SYSBIOS Timer and/or Clock jitter issue

Hi Eric,

Can you provide a sample application that demonstrates this? Also which version of SYS/BIOS are you using 1.1.06 does not make sense. It should be 6.xx.xx.xx.

Todd

Hi Todd,

Sorry for my mistakes.

SYS/BIOS : 6.42.02.29

Ind SDK : 1.1.0.6

NDK : 2.24.03.35

Below is the code :

void createAxisService(void)
{
	// Init Error
	Error_Block eb;
	Error_init(&eb);

#ifndef USE_TIMER
	Clock_Params clockParams;
	Clock_Params_init(&clockParams);
	clockParams.period = OS_TICKS_IN_MILLI_SEC;	// every 1 ms
	clockParams.startFlag = false;	// do not start immediately
	hAxisService = Clock_create((Clock_FuncPtr) AxisService, 4* OS_TICKS_IN_MILLI_SEC, &clockParams, &eb);
	if (hAxisService == NULL)
	{
		System_abort("Clock0 create failed");
	}
#else
	// Setup timer clock
	DMTimer6ModuleClkConfig();

	/*Timer setup init*/
	Timer_Params timerParams;
	Timer_Params_init(&timerParams);

	/*This is irrelevant since timeout value is received from the supervisor*/
	timerParams.period 		= 1000;
	timerParams.periodType	= Timer_PeriodType_MICROSECS;
	//timerParams.arg = 1;
	/*24 Mhz, care must be taken to ensure that this value
	 * is modified if the source clock frequency is modified */
	timerParams.extFreq.lo 	= 24000000;
	timerParams.extFreq.hi 	= 0;
	timerParams.startMode 	= Timer_StartMode_USER;

	timerParams.instance->name = "AxisService";

	uint8_t timerNum = 6-2; // Timer ID is 0 to 5, corresponding to timer 2 to 7
	hAxisService = Timer_create(timerNum, AxisService, &timerParams,  &eb); /* DMTIMER6 */

	if (hAxisService == NULL) {
	 System_abort("Timer create failed");
	}
#endif
}

Void AxisService(UArg arg0)
{
	sStatus sStatus;
	sCommande cmd_NC;

        // save the timer of a cycle loop
	cmd_NC.arguments[0] = (float)Timer7Get();
	Timer7Reset();


	// RX & TX data structure
	MotionDataStruct MotionDataRx[NUMAXIS], MotionDataTx[NUMAXIS];

	// If we are waiting for a new trajectory element, go to check it in the mailbox
	if(endOfTraj == true)
	{
		if(!Mailbox_pend(mbTrajElem_NC, &TrajElem_NC, BIOS_NO_WAIT))
		{
			// No more traj ? send the last command
			RTCURawRequest(rtcuTx, rtcuRx);

                        // Send timer information to the uart queue to debug
			cmd_NC.arguments[1] = (float)Timer7Get();
			cmd_NC.arguments[2] = (float)MotionDataRx[1].ival1;
			cmd_NC.arguments[3] = (float)MotionDataRx[1].ival2;
			saveCmdMbox_NC(&cmd_NC,BIOS_NO_WAIT);

			// finish here
			return;
		}
		// starting a new trajectory
		polyTn = 0.0;
		polyIndex = 0;
		endOfTraj = false;
	}



	// Send the command with TX data and get motion data
	RTCURawRequest(rtcuTx, rtcuRx);


// Send timer information to the uart queue to debug
	cmd_NC.arguments[1] = (float)Timer7Get();  // save the time inside the service loop
	cmd_NC.arguments[2] = (float)MotionDataRx[1].ival1;
	cmd_NC.arguments[3] = (float)MotionDataRx[1].ival2;
	saveCmdMbox_NC(&cmd_NC,BIOS_NO_WAIT);
}

A couple things...

1. I'm assuming you are starting the Clock or Timer somewhere else.

2. What are the Timer7Get and Timer7Reset functions doing? Is this a different timer that you are using as a stopwatch. Is this managed by the kernel or by you? Could this timer be wrapping and giving incorrect information?

3. Does the 1 second delay pattern repeat?

4. Did you disable interrupts any place and could the duration that interrupts are disabled possibly be causing this?

Todd

1. Yes I start the clock or the timer when I know peripheral are initialized

2. The Timer7Get and Timer7Reset are function to put the dmtimer 7 to zero and get the value. I use dmtimer 6 to calculate de delay. There is no interrupt, it is use un free run.

void InitTimer7(void)
{
	DMTimer7ModuleClkConfig();
	DMTimerPreScalerClkDisable(SOC_DMTIMER_7_REGS);
	DMTimerReset(SOC_DMTIMER_7_REGS);
	DMTimerCounterSet(SOC_DMTIMER_7_REGS, 0);
	DMTimerModeConfigure(SOC_DMTIMER_7_REGS, DMTIMER_ONESHOT_NOCMP_ENABLE);
//	DMTimerReloadSet(SOC_DMTIMER_7_REGS, 0xffffffff);
//	DMTimerIntDisable(SOC_DMTIMER_7_REGS, DMTIMER_INT_OVF_EN_FLAG);
//	DMTimerIntStatusClear(SOC_DMTIMER_7_REGS, DMTIMER_INT_OVF_EN_FLAG);
	DMTimerEnable(SOC_DMTIMER_7_REGS);
}

uint32_t Timer7Get (void)
{
	return (DMTimerCounterGet(SOC_DMTIMER_7_REGS));
}

void Timer7Reset (void)
{
	DMTimerCounterSet(SOC_DMTIMER_7_REGS, 0);// reset counter value
}

3. I don't know if the delay pattern is repeated because I entering in fatal error with my peripherals connected  to, so all system stop.

4. In no case I disable interrupt or swi or task. All the system is sync by semaphore for task management.

Let's focus on the Timer case. Your createAxisService function is going to be ran in the context of the interrupt. Can you add another Timer7Get at the end of createAxisService and do the math to make sure that it is not taking more time than you expect.

Can you look in ROV to see what other interrupts are present in the system and post a snapshot of it (Hwi->Detailed in ROV). Also, select BIOS->Scan for errors... to make sure nothing fishy is going on.

I'm assuming that no other code is calling Timer7Get, Timer7Reset or playing with the DMTimer7.

I don't understand about the timer7 question. The "createAxisService" is called only once. The "AxisService" is called periodically by the timer each 1ms. What is important is the service must be call with a minimum of jitter between 2 service. The time between the create and the service isn't important.

Here is the ROV HWI screenshot:

For the ROV Scan BIOS, there is nothing wrong.

For the call of Timer7 get and reset, yes, indeed they are called only in the service loop.

Regards.

My bad... I meant adding another Timer7Get at the end of "AxisService" and confirm the "AxisService" function is running as quickly as you expect it to (e.g. < 1ms). If this takes a long time to run, the next one will be delayed. Can you show the ROV for the timers also?

Hi Todd,

Log : (t I+o = time between two calls of clock, t I = time of execution of the axisservice)

t i+o = 0.001006s ,t  i = 0.000005s, ival1 = 0, ival2 = 0

When I my program stuck, "t i+o" is more than 1 seconde and "t  i" is keeping the same value (approx. 5us).

I took screenshot when I test with a clock(swi) instead of timer(hwi):

clock :

timer :

Hi Todd

I look in the Hwi and I can find something weird.

The problem is I don't have a Hwi in the compiler task and I when look in the Swi, there is a mention of compiler task too... This task wait a mailbox without doing anything else. Why a Hwi is created ?

thanks