Appendix B Digital I/O; B.1 About Digital I/O; B.2 Digital I/O Programming - AXIOMTEK CAPA312 User Manual

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.

B.2 Digital I/O Programming

Assembly sample code :
mov dx,fa18
mov al,00
out dx,al
mov dx,fa19
mov al,f0
out dx,al
mov dx,fa18
mov al,ff
out dx,al
mov dx,fa19
in al,dx
mov dx,fa18
mov al,1f
out dx,al
mov dx,fa19
mov al,40
out dx,al
in al,dx
Digital I/O
; Set DIO 0-7 to Output
; Set DIO 4-7 to High
; Set DIO 0-7 to Input
; Get DIO 0-7 status
; Set DIO 0-4 to Input, 5-7 to Output
; al = 1F => 00011111
; Set DIO 6 to High
; al = 40 => 01000000
; Get DIO 0-7 status
CAPA312 3.5" Board
Appendix B
Digital I/O
CN6
Pin Signal Pin
1 DI1 2
3 DI2 4
5 DI3 6
7 DI4 8
9 +5V 10
Signal
DO8
DO7
DO6
DO5
GND
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