12-5-5.asm

书籍8051入门篇

;PROGRAM NAME:12-5-5.ASM
$MOD51
BUFFER		DATA	20H
DEBUG		EQU	P3.0		;硬件强制除错位
SCOPE_CH1 	EQU	P3.7		;接到示波器CH1上观察
;
		ORG	0000H
		MOV	SP,#50H		;设定堆栈
		MOV	A,#00H		;累加器=00H
		MOV	BUFFER,A	;(20H)=00H
LOOP:		MOV	P1,BUFFER	;P1=(BUFFER)
		INC	BUFFER		;将BUFFER内容加上1
;
		JNB	DEBUG,TEST		
		SETB	SCOPE_CH1	;CHECK POINT=1
TEST:		LCALL	DELAY		;延迟一小段时间
		JNB	DEBUG,NEXT
		CLR	SCOPE_CH1	;CHECK POINT=0
NEXT:		SJMP	LOOP
;ROUTINE
;单纯时间延迟用
DELAY:		MOV	R0,#00H
DLY:		MOV	R1,#00H	
		DJNZ	R1,$
		DJNZ	R0,DELAY
		RET
		END