AXIOMTEK CAPA311, User Manual

Page: 75 / 76

CAPA311/312 3.5
” Board
Digital I/O 69
Appendix B
Digital I/O
B.1 About Digital I/O
The onboard GPIO or digital I/O has 8 bits (DIO1~8). Each bit can be set to function as input or
output by software programming. In default, all pins are pulled high with +5V level (according
to main power). The BIOS default settings are 4 inputs and 4 outputs.
CN6
B.2 Digital I/O Programming
Assembly sample code :
mov dx,fa18 ; Set DIO 0-7 to Output
mov al,00
out dx,al
mov
dx,fa19 ; Set DIO 4-7 to High
mov al,f0
out dx,al
mov
dx,fa18 ; Set DIO 0-7 to Input
mov al,ff
out dx,al
mov
dx,fa19 ; Get DIO 0-7 status
in al,dx
mov
dx,fa18 ; Set DIO 0-4 to Input, 5-7 to Output
mov al,1f ; al = 1F => 00011111
out dx,al
mov
dx,fa19 ; Set DIO 6 to High
mov al,40 ; al = 40 => 01000000
out dx,al
in
al,dx ; Get DIO 0-7 status
Pin Signal Pin Signal
1 DI1 2 DO8
3 DI2 4 DO7
5 DI3 6 DO6
7 DI4 8 DO5
9 +5V 10 GND