;步進電機正轉，反轉各3圈
;***************************************************************************
;*  sxj1974@163.com		     (51c51 test web)     www.8951.com     *
;*  Create by :石學軍      www.51c51.com 更多例程請登陸網站        	   *
;***************************************************************************
org 00h
x1: mov r3,#250
start: mov r0,#00h
start1: mov p1,#0ffh
    	mov a,r0
	mov dptr,#table
	movc a,@a+dptr
	jz start
	cpl a
	mov p1,a
	call delay
	inc r0
	djnz r3,start1
	mov r3,#250
start2:	mov p1,#0ffh
 	mov r0,#05
start3:	mov a,r0
	mov dptr,#table
	movc a,@a+dptr

	jz start2
	cpl a
	mov p1,a
	call delay
	inc r0
	djnz r3,start3
	jmp x1
delay:	mov r5,#40;延時。
	d1: 	mov r6,#10
	d2:	mov r7,#18
	djnz r7,$
	djnz r6,d2
	djnz r5,d1
	ret
table:
db 03h,09h,0ch,06h
db 00
db 06h,0ch,09h,03h
db 00
end