[参考译文] TM4C123GH6PM：相移 PWM 发生器

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "inc/hw_gpio.h"
#include "inc/hw_i2c.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_nvic.h"
#include "driverlib/sw_crc.h"
#include "driverlib/fpu.h"
#include "driverlib/timer.h"
#include "driverlib/gpio.h"
#include "driverlib/i2c.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/pwm.h"
#include "driverlib/eeprom.h"
#include "driverlib/flash.h"
#include "driverlib/systick.h"
#include "driverlib/qei.h"
#include "driverlib/adc.h"
#include "driverlib/uart.h"
#include "driverlib/hibernate.h"
#include "driverlib/ssi.h"




int main(void) {

    MAP_FPUEnable();
    MAP_FPULazyStackingEnable();
    MAP_SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);

    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);


    uint8_t PWM_DIV = 16;
    uint16_t PWM_SCALE = 256;
    MAP_SysCtlPWMClockSet(SYSCTL_PWMDIV_16);

    uint16_t PWM_FRQ = 100;
    uint32_t ui32SysClkFreq = MAP_SysCtlClockGet();

    uint32_t ui32PWMClock = ui32SysClkFreq / PWM_DIV;
    uint32_t ui32Load = (ui32PWMClock / PWM_FRQ) - 1;

    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM0);

    MAP_GPIOPinConfigure(GPIO_PB6_M0PWM0);
    MAP_GPIOPinConfigure(GPIO_PB7_M0PWM1);

    MAP_GPIOPinTypePWM(GPIO_PORTB_BASE, GPIO_PIN_6);
    MAP_GPIOPinTypePWM(GPIO_PORTB_BASE, GPIO_PIN_7);

    MAP_PWMGenConfigure(PWM0_BASE, PWM_GEN_0,
           (PWM_GEN_MODE_UP_DOWN |
            PWM_GEN_MODE_GEN_SYNC_LOCAL |
            PWM_GEN_MODE_DB_SYNC_LOCAL)
    );

    // MAP_PWMGenConfigure(PWM0_BASE, PWM_GEN_0, PWM_GEN_MODE_UP_DOWN | PWM_GEN_MODE_NO_SYNC);

    MAP_PWMGenPeriodSet(PWM0_BASE, PWM_GEN_0, ui32Load);

    MAP_PWMGenEnable(PWM0_BASE, PWM_GEN_0);
    MAP_PWMOutputState(PWM0_BASE, PWM_OUT_0_BIT | PWM_OUT_1_BIT, true);

    // calculate pulse width
    uint32_t ui32Width = (64 * ui32Load) / PWM_SCALE;

    MAP_PWMSyncTimeBase(PWM0_BASE, PWM_GEN_0_BIT | PWM_GEN_2_BIT | PWM_GEN_3_BIT);
    MAP_PWMSyncUpdate(PWM0_BASE, PWM_GEN_0_BIT | PWM_GEN_2_BIT | PWM_GEN_3_BIT);

    MAP_PWMPulseWidthSet(PWM0_BASE, PWM_OUT_0, ui32Width);
    MAP_PWMPulseWidthSet(PWM0_BASE, PWM_OUT_1, ui32Width * 2);


    while(true) {
        MAP_SysCtlDelay(1000);
    }
}