82830MP Datasheet, PDF (61/159 Pages) Intel Corporation – Intel 830MP Chipset: 82830MP Graphics and Memory Controller Hub (GMCH-M)

Intel^® 830MP Chipset
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Table 21. PAM Registers and Associated Memory Segments
PAM Reg
Attribute Bits
Memory Segment
Comments
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]
Reserved
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE RE
R R WE 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
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
Offset
59h
59h
5Ah
5Ah
5Bh
5Bh
5Ch
5Ch
5Dh
5Dh
5Eh
5Eh
5Fh
5Fh
For details on overall system address mapping scheme see the Address Decoding Section of this
document.
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 0 to 7FFFFh
is always mapped to the main memory controlled by the GMCH-M, while the 128-KB address range
from 080000 to 09FFFFh can be mapped to PCI0 or to main SDRAM. By default this range is mapped
to main memory and can be declared as a main memory hole (accesses forwarded to PCI0) via GMCH-
M’s FDHC configuration register.
Video Buffer Area (A0000h-BFFFFh)
This 128-KB area is not controlled by attribute bits. The host -initiated cycles in this region are always
forwarded to either PCI0 or AGP/PCI1 or PCI2 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 GMCH-M.
This area can be programmed as SMM area via the SMRAM register. When used as an SMM space this
range cannot be accessed from Hub Interface or AGP.
Expansion Area (C0000h-DFFFFh)
This 128-KB area is divided into eight 16-KB segments that can be assigned with different attributes via
PAM control register as defined by Table 21.
Extended System BIOS Area (E0000h-EFFFFh)
This 64-KB area is divided into four 16-KB segments that can be assigned with different attributes via
PAM control register as defined by the Table 21.
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Datasheet
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