MSP432E401Y-PWM的生成和佔空比的調整

 * MSP432E4 Empty Project
 *
 * Description: An empty project that uses DriverLib
 *
 *                MSP432E401Y
 *             ------------------
 *         /|\|                  |
 *          | |                  |
 *          --|RST               |
 *            |                  |
 *            |             PF2  |--->25%PWM
 *            |             PF3  |--->75%PWM
 *            |                  |
 *            |                  |
 * Author: 
*******************************************************************************/
/* DriverLib Includes */
#include <ti/devices/msp432e4/driverlib/driverlib.h>

/* Standard Includes */
#include <stdint.h>
#include <stdbool.h>

/* Global variable for system clock */
uint32_t getSystemClock;

/* PWM ISR */
void PWM0_0_IRQHandler(void)
{
    uint32_t getIntStatus;

    getIntStatus = MAP_PWMGenIntStatus(PWM0_BASE, PWM_GEN_1, true);

    MAP_PWMGenIntClear(PWM0_BASE, PWM_GEN_1, getIntStatus);

}


int main(void)
{

   /* Configure the system clock for 16 MHz internal oscillator */
    getSystemClock = MAP_SysCtlClockFreqSet((SYSCTL_OSC_INT |
                                             SYSCTL_USE_OSC), 16000000);

    /* The PWM peripheral must be enabled for use. */
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM0);
    while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_PWM0)));

    /* Set the PWM clock to the system clock. */
    MAP_PWMClockSet(PWM0_BASE,PWM_SYSCLK_DIV_1);

    /* Enable the clock to the GPIO Port F for PWM pins */
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    while(!MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOF));

    MAP_GPIOPinConfigure(GPIO_PF2_M0PWM2);
    MAP_GPIOPinConfigure(GPIO_PF3_M0PWM3);
    MAP_GPIOPinTypePWM(GPIO_PORTF_BASE, (GPIO_PIN_2 | GPIO_PIN_3));

    /* Configure the PWM0 to count up/down without synchronization. */
    MAP_PWMGenConfigure(PWM0_BASE, PWM_GEN_1, PWM_GEN_MODE_UP_DOWN |
                        PWM_GEN_MODE_NO_SYNC);

    /* Set the PWM period to 250Hz.  To calculate the appropriate parameter
     * use the following equation: N = (1 / f) * SysClk.  Where N is the
     * function parameter, f is the desired frequency, and SysClk is the
     * system clock frequency.
     * In this case you get: (1 / 250Hz) * 16MHz = 64000 cycles.  Note that
     * the maximum period you can set is 2^16 - 1. */
    MAP_PWMGenPeriodSet(PWM0_BASE, PWM_GEN_1, 64000);

    /* Set PWM0 PF0 to a duty cycle of 25%.  You set the duty cycle as a
     * function of the period.  Since the period was set above, you can use the
     * PWMGenPeriodGet() function.  For this example the PWM will be high for
     * 25% of the time or 16000 clock cycles (64000 / 4). */
    MAP_PWMPulseWidthSet(PWM0_BASE, PWM_OUT_2,
                     MAP_PWMGenPeriodGet(PWM0_BASE, PWM_GEN_1) / 4);

    /* Set PWM0 PF1 to a duty cycle of 75%.  You set the duty cycle as a
     * function of the period.  Since the period was set above, you can use the
     * PWMGenPeriodGet() function.  For this example the PWM will be high for
     * 7% of the time or 16000 clock cycles 3*(64000 / 4). */
    MAP_PWMPulseWidthSet(PWM0_BASE, PWM_OUT_3,
                     MAP_PWMGenPeriodGet(PWM0_BASE, PWM_GEN_1) / 4);

    MAP_IntMasterEnable();

    /* This timer is in up-down mode.  Interrupts will occur when the
     * counter for this PWM counts to the load value (64000), when the
     * counter counts up to 64000/4 (PWM A Up), counts down to 64000/4
     * (PWM A Down), and counts to 0. */
    MAP_PWMGenIntTrigEnable(PWM0_BASE, PWM_GEN_1,
                            PWM_INT_CNT_ZERO | PWM_INT_CNT_LOAD |
                            PWM_INT_CNT_AU | PWM_INT_CNT_AD);
    MAP_IntEnable(INT_PWM0_1);

    MAP_PWMIntEnable(PWM0_BASE, PWM_INT_GEN_1);

    /* Enable the PWM0 Bit 0 (PF0) and Bit 1 (PF1) output signals. */
    MAP_PWMOutputState(PWM0_BASE, PWM_OUT_2_BIT | PWM_OUT_3_BIT, true);

    /* Enables the counter for a PWM generator block. */
    MAP_PWMGenEnable(PWM0_BASE, PWM_GEN_1);

    /* Loop forever while the PWM signals are generated. */
    while(1)
    {

    }
}