1.28.15 Periodic Interval Timer 64-bit (PIT64B)

The 64-bit Periodic Interval Timer (PIT64B) provides the operating system scheduler interrupt, as well as any periodic source of interrupt to software. It is designed to offer maximum accuracy and efficient management, even for systems with long response times.

4-bit Prescaler
Single Shot or Continuous Mode

Using The Library

PIT64B 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 )
    {
        while(!PIT64B_TimerPeriodHasExpired());
        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 timerHandler (uintptr_t context)
{    
    (void)context;
    
    LED_BLUE_Toggle(); 
}

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

    PIT64B_TimerCallbackSet(timerHandler, 0);
    PIT64B_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 );
    
    PIT64B_TimerStart();

    while ( true )
    {
        PIT64B_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 64-bit peripheral library provides the following interfaces:

Functions


Name	Description
PIT64B_TimerInitialize	Initialize PIT64B registers per user config
PIT64B_TimerRestart	Restart the PIT64B counter
PIT64B_TimerStart	Start the PIT64B counter
PIT64B_TimerStop	Stop the PIT64B counter
PIT64B_TimerPeriodSet	Set the timer period value
PIT64B_TimerPeriodGet	Get the timer period value
PIT64B_TimerCounterGet	Get the timer counter value
PIT64B_TimerFrequencyGet	Get the timer clock frequency
PIT64B_TimerPeriodHasExpired	Return whether or not the Timer Period has expired
PIT64B_DelayMs	Delays processing for x milliseconds
PIT64B_DelayUs	Delays processing for x microseconds
PIT64B_TimerCallbackSet	Register callback for PIT64B interrupt
PIT64B_ClearInterrupt	PIT64B Clear Interrupt

Data types and constants


Name	Type	Description
PIT64B_CALLBACK	Typedef	PIT64B Interrupt Callback Function definition