SM320F2808-EP: SW watchdog design question

Jeffrey Masse

Part Number: SM320F2808-EP
Other Parts Discussed in Thread: C2000WARE

I currently am servicing the watchdog timer within a CPU interrupt timer. Is this a common way to handle the watchdog timer or is there a more generally accepted practice of how to setup the ServiceDog()?

ConfigCpuTimer(&CpuTimer0, 100, 5000); // 5mSec to service a 13.1mSec watchdog timer

StartCpuTimer0();
// Start watch-dogging
EnableDog();

__interrupt void cpu_timer0_isr(void)
{
// 5ms to service a 13.1mSec watchdog
CpuTimer0.InterruptCount++;
// kick the dog
ServiceDog();
// Acknowledge this interrupt to receive more interrupts from group 1
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
if(CpuTimer0.InterruptCount >= 200)
{
GpioDataRegs.GPBTOGGLE.bit.GPIO34 = 1;
CpuTimer0.InterruptCount = 0;
}
}

over 2 years ago

0 Ozino Odharo over 2 years ago

TI__Genius 14261 points

Hi,

I recommend checking out the watchdog example available in C2000Ware for an example on how to configure a watchdog ISR and how to use the ServiceDog(). I would then also check out the CPU Timer INT example. Once you've configured the watchdog, you can then define the CPU Timer INT.

0 Jeffrey Masse over 2 years ago in reply to Ozino Odharo

Intellectual 360 points

Thanks Ozino, as you can see by my code, I have figured out how to do what you recommended. I was more curious about a best practice approach. Is using ISRs common for servicing the watchdog or do designers put KickWDog( ) in tasks and various code locations?

0 Ozino Odharo over 2 years ago in reply to Jeffrey Masse

TI__Genius 14261 points

Jeffery,

It is common to ISRs to service the watchdog. Though I've seen other function used in simpler examples or applications. I would say it is application or use case dependent.

+1 Jeffrey Masse over 2 years ago in reply to Ozino Odharo

Intellectual 360 points

From co-worker:
I think you need to kick it from your code. If you just have the ISR do it, your main loop could die and the ISR would continue on its merry way kicking the watchdog. We have, in the past, put flags for each thread in the main code. ISR could kick the dog if all flags are set, then clear the flags

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SM320F2808-EP: SW watchdog design question