Ich Fixed I/O Registers - Compaq Deskpro EX User Manual

6.1.4

ICH Fixed I/O Registers

Port
00h, 02h, 04h, 06h
C0h, C4h, C8h, CCh
01h, 03h, 05h, 07h
C2h, C6h, Cah, CEh
10h-1Fh
20h
21h
24h-25h, 28-29h,
2Ch-2Dh, 30h-31h,
34h-35h, 38h-39h,
3Ch-3Dh
40h
41h
42h
43h
50h-53h
61h
70h
71h
72h
73h
74h-75h
76h-77h
81h, 82h, 83h
84h-86h, 88h
89h, 8Ah, 8Bh
8CH-8Eh
8Fh
91h-9Fh
(except 92h)
92h
CF9h
Register Name
Channel 0, 1, 2, 3 DMA Base & Current Address Regsiter
Channel 4, 5, 6, 7 DMA Base & Current Address Register
Channel 0, 1, 2, 3 DMA Base & Current Count Register
Channel 4, 5, 6, 7 DMA Base & Current Count Register
Aliased at 00h-0Fh
Master PIC ICW1 Init. Cmd Word 1 Register
Master PIC OCW2 Op Ctrl Word 2 Register
Master PIC OCW3 Op Ctrl Word 3 Register
Master PIC ICW2 Init. Cmd Word 1 Register
Master PIC ICW3 Init. Cmd Word 1 Register
Master PIC ICW4 Init. Cmd Word 1 Register
Master PIC OCW1 Op Ctrl Word 3 Register
Aliased at 20h-21h
Counter 0 Interval Time Status Byte Format
Counter 0 Counter Access Port Register
Counter 1 Interval Time Status Byte Format
Counter 1 Counter Access Port Register
Counter 2 Interval Time Status Byte Format
Counter 2 Counter Access Port Register
Timer Control Word Register
Timer Control Word Register Read Back
Counter Latch Command
Aliased at 40h-43h
NMI Status and Control Register
NMI Enable Register
Real-Time Clock (Standard RAM) Index Register
Real-Time Clock (Standard RAM) Target Register
Extended RAM Index Register
Extended RAM Target Register
Aliased at 70h-71h
Aliased at 72h-73h or 70h-71h
Channel 2, 3, 1 DMA Memory Low Page Register
Reserved Page Registers
Channel 6, 7, 5 DMA Memory Low Page Register
Reserved Page Registers
Refresh Low Page Register
Aliased at 81h-8Fh
Fast A20 and INIT Register
Reset Control Register
Compaq Deskpro EX Series of Personal Computers 6-3
continued