uint16_t prvTraceGetDTS()

in AVR_Dx_MPLAB.X/TraceRecorder/trcSnapshotRecorder.c [2604:2707]
68 lines of code
12 McCabe index (conditional complexity)

uint16_t prvTraceGetDTS(uint16_t param_maxDTS)
{
	static uint32_t old_timestamp = 0;
	XTSEvent* xts = 0;
	uint32_t dts = 0;
	uint32_t timestamp = 0;

	TRACE_ASSERT(param_maxDTS == 0xFF || param_maxDTS == 0xFFFF, "prvTraceGetDTS: Invalid value for param_maxDTS", 0);

	
	if (RecorderDataPtr->frequency == 0)
	{	
		if (timestampFrequency != 0)
		{
			/* If to override default TRC_HWTC_FREQ_HZ value with value set by vTraceSetFrequency */
			RecorderDataPtr->frequency = timestampFrequency / (TRC_HWTC_DIVISOR);
		} 
		else if (init_hwtc_count != (TRC_HWTC_COUNT))
		{
			/* If using default value and timer has been started. 
			Note: If the default frequency value set here would be incorrect, e.g.,
			if the timer has actually not been configured yet, override this 
			with vTraceSetFrequency.
			*/
			RecorderDataPtr->frequency = (TRC_HWTC_FREQ_HZ) / (TRC_HWTC_DIVISOR);		
		}
		/* If no override (vTraceSetFrequency) and timer inactive -> no action */
	}
	
	/**************************************************************************
	* The below statements read the timestamp from the timer port module.
	* If necessary, whole seconds are extracted using division while the rest
	* comes from the modulo operation.
	**************************************************************************/
	
	prvTracePortGetTimeStamp(&timestamp);	
	
	/***************************************************************************
	* Since dts is unsigned the result will be correct even if timestamp has
	* wrapped around.
	***************************************************************************/
	dts = timestamp - old_timestamp;
	old_timestamp = timestamp;

	if (RecorderDataPtr->frequency > 0)
	{
		/* Check if dts > 1 second */
		if (dts > RecorderDataPtr->frequency)
		{
			/* More than 1 second has passed */
			RecorderDataPtr->absTimeLastEventSecond += dts / RecorderDataPtr->frequency;
			/* The part that is not an entire second is added to absTimeLastEvent */
			RecorderDataPtr->absTimeLastEvent += dts % RecorderDataPtr->frequency;
		}
		else
		{
			RecorderDataPtr->absTimeLastEvent += dts;
		}

		/* Check if absTimeLastEvent >= 1 second */
		if (RecorderDataPtr->absTimeLastEvent >= RecorderDataPtr->frequency)
		{
			/* RecorderDataPtr->absTimeLastEvent is more than or equal to 1 second, but always less than 2 seconds */
			RecorderDataPtr->absTimeLastEventSecond++;
			RecorderDataPtr->absTimeLastEvent -= RecorderDataPtr->frequency;
			/* RecorderDataPtr->absTimeLastEvent is now less than 1 second */
		}
	}
	else
	{
		/* Special case if the recorder has not yet started (frequency may be uninitialized, i.e., zero) */
		RecorderDataPtr->absTimeLastEvent = timestamp;
	}

	/* If the dts (time since last event) does not fit in event->dts (only 8 or 16 bits) */
	if (dts > param_maxDTS)
	{
		/* Create an XTS event (eXtended TimeStamp) containing the higher dts bits*/
		xts = (XTSEvent*) prvTraceNextFreeEventBufferSlot();

		if (xts != NULL)
		{
			if (param_maxDTS == 0xFFFF)
			{
				xts->type = XTS16;
				xts->xts_16 = (uint16_t)((dts / 0x10000) & 0xFFFF);
				xts->xts_8 = 0;
			}
			else if (param_maxDTS == 0xFF)
			{
				xts->type = XTS8;
				xts->xts_16 = (uint16_t)((dts / 0x100) & 0xFFFF);
				xts->xts_8 = (uint8_t)((dts / 0x1000000) & 0xFF);
			}
			else
			{
				prvTraceError("Bad param_maxDTS in prvTraceGetDTS");
			}
			prvTraceUpdateCounters();
		}
	}

	return (uint16_t)dts & param_maxDTS;
}