LPC4357: watchdog can't reset

[hbxiao168]

I am trying to implement the WWDT function in the LPC4357,  Watchdog Register is configured successful, watchdog reset can performed when not feed. The can always reset , but as this run about 2 hours, the watchdog can't reset? 

void WatchDogStart( uint32 Xms ) 
{
WDTC = (12000000*Xms)/(1000*4); // Xms=5000, 5s reset
WDWARNINT = 32;
WDMOD = WDEN|WDRESET|WDINT;
WDFEED = 0xAA; /* Feeding sequence */
WDFEED = 0x55;
NVIC_EnableIRQ(WWDT_IRQn);
return;
}

Regards,

Haibin Xiao

[Alice_Yang]

Hello haibin xiao ,

Sorry I was  wondering what's he meaning of  "but as this run about 2 hours, the watchdog can't reset?".

Do you mean Watchdog work well only in 2 hours, after that, it can' work well ? Could you please tell me detail

about this case, also show the more code about how to use Wtachdog .

And there is a demo code about Watchdog under LPCOpen, you can download it and have a look:

LPCOpen Software for LPC43XX|NXP 

Hope it helps,

Have a great day,
TIC

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[hbxiao168]

Thanks, I mean Watchdog work well only in 2 hours, after that, it can' work well. 

void WatchDogStart( uint32 Xms ) 
{
WDTC = (12000000*Xms)/(1000*4); // Xms=5000, 5s reset
WDWARNINT = 32;
WDMOD = WDEN|WDRESET|WDINT;
WDFEED = 0xAA; /* Feeding sequence */
WDFEED = 0x55;
NVIC_EnableIRQ(WWDT_IRQn);
return;
}

void WatchDogClear( void )
{
__disable_irq();
WDFEED = 0xAA; /* Feeding sequence */
WDFEED = 0x55;
__enable_irq();
return;
}

int main(void)
{
uint32 i = 0;

CGU_Init();
WatchDogStart(5000);

Timer0Initialize();
SetDefaultUart1();
Init_LED();
HC595SendData(0xff);
DelayMS(500);
while(1)
{

   for(i=0;i<8;i++)
   {
      HC595SendData(~(0x1<<i));
      DelayMS(500);
   }
   HC595SendData(0xFF);
   //WatchDogClear();

}

return 0;
}

it can reset in 2 hours, after that, it can‘t work well.

Regards,

Haibin Xiao

[bernhardfink]

If it is always the same period of 2 hours, then the system runs into a kind of boundary. This could be a maximum counter value (for example you defined a variable as "int", but still continue to increment the value  when reaching the maximum.

It could also be a memory leak, for example an overflow of the heap, which takes effect after a specific time.

You should implement some debug code in the loop, just make some checks whether the watchdog is (still) enabled. Also give it a try without the watchdog interrupt.

Regards,

Bernhard.

[hbxiao168]

Thank you！