IEI Technology PCISA-PV-D4251, User Manual

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PCISA-PV-D4251/N4551/D5251 CPU Card
Page 128
E.1 Introduction
The digital I/O is used for machine control and automation.
E.2 DIO Connector Pinouts
Located in the Connectors section of this document.
E.3 Assembly Language Example
;**************************************************
; DIO Port: 0A21h[3:0] (4 Out)
; 0A22h[3:0] (4 In)
;**************************************************
;==================================================
; Get current input and output values into AL register
; AL: bit0~bit3 as output value
; bit4~bit7 as Input value
;==================================================
mov dx,
0A21h ; GPIO output I/O base address
in al, dx ; Get output status
jmp $+2 ; Wait
jmp $+2 ; Wait
and al, 0Fh
mov bl, al ; Move al to bl temporarily
inc dx ; sets dx to 0A22h
in al, dx ; Get input status
jmp $+2 ; Wait
jmp $+2 ; Wait
and al, 0Fh
rol al, 4 ; Shift input values over
or al, bl ; Merge all results into AL
; AL: bit0~bit3 as output value
; bit4~bit7 as input value
;==================================================
; Output value (x) to GPIO
; AL: bit0~bit3 as output value
;==================================================
mov al, 0xh ; x is the output value (0 ~ Fh)
mov dx,
0A21h ; GPIO output I/O base address
out dx, al ; bit0 ~ bit3 as Output value
; bit4 ~ bit7 are Reserved