1.28.14 Periodic Interval Timer (PIT)

Using The Library

PIT peripheral library can be used to poll for a periodic timeout, generate periodic interrupts or generate timed waits. The following examples shows different modes of its usage.

Polling method

int main ( void )
{
    int i;
    /* Initialize all modules */
    SYS_Initialize ( NULL );

    while ( true )
    {
        for (i=0; i<10; i++) {
            while(!PIT_TimerPeriodHasExpired());
            PIT_TimerRestart();
        }
        LED_BLUE_Toggle();
        /* Maintain state machines of all polled MPLAB Harmony modules. */
        SYS_Tasks ( );
    }

    /* Execution should not come here during normal operation */

    return ( EXIT_FAILURE );
}

Interrupt Method

static void pit_callback(uintptr_t context)
{
    (void)context;
    LED_BLUE_Toggle();
}

int main ( void )
{
    /* Initialize all modules */
    SYS_Initialize ( NULL );
    
    PIT_TimerCallbackSet(pit_callback, NULL);
    
    PIT_TimerStart();

    while ( true )
    {
        /* Maintain state machines of all polled MPLAB Harmony modules. */
        SYS_Tasks ( );
    }

    /* Execution should not come here during normal operation */

    return ( EXIT_FAILURE );
}

Delay routines

int main ( void )
{
    /* Initialize all modules */
    SYS_Initialize ( NULL );
    
    PIT_TimerCallbackSet(pit_callback, NULL);
    
    PIT_TimerStart();

    while ( true )
    {
        PIT_DelayMs(1000U);
        LED_BLUE_Toggle();
        /* Maintain state machines of all polled MPLAB Harmony modules. */
        SYS_Tasks ( );
    }

    /* Execution should not come here during normal operation */

    return ( EXIT_FAILURE );
}

Library Interface

Periodic Interval Timer peripheral library provides the following interfaces:

Functions

Data types and constants