#include "tiva_pwm.h"                // PWM

// PWM 初始化，频率为1000，占空比为0

    M1PWM7_init(, );

// 具体函数内容

void M1PWM7_init(uint32_t freq, float duty)

{

    //设置PWM时钟为系统时钟的1分频

    SysCtlPWMClockSet(SYSCTL_PWMDIV_1);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM1);

    //配置引脚为PWM功能

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);

    GPIOPinConfigure(GPIO_PF3_M1PWM7);

    GPIOPinTypePWM(GPIOF, Pin3);    //M1PWM7

    //配置 PWM1 Generator3·发生器

    PWMGenConfigure(PWM1_BASE, PWM_GEN_3, PWM_GEN_MODE_UP_DOWN|PWM_GEN_MODE_NO_SYNC);

    //配置 PWM1 Generator3 周期

    PWMGenPeriodSet(PWM1_BASE, PWM_GEN_3, SysCtlClockGet()/freq - );

    //配置 PWM1 Generator3 占空比

    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_7, PWMGenPeriodGet(PWM1_BASE, PWM_GEN_3)*duty - );

    //使能 PWM1 输出

    PWMOutputState(PWM1_BASE, PWM_OUT_7_BIT, true);

    //使能 PWM1 发生器模块

    PWMGenEnable(PWM1_BASE, PWM_GEN_3);

}

M1PWM7_set_duty(duty);

// 具体函数内容
void M1PWM7_set_duty(float duty)

{

    //配置 PWM1 Generator3 占空比

    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_7, PWMGenPeriodGet(PWM1_BASE, PWM_GEN_3)*duty - );

    PWMOutputState(PWM1_BASE, PWM_OUT_7_BIT, true);

    //使能 PWM1 ·发生器模块

    PWMGenEnable(PWM1_BASE, PWM_GEN_3);

}

PWMOutputState(PWM1_BASE, PWM_OUT_7_BIT, false);    // 灭灯