82443LX Datasheet, PDF (47/144 Pages) Intel Corporation – INTEL 440LX AGPSET: 82443LX PCI A.G.P. CONTROLLER (PAC)

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Table 11 shows the PAM registers and the associated attribute bits:
INTEL 82443LX (PAC)
Table 11. PAM Registers and Associated Memory Segments
PAM Reg.
Attribute Bits
Memory Segment
Comments
Offset
PAM0[3:0]
Reserved
59h
PAM0[7:4] R R WE RE 0F0000h–0FFFFFh
BIOS Area
59h
PAM1[3:0] R R WE RE 0C0000h–0C3FFFh
ISA Add-on BIOS¹ 5Ah
PAM1[7:4] R R WE RE 0C4000h–0C7FFFh
ISA Add-on BIOS¹ 5Ah
PAM2[3:0] R R WE RE 0C8000h–0CBFFFh
ISA Add-on BIOS¹ 5Bh
PAM2[7:4] R R WE RE 0CC000h–0CFFFFh
ISA Add-on BIOS¹ 5Bh
PAM3[3:0] R R WE RE 0D0000h–0D3FFFh
ISA Add-on BIOS
5Ch
PAM3[7:4] R R WE RE 0D4000h–0D7FFFh
ISA Add-on BIOS
5Ch
PAM4[3:0] R R WE RE 0D8000h–0DBFFFh
ISA Add-on BIOS
5Dh
PAM4[7:4] R R WE RE 0DC000h–0DFFFFh
ISA Add-on BIOS
5Dh
PAM5[3:0] R R WE RE 0E0000h–0E3FFFh
BIOS Extension
5Eh
PAM5[7:4] R R WE RE 0E4000h–0E7FFFh
BIOS Extension
5Eh
PAM6[3:0] R R WE RE 0E8000h–0EBFFFh
BIOS Extension
5Fh
PAM6[7:4] R R WE RE 0EC000h–0EFFFFh
BIOS Extension
5Fh
NOTES:
1. The C0000h to CFFFFh segment can be used for SMM space if enabled by the SMRAM register.
DOS Application Area (00000h–9FFFFh)
The DOS area is 640 KB in size and is further divided into two parts. The 512-KB area at 0 to 7FFFFh is
always mapped to the main memory controlled by PAC, while the 128-KB address range from 080000 to
09FFFFh can be mapped to PCI or to main DRAM. By default this range is mapped to main memory and can
be declared as a main memory hole (accesses forwarded to PCI) via PAC’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 PCI or A.G.P. bus for termination. Routing of accesses is controlled by AGPCTRL register
(Device 1). This area can be programmed as SMM area via the SMRAM register. When used as a SMM
space this range can not be accessed from PCI or A.G.P.
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