timer_b_ex2_overflowISR.c

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//******************************************************************************
//  Timer_B, Toggle P1.0, Overflow ISR, 32kHz ACLK
//
//  Description: Toggle P1.0 using software and the Timer_B overflow ISR.
//  In this example an ISR triggers when TB overflows. Inside the ISR P1.0
//  is toggled. Toggle rate is exactly 0.25Hz = [32kHz/FFFFh]/2. Proper use of the
//  TBxIV interrupt vector generator is demonstrated.
//  ACLK = TBCLK = 32kHz, MCLK = SMCLK = default DCO ~ 1.045MHz
//
//  Tested On: MSP430FR2311
//         ---------------
//     /|\|               |
//      | |               |
//      --|RST            |
//        |               |
//        |           P1.0|-->LED
//******************************************************************************
#include "driverlib.h"
 
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();
 
    Timer_B_clearTimerInterrupt(TIMER_B0_BASE);
 
    Timer_B_initContinuousModeParam param = {0};
    param.clockSource = TIMER_B_CLOCKSOURCE_ACLK;
    param.clockSourceDivider = TIMER_B_CLOCKSOURCE_DIVIDER_1;
    param.timerInterruptEnable_TBIE = TIMER_B_TBIE_INTERRUPT_ENABLE;
    param.timerClear = TIMER_B_DO_CLEAR;
    param.startTimer = false;
    Timer_B_initContinuousMode(TIMER_B0_BASE, &param);
 
    Timer_B_startCounter(TIMER_B0_BASE,
            TIMER_B_CONTINUOUS_MODE
            );
 
    __bis_SR_register(LPM3_bits + GIE);       // Enter LPM3, enable interrupts
    __no_operation();                         // For debugger
}
 
// Timer0_B7 Interrupt Vector (TBxIV) handler
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMER0_B1_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(TIMER0_B1_VECTOR)))
#endif
void TIMER0_B1_ISR(void)
{
    /* Any access, read or write, of the TBxIV register automatically resets the
       highest "pending" interrupt flag. */
    switch( __even_in_range(TB0IV,14) )
    {
        case TBIV__NONE:    break;      // No interrupt
        case TBIV__TBCCR1:  break;      // CCR1 not used
        case TBIV__TBCCR2:  break;      // CCR2 not used
        case TBIV__TBCCR3:  break;      // CCR3 not used
        case TBIV__TBCCR4:  break;      // CCR4 not used
        case TBIV__TBCCR5:  break;      // CCR5 not used
        case TBIV__TBCCR6:  break;      // CCR6 not used
        case TBIV__TBIFG:               // Overflow
                           //Toggle P1.0
                           GPIO_toggleOutputOnPin(
                                   GPIO_PORT_P1,
                                   GPIO_PIN0
                                   );
                           break;
        default: break;
    }
}