list p=16f876

#include 

;--------------------------

;定时计数单元

HW_TIME    EQU        0X40

;-----------------------------

;定时常数

HW_TIMECT0      EQU        0XDF;TMR0定时器时间常数，载波信号频率37.88KHz(13.2us)

HW_TIMECT1      EQU        0X64;发送信号位间隔，*(1.32ms)

HW_TIMECT3      EQU        0X31;

;-------------------------------------

        ORG    0X00        

    GOTO    HW_RECEIVE

;------------------------------------

        ORG     0X04        

        GOTO    INT

;---------------------------------------

bcf    INTCON,GIE

BCF     INTCON,T0IF     ;(T0IF)定时器溢出标志位清零

BCF    INTCON,T0IE     ;关TMR0中断(T0IE)位清零

BANKSEL    OPTION_REG

CLRF    OPTION_REG    

    BANKSEL    HW_TIME

    MOVLW    HW_TIMECT3

    MOVWF    HW_TIME

        MOVLW   HW_TIMECT0

        MOVWF   TMR0

    BANKSEL    INTCON

    BSF    INTCON,T0IE

    BSF    INTCON,GIE 

INT;中断

    movwf    W_TEMP

    movf    STATUS,0

    bcf    STATUS,RP0;working in bank0

    movwf    STATUS_TEMP

    MOVLW   HW_TIMECT0

        MOVWF   TMR0         ;重装定时常数

        BCF     INTCON,T0IF    ;清除中断溢出标志位(T0IF)

;----------------------------------------------------------------------

        DECFSZ  HW_TIME,1           ;为零，间跳，定时时间到

        GOTO    HW_LEAVE1

        MOVLW   HW_TIMECT1         ;重装时间常数

        MOVWF   HW_TIME

    BSF     HW_Sign,1

HW_LEAVE1

    BANKSEL    STATUS_TEMP

    MOVF    STATUS_TEMP,0

    MOVWF    STATUS

    MOVF    W_TEMP

    RETFIE