101019
OPERATIONS MANUAL PPM-LX800-G
39
Following is a list of PC I/O ports. I/O addresses marked with ‘**’ are generally unused and
should be the basis for the first choices in I/O address selection for external I/O boards.
NOTE:
The PPM-LX800-G uses a PnP BIOS resource allocation. Care must be taken to avoid
contention with resources allocated by the BIOS.
Hex Range
Usage
000-00F
8237DMA Controller #1
**
010-01F
Free
020-021
8259 PIC #1
**
022-03F
Free
040-043
8254 PIT
**
044-04D
Free
04E-04F
Reserved for on-board configuration
**
050-05F
Free
060-06F
8042 Keyboard / Mouse Controller
070-07F
CMOS RAM, Clock / Calendar
080-09F
DMA Page Registers
0A0-0BF
8259 PIC #2
0C0-0DF
8237 DMA Controller #2
**
0E0-0EF
Free
0F0-0F1
Math Co-processor Control
**
0F2-0F7
Free
0F8-0FF
Math Co-processor
100-102
Video Controllers
**
103-11F
Free
120-12F
Digital I/O
**
130-14F
Free
150
Reserved for on-board configuration
**
151-1CF
Free
1D0-1DF
Legacy Watchdog (1D0-Enabled; 1D8 - Pet)
1E8-1EB
Reserved for on-board configuration
1EC
Interrupt Status Register
1ED
Status LED
1EE-1EF
Watchdog Timer Control
1F0-1FF
IDE Controller #1
**
200-277
Free
**
278-27F
Free (Option for LPT)
**
280-2A7
Free
**
2A8-2AF
Free (Option for on-board serial ports)
2B0-2DF
Video Controllers
**
2E0-2E7
Free
2E8-2EF
COM4 – (Default)
**
2F0-2F7
Free
2F8-2FF
COM2 – (Default)
**
300-377
Free
378-37B
LPT (Default)
**
37C- 3A7 Free
**
3A8- 3AF Free (Option for on-board serial ports)
3B0-3BB
Video Controllers
**
3BC-3BF
Free (Option for LPT)
3C0-3DF
Video Controllers
**
3E0-3E7
Free
3E8- 3EF
COM3 – (Default)
**
3F0-3F7
Free
3F8-3FF
COM1 – (Default)
564-568
Advanced Watchdog
I/O Port Map