msp430f149 timer interrupt

Priyadharshini Mohan

Prodigy 90 points

Other Parts Discussed in Thread: MSP430F149

i tried using timerb interrupt with ACLK and continuous mode

i am not able to generate interrupt for 200ms

i cannot identify the issue

over 9 years ago

0 Clemens Ladisch over 9 years ago

Guru 319590 points

Without seeing the code, nobody else can identify the issue either.

0 old_cow_yellow over 9 years ago

Guru 58965 points

Timer-B of MSP430F149 is capable of generating 8 different IFGs. How many of these 8 did you try to generate? How do you know that there were not triggered?

Are you polling the IFGs with the interrupt turned off? If so, how did you do that?

Or, are you using ISR with the interrupt turned on? If so, how did you do that?

0 Priyadharshini Mohan over 9 years ago in reply to Clemens Ladisch

Prodigy 90 points

int main(void)
{
WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
P1DIR |= 0x07;                            // P1.0,1,2 output
P5DIR |= 0x40;                            // P5.6 output
P5SEL |= 0x40;                            // P5.6 ACLK out
DCOCTL = DCO0 + DCO1 + DCO2;     //DCO-7
BCSCTL1 = XT2OFF + RSEL0 + RSEL1 + RSEL2; //Rsel -7
BCSCTL2 = 0x00;
__delay_cycles(200);

TBCCTL0 = CCIE;                           // CCR0 interrupt enabled
TBCCTL1 = CCIE;                           // CCR1 interrupt enabled

TBCCR0 = 0x52;                             // for 5ms
TBCCR1 = 0x148;                            // for 200ms

TBCTL = TBSSEL_1 + MC_2 + ID_1;                  // ACLK, contmode, Clock/2

__bis_SR_register(GIE);       // Enter LPM0 w/ interrupt

while(1);
}

// Timer B0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMERB0_VECTOR
__interrupt void Timer_B (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMERB0_VECTOR))) Timer_B (void)
#else
#error Compiler not supported!
#endif
{
P1OUT ^= 0x01;                            // Toggle P1.0
TBCCR0 += 0x52;                          // Add Offset to CCR0
TBCCTL0 &= ~CCIFG;
//TBIV &= ~0x02;
}
// Timer B1 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMERB1_VECTOR
__interrupt void Timer_B1 (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMERB1_VECTOR))) Timer_B (void)
#else
#error Compiler not supported!
#endif
{
   switch( TBIV )
   {
      case 2:
               TBCCR1 += 0x148;                      // Add Offset to CCR1
               P1OUT ^= 0x02;                            // Toggle P1.1
               TBCCTL1 &= ~CCIFG;
               break;
      default: break;
   }
}

0 Priyadharshini Mohan over 9 years ago in reply to Priyadharshini Mohan

Prodigy 90 points

in this code i am getting interrupts for 5ms
but i am not getting for 200ms

0 Clemens Ladisch over 9 years ago in reply to Priyadharshini Mohan

Guru 319590 points

The TBIV register is not a bit mask; the (commented) statement "TBIV &= ~0x02;" would be wrong.

The interrupt for CCR0 is automatically cleared when the handler is executed (see section 12.2.6 of the User's Gude); you should not clear it again.

Reading the TBIV register automatically clears the returned interrupt; you should not clear CCIFG again.

How did you compute the CCR1 offset value? It would be correct for 20 ms …

0 Priyadharshini Mohan over 9 years ago in reply to old_cow_yellow

Prodigy 90 points

i tried all the 8 interrupts

i am toggling a port pin in the ISR

i tried for lower range but for higher range it does not work

0 Priyadharshini Mohan over 9 years ago in reply to Clemens Ladisch

Prodigy 90 points

i updated the value for 200ms but then it didnt work

0 Clemens Ladisch over 9 years ago in reply to Priyadharshini Mohan

Guru 319590 points

What exactly do you mean with "it does not work"? How are you trying to determine whether you got an interrupt?

0 Priyadharshini Mohan over 9 years ago in reply to Priyadharshini Mohan

Prodigy 90 points

TBCCTL1 = CCIE;
TBCCR1 = 0xCCC;

void __attribute__ ((interrupt(TIMERB1_VECTOR))) Timer_B (void)
case 2:
TBCCR1 += 0xCCC; // Add Offset to CCR1
P1OUT ^= 0x01; // Toggle P1.1
TBCCTL1 &= ~CCIFG;
break;

0 Dennis Eichmann over 9 years ago in reply to Priyadharshini Mohan

Guru 74080 points

Do you only measure the portpin or do you debug your code to see if the program jumps into the ISR?

0 Priyadharshini Mohan over 9 years ago in reply to Clemens Ladisch

Prodigy 90 points

i am toggling a port pin in the ISR but the operation doesnot happen

0 Priyadharshini Mohan over 9 years ago in reply to Dennis Eichmann

Prodigy 90 points

i only measure the port pin

0 Dennis Eichmann over 9 years ago in reply to Priyadharshini Mohan

Guru 74080 points

Then you should use "run to line" or set a breakpoint inside the ISR to see if it is called at all. Furthermore you could disable the other interrupt and see if that makes a difference.

0 Priyadharshini Mohan over 9 years ago in reply to Dennis Eichmann

Prodigy 90 points

when i debug the code, i have a break point in the ISR. It never comes into the ISR

0 Venu S over 9 years ago in reply to Priyadharshini Mohan

TI__Intellectual 960 points

In debug, monitor the TAR register to confirm that the Timer is active.
ie, halt the device to check the TAR value. Release the device and halt again to confirm that the TAR is changing.
This would tell you if your selected clock is active, and if the timer is enabled.

0 Venu S over 9 years ago in reply to Venu S

TI__Intellectual 960 points

If the timer is active, you could check if the TAIE bit is set (without this the Timer will not trigger an interrupt).
If the Timer is counting and the TAIE is set, check the GIE bit (without this no Interrupt will be triggered).

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msp430f149 timer interrupt