基于51单片机的PWM脉宽调制程序代码

51汇编 等周期脉宽调制pwm 子程序2007-3-7 11:14:00
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推荐;等周期脉宽调制pwm
;晶振：12MHZ
;89C51

P_PWM1      EQU         P1.0
cycle       EQU         1000        ;PWM的周期（单位微秒），则频率为1000赫兹
cycle_high  EQU         500         ;一个周期内，PWM端口为高电平的时间(初始值）

 

            DSEG AT 20H

            ORG         40H

            PWM_HIGH_L  DATA        40H
            PWM_HIGH_H  DATA        41H         ;PWM端口为高电平时，定时器寄存器的值

            PWM_LOW_L  DATA         42H
            PWM_LOW_H  DATA         43H         ;PWM端口为高电平时，定时器寄存器的值

            ORG         60H                     ; stack origin
stack:      DS          20H                     ; stack depth


            CSEG

            ORG         0000H                   ; power on/reset vector
            jmp         on_reset