Appendix, A. i/o port address map, B. interrupt request lines (irq) – IBASE MB838 User Manual
Page 48

APPENDIX
MB838 User’s Manual
48
Appendix
A. I/O Port Address Map
Each peripheral device in the system is assigned a set of I/O port
addresses which also becomes the identity of the device. The following
table lists the I/O port addresses used.
Address
Device Description
000h - 01Fh
DMA Controller #1
020h - 03Fh
Interrupt Controller #1
040h - 05Fh
System Timer
060h - 064h
Keyboard Controller
070h - 07Fh
Real Time Clock
080h - 09Fh
DMA Controller #2
0A0h - 0BFh
Interrupt Controller #2
0C0h - 0DFh
DMA Controller #3
0F0h
Clear Math Coprocessor Busy Signal
0F1h
Reset Math Coprocessor
3B0h- 3DFh
Graphics adapter Controller
3F8h - 3FFh
Serial Port #0 (COM1)
2F8h - 2FFh
Serial Port #1 (COM2)
3E8h – 3EFh
Serial Port #2 (COM3)
2E8h – 2EFh
Serial Port #3 (COM4)
3E8h - 3EFh
Serial Port #4 (COM5)
2E8h - 2EFh
Serial Port #5 (COM6)
360h - 36Fh
Network Ports
B. Interrupt Request Lines (IRQ)
Peripheral devices use interrupt request lines to notify CPU for the
service required. The following table shows the IRQ used by the devices
on board.
Level
Function
IRQ0
System Timer Output
IRQ1
Keyboard
IRQ4
Serial Port #1
IRQ3
Serial Port #2
IRQ5
Serial Port #3
IRQ11
Serial Port #4
IRQ8
Real Time Clock
IRQ14
Primary IDE
IRQ15
Secondary IDE