Technical Reference Guide
Compaq Deskpro EXS and Workstation 300 Personal Computers
Featuring the Intel Pentium 4 Processor
First Edition - December 2000
4-35
4.8
REGISTER MAP AND MISCELLANEOUS FUNCTIONS
This section contains the system I/O map and information on general-purpose functions of the ICH
and I/O controller.
4.8.1 SYSTEM I/O MAP
Table 4-14 lists the fixed addresses of the input/output (I/O) ports.
Table 4-14.
System I/O Map
Table 4-14.
System I/O Map
I/O Port
Function
0000..001Fh
DMA Controller 1
0020..002Dh
Interrupt Controller 1
002E, 002Fh
Index, Data Ports to LPC47B357 I/O Controller (primary)
0030..003Dh
Interrupt Controller
0040..0042h
Timer 1
004E, 004Fh
Index, Data Ports to LPC47B357 I/O Controller (secondary)
0050..0052h
Timer / Counter
0060..0067h
Microcontroller, NMI Controller (alternating addresses)
0070..0077h
RTC Controller
0080..0091h
DMA Controller
0092h
Port A, Fast A20/Reset Generator
0093..009Fh
DMA Controller
00A0..00B1h
Interrupt Controller 2
00B2h, 00B3h
APM Control/Status Ports
00B4..00BDh
Interrupt Controller
00C0..00DFh
DMA Controller 2
00F0h
Coprocessor error register
0170..0177h
IDE Controller 2 (active only if standard I/O space is enabled for primary drive)
01F0..01F7h
IDE Controller 1 (active only if standard I/O space is enabled for secondary drive)
0278..027Fh
Parallel Port (LPT2)
02E8..02EFh
Serial Port (COM4)
02F8..02FFh
Serial Port (COM2)
0370..0377h
Diskette Drive Controller Secondary Address
0376h
IDE Controller 2 (active only if standard I/O space is enabled for primary drive)
0378..037Fh
Parallel Port (LPT1)
03B0..03DFh
Graphics Controller
03BC..03BEh
Parallel Port (LPT3)
03E8..03EFh
Serial Port (COM3)
03F0..03F5h
Diskette Drive Controller Primary Addresses
03F6h
IDE Controller 1 (active only if standard I/O space is enabled for sec. drive)
03F8..03FFh
Serial Port (COM1)
04D0, 04D1h
Interrupt Controller
0678..067Fh
Parallel Port (LPT2)
0778..077Fh
Parallel Port (LPT1)
07BC..07BEh
Parallel Port (LPT3)
0CF8h
PCI Configuration Address (dword access only )
0CF9h
Reset Control Register
0CFCh
PCI Configuration Data (byte, word, or dword access)
NOTE:
Assume unmarked gaps are unused, reserved, or used by functions that employ variable I/O
address mapping. Some ranges may include reserved addresses.