51汇编 等周期脉宽调制pwm 子程序

            ;定时器1初始化
            MOV         TMOD,#00010000B         ;方式1，16位定时器模式

            MOV         PWM_HIGH_L,#LOW(65536 - cycle_high)
            MOV         PWM_HIGH_H,#HIGH(65536 - cycle_high)

            MOV         PWM_LOW_L,#LOW(65536 - (cycle - cycle_high))
            MOV         PWM_LOW_H,#HIGH(65536 - (cycle - cycle_high))

            SETB        P_PWM1                  ;先输出高
            MOV         TL1,PWM_HIGH_L
            MOV         TH1,PWM_HIGH_H

            SETB        ET1                     ;T1开中断
            SETB        EA                      ;开总中断
            SETB        TR1                     ;开定时器1

MAIN_LOOP:
;主循环
            SJMP        $

;**********************************************************************
;**********************************************************************
;定时器1中断服务程序
TIMER1_ISR:
            USING       1                       ; register bank 1
            PUSH        ACC
            PUSH        PSW

            JB          P_PWM1,PWM_OUT_LOW      ;如果输出为高则，输出低
            SETB        P_PWM1
            MOV         TL1,PWM_HIGH_L
            MOV         TH1,PWM_HIGH_H
            JMP         TIMER_ISR_RET

PWM_OUT_LOW:
            CLR         P_PWM1
            MOV         TL1,PWM_LOW_L
            MOV         TH1,PWM_LOW_H

TIMER_ISR_RET:
            POP         PSW
            POP         ACC
            RETI
;*********************************************************************
;
            END

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本文关键字：子程序  51单片机，单片机-工控设备 - 51单片机