MSP430G2553: Watch dog program not working

Sankareswaran Muthuraj

Part Number: MSP430G2553

Hello everyone,

Greetings!!!

My task is to reset the microcontroller if it's halted, for that, I am using a watchdog timer,

I am setting the watchdog time period as 1sec and am clearing WTD every 200ms for that I am using a timer so that the WTD won't reset every 1sec,

I wrote code, I wish to check the program so I added while(1);, the program halted here, the WDT is not resetting the microcontroller,

my program holds on while(1);, what's the problem, am I doing anything wrong? please guide me on how to solve it. I have mentioned my code below for your reference.

#include "msp430g2553.h"
unsigned int Timer1ms=0;
unsigned int count=0;
void Timer_Init();
void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;// Stop the WDT to prevent reset                // Count value for delay
  Timer_Init();
  WDTCTL = WDT_ARST_1000;  // 1 sec watchdog interval

  while(1)
  {
   //   WDTCTL = WDT_ARST_1000;
      count++;
      if(count>5000)
      {
          while(1);
          count=0;
      }
  }
}

void Timer_Init()
{
    DCOCTL = CALDCO_8MHZ;
    BCSCTL1 = CALBC1_8MHZ;
    TA0CCTL0=CCIE;
    TA0CTL=TASSEL_2+MC_1+ID_3;//SMCLK, Up mode, Divider -->1
    TA0CCR0=999;//from above calculation
    _BIS_SR(GIE);//off CPU until interrupt occurs
}

#pragma vector=TIMER0_A0_VECTOR
__interrupt void TIMER0_A0_ISR(void)
{
    Timer1ms++;
    if(Timer1ms>=200)
    {
        WDTCTL = WDTPW + WDTHOLD + WDTCNTCL;// Stop WDT
        WDTCTL =  WDT_ARST_1000;  //again 1sec reload
        Timer1ms=0;
    }
}

Thanks in advance!!

Regards,

Aravinth K.

over 4 years ago

0 Cash Hao11 over 4 years ago

TI__Mastermind 46765 points

Hi,

You do not need to add the while(1) to check your code. You can add breakpoints in the timer ISR like line 36 or line 39 to check the status.

Best regards,

Cash Hao

0 Sankareswaran Muthuraj over 4 years ago in reply to Cash Hao11

Prodigy 200 points

Hello, cash Hao11,

Thanks for your reply, I just added a breakpoint at timer line 39 it's working, but how do I manually halt the controller and check WTD is resetting the controller?

Thanks & Regards,

Aravinth K

0 Cash Hao11 over 4 years ago in reply to Sankareswaran Muthuraj

TI__Mastermind 46765 points

Hi,

If you want to check the watchdog is resetting the controller. You need to block the feed dog code.

You can refer to this example code for some ideas.

https://dev.ti.com/tirex/explore/node?node=AEBlR0c40D8-.JOaN5u6sQ__IOGqZri__LATEST

Best regards,

Cash Hao

+1 Sankareswaran Muthuraj over 4 years ago in reply to Cash Hao11

Prodigy 200 points

Hi, cash Hao11,

Thanks for your reply,

The above-mentioned code works by some modifications, Every 200ms I am clearing the WDT counter, am setting a flag after 5000 counts so that timer can't able to reset the WDT counter so WDT expires and starts reset controller. I have mentioned the code below

Thanks for your guidance

#include "msp430g2553.h"
unsigned int Timer1ms=0;
unsigned int count=0;
unsigned int temp=0;
void Timer_Init();
void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;// Stop the WDT to prevent reset                // Count value for delay
  Timer_Init(); // Initialize timer
  WDTCTL = WDT_ARST_1000;  // 1 sec watchdog interval
  count=0;
  temp=0;//flag
  while(1)
  {
      count++;
      if(count>5000)
      {
          temp=1;// after 5000 count temp will set 
          count=0;//clearing count
      }

  }
}

void Timer_Init()
{
    DCOCTL = CALDCO_8MHZ;
    BCSCTL1 = CALBC1_8MHZ;
    TA0CCTL0=CCIE;
    TA0CTL=TASSEL_2+MC_1+ID_3;//SMCLK, Up mode, Divider -->1
    TA0CCR0=999;//from above calculation
    _BIS_SR(GIE);//off CPU until interrupt occurs
}

#pragma vector=TIMER0_A0_VECTOR
__interrupt void TIMER0_A0_ISR(void)
{
    
   
     if(temp==0)// the WDT count clears every 200ms if temp is 0 else WDT won't clear itself, so WDT resets the controller
    {
        Timer1ms++;
        if(Timer1ms>=200)
        {
            WDTCTL = WDTPW + WDTCNTCL;// Clear WDT counter
            WDTCTL =  WDT_ARST_1000;  //again 1sec
            Timer1ms=0;
        }
    }
}

Thanks & regards,

Aravinth K.

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MSP430G2553: Watch dog program not working