R
R
R
R
R
R
R
R
R
Attribute Bits
R
R
R
R
R
R
R
R
R
R
R
R
R
Reserved
WE
WE
WE
WE
WE
WE
WE
WE
WE
WE
WE
WE
RE
RE
RE
RE
RE
RE
RE
RE
RE
RE
RE
RE
RE
0F0000h–0FFFFFh
0C0000h–0C3FFFh
0C4000h–0C7FFFh
0C8000h–0CBFFFh
0CC000h–0CFFFFh
0D0000h–0D3FFFh
0D4000h–0D7FFFh
0D8000h–0DBFFFh
0DC000h–0DFFFFh
0E0000h–0E3FFFh
0E4000h–0E7FFFh
0E8000h–0EBFFFh
0EC000h–0EFFFFh
Memory Segment
BIOS Area
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
ISA Add-on BIOS
BIOS Extension
BIOS Extension
BIOS Extension
BIOS Extension
Comments
Register Description
Offset
90h
90h
91h
91h
92h
92h
93h
93h
94h
94h
95h
95h
96h
96h
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