AXIOMTEK CAPA831, Руководство пользователя

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CAPA831 Intel
®
Atom
TM
D2550/N2800/N2600 Processor 3.5” SBC
68
Digital I/O
;Programming DIO as in/out.
mov dx,2Eh
mov al,0E0h
out dx,al
mov dx,2Fh
mov al,Nh
;If N=07h, DIO is programmed as 3 inputs
out dx,al ;and 5 outputs (see below
Note1)
Digital Input:
;Read digital input data.
mov dx,2Eh
mov al,0E1h
out dx,al
mov dx,2Fh ;If N=07h, bit0~2 represent DIO0~2,
in dx, al ;bit0~2 are DIO pin 0~2 state (1 High, 0 Low)
;(see below
Note2)
Digital Output:
; Set DIO digital output pins value.
mov dx,2Eh
mov al,0E1h
out dx,al
mov dx,2Fh
mov al,M ;If N=07h, bit3~7 represent DIO3~7,
out dx,al ;set output value M
;bit3~7 are DIO pin 3~7 state (1 High, 0 Low)
;if M=FFh, all DIO pins are high
;(see below
Note3)
Note1:
The N has 8 bits. Every bit’s value is either 1 or 0.
" 1" means that the bit is programmed to input.
" 0" means that the bit is programmed to output.
Ex:
1. N=00h=00000000b
DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
Output Output Output Output Output Output Output Output
2. N=02h=00000010b
DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
Output Output Output Output Output Output Input Output
3. N=07h=00000111b
DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
Output Output Output Output Output Input Input Input
4. N=F2h=11110010b
DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
Input Input Input Input
Output Output
Input
Output
Note2:
If N=07h
DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
Output Output Output Output Output Input Input Input