82374EB Datasheet, PDF (38/208 Pages) Intel Corporation – SYSTEM COMPONENT (ESC)

82374EB 82374SB
3 1 4 BIOSCSA BIOS CHIP SELECT A REGISTER
Address Offset
Default Value
Attribute
Size
42h
10h
Read Write
8 Bits
The LBIOSCS signal is used to decode access to the motherboard BIOS The ESC decodes memory access
to the following address ranges and if the range has been enabled the LBIOSCS signal is always asserted
for memory reads in the enabled BIOS range If the BIOS Write Enable bit is set in the configuration register
BIOSCSB the LBIOSCS is also asserted for memory write cycles
Bit
Description
7 6 Reserved
5 Enlarged BIOS During Memory access to locations FFF80000h – FFFDFFFFh with this bit set
LBIOSCS will be asserted for memory read cycles If bit 3 of BIOSCSB is set then LBIOSCS will
be asserted for write cycles as well
4 High BIOS During Memory access to locations 0F0000h – 0FFFFFh FF0000h – FFFFFFh
FFFF0000h–FFFFFFFFh with this bit set LBIOSCS will be asserted for memory read cycles If bit 3
of BIOSCSB is set then LBIOSCS will be asserted for write cycles as well
3 Low BIOS 4 During Memory access to locations 0EC000h – 0EFFFFh FFEEC000h – FFEEFFFFh
FFFEC000h–FFFEFFFFh with this bit set LBIOSCS will be asserted for memory read cycles If bit 3
of BIOSCSB is set then LBIOSCS will be asserted for write cycles as well
2 Low BIOS 3 During Memory access to locations 0E8000h – 0EBFFFh FFEE8000h – FFEEBFFFh
FFFE8000h–FFFEBFFFh with this bit set LBIOSCS will be asserted for memory read cycles If bit 3
of BIOSCSB is set then LBIOSCS will be asserted for write cycles as well
1 Low BIOS 2 During Memory access to locations 0E4000h – 0E7FFFh FFEE4000h – FFEE7FFFh
FFFE4000h–FFFE7FFFh with this bit set LBIOSCS will be asserted for memory read cycles If bit 3
of BIOSCSB is set then LBIOSCS will be asserted for write cycles as well
0 Low BIOS 1 During Memory access to locations 0E0000h – 0E3FFFh FFEE0000h – FFEE3FFFh
FFFE0000h–FFFE3FFFh with this bit set LBIOSCS will be asserted for memory read cycles If bit 3
of BIOSCSB is set then LBIOSCS will be asserted for write cycles as well
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