AXIOMTEK PICO50R, User Manual

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PICO50R/51R Pico-ITX Board
Digital I/O 63
Appendix B
Digital I/O
B.1 About Digital I/O
The onboard GPIO or digital I/O has 4 bits (DIO1~4). 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 2 inputs and 2 outputs.
CN14
B.2 Digital I/O Programming
Assembly sample code :
mov
dx,fa31 ; Set DIO 0-3 to Output
mov al,00
out dx,al
mov
dx,fa32 ; Set DIO 2-3 to High
mov al,0c
out dx,al
mov
dx,fa31 ; Set DIO 0-3 to Input
mov al,0f
out dx,al
mov
dx,fa32 ; Get DIO 0-3 status
in al,dx
mov
dx,fa31 ; Set DIO 0-1 to Input, 2-3 to Output
mov al,03 ; al = 03 => 00000011
out dx,al
mov
dx,fa32 ; Set DIO 3 to High
mov al,08 ; al = 08 => 00001000
out dx,al
in
al,dx ; Get DIO 0-2 status
Pin Signal Pin Signal
1 DIO 0 2 DIO 3
3 DIO 1 4 DIO 2
5 +5V 6 GND
SW1
CN1
JP1
CN3
CN4
CN8
CN9
CN6
BAT1
CN14
CN13
CN12
CN11 CN10
CN7
CN5
CN2