timer_b_ex1_continuousModeCCR0.c

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//******************************************************************************
//  Timer_B, Toggle P1.0, CCR0 Cont. Mode ISR, DCO SMCLK
//
//  Description: Toggle P1.0 using software and TB_0 ISR. Toggles every
//  50000 SMCLK cycles. SMCLK provides clock source for TBCLK.
//  During the TB_0 ISR, P1.0 is toggled and 50000 clock cycles are added to
//  CCR0. TB_0 ISR is triggered every 50000 cycles. CPU is normally off and
//  used only during TB_ISR.
//  ACLK = n/a, MCLK = SMCLK = TBCLK = default DCO ~1.045MHz
//
//  Tested On: MSP430FR2311
//         ---------------
//     /|\|               |
//      | |               |
//      --|RST            |
//        |               |
//        |           P1.0|-->LED
//
//******************************************************************************
#include "driverlib.h"
 
#define COMPARE_VALUE 50000
 
void main(void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Set P1.0 to output direction
    GPIO_setAsOutputPin(
            GPIO_PORT_P1,
            GPIO_PIN0
            );
 
    //Disable the GPIO power-on default high-impedance mode to activate
    //previously configured port settings
    PMM_unlockLPM5();
 
    //Start timer in continuous mode sourced by SMCLK
    Timer_B_initContinuousModeParam initContParam = {0};
    initContParam.clockSource = TIMER_B_CLOCKSOURCE_SMCLK;
    initContParam.clockSourceDivider = TIMER_B_CLOCKSOURCE_DIVIDER_1;
    initContParam.timerInterruptEnable_TBIE = TIMER_B_TBIE_INTERRUPT_DISABLE;
    initContParam.timerClear = TIMER_B_DO_CLEAR;
    initContParam.startTimer = false;
    Timer_B_initContinuousMode(TIMER_B0_BASE, &initContParam);
 
     //Initiaze compare mode
    Timer_B_clearCaptureCompareInterrupt(TIMER_B0_BASE,
        TIMER_B_CAPTURECOMPARE_REGISTER_0);
 
    Timer_B_initCompareModeParam initCompParam = {0};
    initCompParam.compareRegister = TIMER_B_CAPTURECOMPARE_REGISTER_0;
    initCompParam.compareInterruptEnable = TIMER_B_CAPTURECOMPARE_INTERRUPT_ENABLE;
    initCompParam.compareOutputMode = TIMER_B_OUTPUTMODE_OUTBITVALUE;
    initCompParam.compareValue = COMPARE_VALUE;
    Timer_B_initCompareMode(TIMER_B0_BASE, &initCompParam);
 
    Timer_B_startCounter( TIMER_B0_BASE,
        TIMER_B_CONTINUOUS_MODE
        );
 
    __bis_SR_register(LPM0_bits + GIE);       // Enter LPM0, enable interrupts
    __no_operation();                         // For debugger
}
 
// Timer B0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMERB0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(TIMERB0_VECTOR)))
#endif
void TIMERB0_ISR (void)
{
    uint16_t compVal = Timer_B_getCaptureCompareCount(TIMER_B0_BASE,
            TIMER_B_CAPTURECOMPARE_REGISTER_0)
            + COMPARE_VALUE;
 
    GPIO_toggleOutputOnPin(
            GPIO_PORT_P1,
            GPIO_PIN0
            );
 
    // Add Offset to CCR0 [Cont mode]
    Timer_B_setCompareValue(TIMER_B0_BASE,
            TIMER_B_CAPTURECOMPARE_REGISTER_0,
            compVal
            );
}