DIGITAL-LOGIC SM800/900DK, Technical User'S Manual

Page: 87 / 103

DIGITAL-LOGIC AG
SM800/900DK Technical Manual V1.2B
87
;CRF2 (GP30-GP35 inversion register. Bit 7-6: Reserve)
;When set to a '1', the incoming/outgoing port value is inverted.
;When set to a '0', the incoming/outgoing port value is the same as in data register.
MOV DX,2EH
MOV AL,0F2H
OUT DX,AL ; select CRF2
MOV DX,2FH
IN AL, DX
AND AL, ... ; user masks for separated IOs
OR AL, ... ; ----""----
OUT DX,AL ; update CRF2
;
;CRF1 (GP30-GP35 data register. Bit 7-6: Reserve)
;If a port is programmed to be an output port, then its respective bit can be read/written.
;If a port is programmed to be an input port, then its respective bit can only be read.
MOV DX,2EH
MOV AL,0F1H
OUT DX,AL ; select CRF1
MOV DX,2FH
IN AL, DX ; read data from GPIOs - into AL - just an example!!!
; MOV AL, ...
; OUT DX, AL ; write data to GPIOs
;------------------------------------------
; Exit extended function mode
;------------------------------------------
MOV DX,2EH
MOV AL,0AAH
OUT DX,AL
RET