timer_b_ex3_pwm.c

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//******************************************************************************
//   Timer_B, PWM TB1-6, Up Mode, DCO SMCLK
//
//   Description: This program generates two PWM outputs on P2.6/P2.2 using
//   Timer_B configured for up mode. The value in CCR0, 512-1, defines the PWM
//   period and the values in CCR1-2 the PWM duty cycles. Using ~1048kHz SMCLK
//   as TBCLK, the timer period is ~488us.
//   ACLK = 32kHz, SMCLK = MCLK = TBCLK = default DCO ~1048kHz.
//
//   Tested On: MSP430FR2311
//             -----------------
//         /|\|              XIN|-
//          | |                 |  32kHz
//          --|RST          XOUT|-
//            |                 |
//            |       P1.6/TB0.1|--> CCR1 - 75% PWM
//            |       P1.7/TB0.2|--> CCR2 - 25% PWM
//            |                 |
//            |                 |
//            |                 |
//            |                 |
//
//******************************************************************************
#include "driverlib.h"
 
void main(void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    GPIO_setAsPeripheralModuleFunctionOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN6 | GPIO_PIN2,
        GPIO_SECONDARY_MODULE_FUNCTION
        );
 
    //Disable the GPIO power-on default high-impedance mode to activate
    //previously configured port settings
    PMM_unlockLPM5();
 
    //Start timer
    Timer_B_initUpModeParam param = {0};
    param.clockSource = TIMER_B_CLOCKSOURCE_SMCLK;
    param.clockSourceDivider = TIMER_B_CLOCKSOURCE_DIVIDER_1;
    param.timerPeriod = 511;
    param.timerInterruptEnable_TBIE = TIMER_B_TBIE_INTERRUPT_DISABLE;
    param.captureCompareInterruptEnable_CCR0_CCIE =
        TIMER_B_CCIE_CCR0_INTERRUPT_DISABLE;
    param.timerClear = TIMER_B_DO_CLEAR;
    param.startTimer = true;
    Timer_B_initUpMode(TIMER_B0_BASE, &param);
 
    //Initialize compare mode to generate PWM1
    Timer_B_initCompareModeParam param1 = {0};
    param1.compareRegister = TIMER_B_CAPTURECOMPARE_REGISTER_1;
    param1.compareInterruptEnable = TIMER_B_CAPTURECOMPARE_INTERRUPT_DISABLE;
    param1.compareOutputMode = TIMER_B_OUTPUTMODE_RESET_SET;
    param1.compareValue = 383;
    Timer_B_initCompareMode(TIMER_B0_BASE, &param1);
    
    //Initialize compare mode to generate PWM2
    Timer_B_initCompareModeParam param2 = {0};
    param2.compareRegister = TIMER_B_CAPTURECOMPARE_REGISTER_2;
    param2.compareInterruptEnable = TIMER_B_CAPTURECOMPARE_INTERRUPT_DISABLE;
    param2.compareOutputMode = TIMER_B_OUTPUTMODE_RESET_SET;
    param2.compareValue = 128;
    Timer_B_initCompareMode(TIMER_B0_BASE, &param2);
 
     _BIS_SR(LPM0_bits + GIE);                 // CPU off
}