p3_p1.asm

来自「51系列单片机的汇编程序包」· 汇编 代码 · 共 32 行

;===================P3.3口输入，P1口输出 =====================
        ORG 0810H
J100:   MOV A,#00H
J101:   JB P3.3,J101
        MOV R2,#20H
        LCALL DELY
        JB P3.3,J101            ;P3.3电平为低吗?
J102:   JNB P3.3,J102
        MOV R2,#20H
        LCALL DELY
        JNB P3.3,J102           ;P3.3电平高吗?
        INC A                   ;加1
        PUSH ACC
        CPL A                   ;取反
        MOV P1,A                ;驱动发光二极管
        POP ACC
        AJMP J101               ;循环
;---------------------------------------------
DELY:   PUSH 02H
DEL2:   PUSH 02H
DEL3:   PUSH 02H                ;延时
DEL4:   DJNZ R2,DEL4
        POP 02H
        DJNZ R2,DEL3
        POP 02H
        DJNZ R2,DEL2
        POP 02H
        DJNZ R2,DELY
        RET
;--------------------------------------------
        END