82801FB Datasheet, PDF (354/786 Pages) Intel Corporation – Intel I/O Controller Hub 6 (ICH6) Family

LPC Interface Bridge Registers (D31:F0)
10.1.19
LPC_I/O_DEC—I/O Decode Ranges Register
(LPC I/F—D31:F0)
Offset Address: 80h
Default Value: 0000h
Attribute:
Size:
R/W
16 bit
Bit
Description
15:13
12
11:10
9:8
7
6:4
3
2:0
Reserved
FDD Decode Range — R/W. This bit determines which range to decode for the FDD Port
0 = 3F0h – 3F5h, 3F7h (Primary)
1 = 370h – 375h, 377h (Secondary)
Reserved
LPT Decode Range — R/W. This field determines which range to decode for the LPT Port.
00 = 378h – 37Fh and 778h – 77Fh
01 = 278h – 27Fh (port 279h is read only) and 678h – 67Fh
10 = 3BCh –3BEh and 7BCh – 7BEh
11 = Reserved
Reserved
COMB Decode Range — R/W. This field determines which range to decode for the COMB Port.
000 = 3F8h – 3FFh (COM1)
001 = 2F8h – 2FFh (COM2)
010 = 220h – 227h
011 = 228h – 22Fh
100 = 238h – 23Fh
101 = 2E8h – 2EFh (COM4)
110 = 338h – 33Fh
111 = 3E8h – 3EFh (COM3)
Reserved
COMA Decode Range — R/W. This field determines which range to decode for the COMA Port.
000 = 3F8h – 3FFh (COM1)
001 = 2F8h – 2FFh (COM2)
010 = 220h – 227h
011 = 228h – 22Fh
100 = 238h – 23Fh
101 = 2E8h – 2EFh (COM4)
110 = 338h – 33Fh
111 = 3E8h – 3EFh (COM3)
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Intel^® I/O Controller Hub 6 (ICH6) Family Datasheet