Specifications

Application Examples
LED PROCEDURE
; THE LED CAN BE TURNED ON AND OFF UNDER SOFTWARE CONTROL. THIS
; IS A VALUABLE STATUS INDICATOR, ESPECIALLY DURING THE DEBUG
; PHASE OF APPLICATION DEVELOPMENT. THE FOLLOWING CODE SHOWS
; THE PROCEDURE FOR ARMING THE LED AND TURNING IT ON AND OFF.
;
; INPUTS: NONE
; OUTPUTS: LED IS ARMED
; CALLS: NONE
; DESTROYS: FLAGS
LED_INIT PROC
; PRESERVE REGISTER STATUS
PUSH AX
PUSH DX
; ARM THE LED
PUT PAR_PORT_0,PAR_PORT_INIT
PUT PAR_PORT_1,PAR_PORT_INIT
PUT PAR_PORT_2,PAR_PORT_INIT
MOV DX,ACC_MODC
IN AL,DX
OR AL,ACC_OUT2
OUT DX,AL
; RESTORE REGISTER STATUS
POP DX
POP AX
LED_INIT ENDP
; ONCE THE LED IS ARMED, IT IS TURNED ON WITH THE FOLLOWING
; PROCEDURE.
;
; INPUTS: NONE
; OUTPUTS: LED IS TURNED ON
; CALLS: NONE
; DESTROYS: FLAGS
LED_ON PROC
; PRESERVE REGISTER STATUS
PUSH AX
PUSH DX
; TURN ON THE LED
MOV DX,PAR_PORT_2
IN AL,DX
OR AL,PAR_PORT_LED
OUT DX,AL
; RESTORE REGISTER STATUS
POP DX
POP AX
LED_ON ENDP
; ONCE THE LED IS ARMED AND TURNED ON, IT IS TURNED OFF WITH THE
; FOLLOWING PROCEDURE.
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