#include "Timers.h"

/**
 *  @addtogroup Timers
 *  @{
 */

// ********** private definitions **********

// ********** private data **********

static volatile U32 msTimerCount;            ///< 1ms timer counter incremented by TaskTimer.c.

/*********************************************************************//**
 * @brief
 * The initTimers function initializes the Timers unit.
 * @details \b Inputs: none
 * @details \b Outputs: msTimerCount
 * @return none
 *************************************************************************/
void initTimers( void )
{
    msTimerCount = 0;
}

/*********************************************************************//**
 * @brief
 * The incMSTimerCount function increments the ms timer count.
 * @details \b Inputs: msTimerCount
 * @details \b Outputs: msTimerCount
 * @return none
 *************************************************************************/
void incMSTimerCount( void )
{
    msTimerCount++;
}

/*********************************************************************//**
 * @brief
 * The getMSTimerCount function returns the current ms timer count.
 * @details \b Inputs: msTimerCount
 * @details \b Outputs: none
 * @return The current 32-bit millisecond timer count.
 *************************************************************************/
U32 getMSTimerCount( void )
{
    return msTimerCount;
}

/*********************************************************************//**
 * @brief
 * The didTimeout function determines whether a timeout has occurred between
 * a given start count and a given timeout period (in ms).
 * @details \b Inputs: msTimerCount
 * @details \b Outputs: none
 * @param startMSCount the ms count at the start of the timeout period
 * @param timeoutPeriod the period for the timeout (in ms)
 * @return TRUE if a timeout has occurred, FALSE if not
 *************************************************************************/
BOOL didTimeout( U32 startMSCount, U32 timeoutPeriod )
{
    BOOL result = FALSE;
    U32  currMSCount = msTimerCount;

    // no wrap
    if ( currMSCount >= startMSCount )
    {
        if ( ( currMSCount - startMSCount ) >= timeoutPeriod )
        {
            result = TRUE;
        }
    }
    // counter wrapped
    else
    {
        U32 deltaMSCount = ( 0xFFFFFFFF - startMSCount ) + currMSCount + 1;

        if ( deltaMSCount >= timeoutPeriod )
        {
            result = TRUE;
        }
    }

    return result;
}

/**@}*/