Hi,
I am trying to write a program that will take 450 analog signals from
pin 6. I want the program to take the signal when at a specific rate
so iam using TimerA interrupts to start the A/D conversions. But for
some reason when the ISR is called the program keeps looping inside
the ISR. However it doesnt stay inside the ISR all the time. Does
any1 Know what the problem is? Thank You!
Tamim
#include <io430x14x.h>
#include <intrinsics.h>
#define AE_Samples 450
int i;
static unsigned int AE_results[AE_Samples];
void main(void)
{
__disable_interrupt();
WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer
P6SEL |= 0x01; // Enable A/D channel A0
CCTL0 = CM_0; // No Captures, enable
compare mode
ADC12CTL0 = ADC12ON+SHT0_2; // Turn on ADC12, set
sampling time
ADC12MCTL0 = SREF_2; // The voltage reference is
applied externally through Pin Vr+
ADC12CTL1 = SHP; // Use sampling timer
TACTL = TASSEL_1+MC_1+TAIE; // Timer_A setup, UP
mode,Crystal,Enable Time_A interrupt
__enable_interrupt(); // Re-enable interrupts
for(i=0;i<AE_Samples;i++)
{
TACCTL0_bit.CCIFG = 0; // I must explicity clear CCIFG so that
other things wont cause interrupts
TACCTL0 = CCIE; //Enable interupts
TACCR0 = 0xFF; // Compare value (Depends on
the Crystal used),Enable CCIFG at this value
//The value depends on number
of clock cycles passed and crystal used
}
}
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A0_ISR(void) // The set delay has
passed i.e. the timer has counted
{
ADC12CTL0 |= ENC; // Enable conversions
ADC12CTL0 |= ADC12SC; // Start conversion
ADC12CTL0 &= ~ENC; // Clear ENC bit, SET
BREAKPOINT HERE
while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY?
AE_results[i] = ADC12MEM0; // Move results, IFG is
cleared
TACCTL0_bit.CCIFG = 0;
}
Timer A and Interrupt Problem
Started by ●January 7, 2005
Reply by ●January 7, 20052005-01-07
projecttamim wrote:
> #pragma vector=TIMERA0_VECTOR
> __interrupt void Timer_A0_ISR(void) // The set delay has
> passed i.e. the timer has counted
> {
> ADC12CTL0 |= ENC; // Enable conversions
> ADC12CTL0 |= ADC12SC; // Start conversion
>
> ADC12CTL0 &= ~ENC; // Clear ENC bit, SET
> BREAKPOINT HERE
> while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY?
> AE_results[i] = ADC12MEM0; // Move results, IFG is
> cleared
> TACCTL0_bit.CCIFG = 0;
>
>
> }
It is good programming practice to include a return(); statement, even
in functions that do not or cannot return a value. This might prove
helpful in your case...
~Dave
Reply by ●January 7, 20052005-01-07
Tamin,
in your code I didn't see the clock initialization routine, which is
very important! Take a look at chapter 4 of the user's guide. Have you
checked what clock sources are you using for timer A and ADC? Are they
according to your hardware?
Regards,
Adriano.
projecttamim wrote:
>
> Hi,
> I am trying to write a program that will take 450 analog signals from
> pin 6. I want the program to take the signal when at a specific rate
> so iam using TimerA interrupts to start the A/D conversions. But for
> some reason when the ISR is called the program keeps looping inside
> the ISR. However it doesnt stay inside the ISR all the time. Does
> any1 Know what the problem is? Thank You!
>
> Tamim
>
> #include <io430x14x.h>
> #include <intrinsics.h>
> #define AE_Samples 450
>
> int i;
>
> static unsigned int AE_results[AE_Samples];
>
> void main(void)
> {
> __disable_interrupt();
> WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer
>
> P6SEL |= 0x01; // Enable A/D channel A0
> CCTL0 = CM_0; // No Captures, enable
> compare mode
> ADC12CTL0 = ADC12ON+SHT0_2; // Turn on ADC12, set
> sampling time
> ADC12MCTL0 = SREF_2; // The voltage reference is
> applied externally through Pin Vr+
> ADC12CTL1 = SHP; // Use sampling timer
>
> TACTL = TASSEL_1+MC_1+TAIE; // Timer_A setup, UP
> mode,Crystal,Enable Time_A interrupt
>
> __enable_interrupt(); // Re-enable interrupts
>
> for(i=0;i<AE_Samples;i++)
> {
>
> TACCTL0_bit.CCIFG = 0; // I must explicity clear CCIFG so that
> other things wont cause interrupts
> TACCTL0 = CCIE; //Enable interupts
> TACCR0 = 0xFF; // Compare value (Depends on
> the Crystal used),Enable CCIFG at this value
> //The value depends on number
> of clock cycles passed and crystal used
> }
>
> }
>
> #pragma vector=TIMERA0_VECTOR
> __interrupt void Timer_A0_ISR(void) // The set delay has
> passed i.e. the timer has counted
> {
> ADC12CTL0 |= ENC; // Enable conversions
> ADC12CTL0 |= ADC12SC; // Start conversion
>
> ADC12CTL0 &= ~ENC; // Clear ENC bit, SET
> BREAKPOINT HERE
> while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY?
> AE_results[i] = ADC12MEM0; // Move results, IFG is
> cleared
> TACCTL0_bit.CCIFG = 0;
>
>
> }
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
Reply by ●January 13, 20052005-01-13
Arggh! Why are you still trying to run your A/D sample from within the
TimerA ISR? In my last response I pojn ted out to you thagt there is a
timer trigger mode that enables A/D samples to be directly triggered by
the timer without all the bit polling and other half assed stuff. In
your first post you didin't mention wanting to run 450 samples, but
adding a counter to the timer compare ISR is simple. You need to study
the timer triggered mode of the ADC. It is clearly explained in the user
Guide, and I, and others have desfribed it and posted sample code in the
past.
Al
projecttamim wrote:
>
> Hi,
> I am trying to write a program that will take 450 analog signals from
> pin 6. I want the program to take the signal when at a specific rate
> so iam using TimerA interrupts to start the A/D conversions. But for
> some reason when the ISR is called the program keeps looping inside
> the ISR. However it doesnt stay inside the ISR all the time. Does
> any1 Know what the problem is? Thank You!
>
> Tamim
>
> #include <io430x14x.h>
> #include <intrinsics.h>
> #define AE_Samples 450
>
> int i;
>
> static unsigned int AE_results[AE_Samples];
>
> void main(void)
> {
> __disable_interrupt();
> WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer
>
> P6SEL |= 0x01; // Enable A/D channel A0
> CCTL0 = CM_0; // No Captures, enable
> compare mode
> ADC12CTL0 = ADC12ON+SHT0_2; // Turn on ADC12, set
> sampling time
> ADC12MCTL0 = SREF_2; // The voltage reference is
> applied externally through Pin Vr+
> ADC12CTL1 = SHP; // Use sampling timer
>
> TACTL = TASSEL_1+MC_1+TAIE; // Timer_A setup, UP
> mode,Crystal,Enable Time_A interrupt
>
> __enable_interrupt(); // Re-enable interrupts
>
> for(i=0;i<AE_Samples;i++)
> {
>
> TACCTL0_bit.CCIFG = 0; // I must explicity clear CCIFG so that
> other things wont cause interrupts
> TACCTL0 = CCIE; //Enable interupts
> TACCR0 = 0xFF; // Compare value (Depends on
> the Crystal used),Enable CCIFG at this value
> //The value depends on number
> of clock cycles passed and crystal used
> }
>
> }
>
> #pragma vector=TIMERA0_VECTOR
> __interrupt void Timer_A0_ISR(void) // The set delay has
> passed i.e. the timer has counted
> {
> ADC12CTL0 |= ENC; // Enable conversions
> ADC12CTL0 |= ADC12SC; // Start conversion
>
> ADC12CTL0 &= ~ENC; // Clear ENC bit, SET
> BREAKPOINT HERE
> while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY?
> AE_results[i] = ADC12MEM0; // Move results, IFG is
> cleared
> TACCTL0_bit.CCIFG = 0;
>
>
> }
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
Reply by ●January 13, 20052005-01-13
This may be elegant(and it is) but now you depend on TA ISR being enabled. What about a situation where initial calibration involves a number of A/D conversions before any timer in enabled. Karl, >From: onestone <onestone@ones...> >Reply-To: msp430@msp4... >To: msp430@msp4... >Subject: Re: [msp430] Timer A and Interrupt Problem >Date: Thu, 13 Jan 2005 22:00:37 +1030 > > >Arggh! Why are you still trying to run your A/D sample from within the >TimerA ISR? In my last response I pojn ted out to you thagt there is a >timer trigger mode that enables A/D samples to be directly triggered by >the timer without all the bit polling and other half assed stuff. In >your first post you didin't mention wanting to run 450 samples, but >adding a counter to the timer compare ISR is simple. You need to study >the timer triggered mode of the ADC. It is clearly explained in the user >Guide, and I, and others have desfribed it and posted sample code in the >past. > >Al > >projecttamim wrote: > > > > > Hi, > > I am trying to write a program that will take 450 analog signals from > > pin 6. I want the program to take the signal when at a specific rate > > so iam using TimerA interrupts to start the A/D conversions. But for > > some reason when the ISR is called the program keeps looping inside > > the ISR. However it doesnt stay inside the ISR all the time. Does > > any1 Know what the problem is? Thank You! > > > > Tamim > > > > #include <io430x14x.h> > > #include <intrinsics.h> > > #define AE_Samples 450 > > > > int i; > > > > static unsigned int AE_results[AE_Samples]; > > > > void main(void) > > { > > __disable_interrupt(); > > WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer > > > > P6SEL |= 0x01; // Enable A/D channel A0 > > CCTL0 = CM_0; // No Captures, enable > > compare mode > > ADC12CTL0 = ADC12ON+SHT0_2; // Turn on ADC12, set > > sampling time > > ADC12MCTL0 = SREF_2; // The voltage reference is > > applied externally through Pin Vr+ > > ADC12CTL1 = SHP; // Use sampling timer > > > > TACTL = TASSEL_1+MC_1+TAIE; // Timer_A setup, UP > > mode,Crystal,Enable Time_A interrupt > > > > __enable_interrupt(); // Re-enable interrupts > > > > for(i=0;i<AE_Samples;i++) > > { > > > > TACCTL0_bit.CCIFG = 0; // I must explicity clear CCIFG so that > > other things wont cause interrupts > > TACCTL0 = CCIE; //Enable interupts > > TACCR0 = 0xFF; // Compare value (Depends on > > the Crystal used),Enable CCIFG at this value > > //The value depends on number > > of clock cycles passed and crystal used > > } > > > > } > > > > #pragma vector=TIMERA0_VECTOR > > __interrupt void Timer_A0_ISR(void) // The set delay has > > passed i.e. the timer has counted > > { > > ADC12CTL0 |= ENC; // Enable conversions > > ADC12CTL0 |= ADC12SC; // Start conversion > > > > ADC12CTL0 &= ~ENC; // Clear ENC bit, SET > > BREAKPOINT HERE > > while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY? > > AE_results[i] = ADC12MEM0; // Move results, IFG is > > cleared > > TACCTL0_bit.CCIFG = 0; > > > > > > } > > > > > > > > > > > > > > . > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > >. > > >Yahoo! Groups Links > > > > > > > _________________________________________________________________ Dont just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/
Reply by ●January 14, 20052005-01-14
Karl Adler wrote: > This may be elegant(and it is) but now you depend on TA ISR being enabled. > What about a situation where initial calibration involves a number of A/D > conversions before any timer in enabled. > Karl, Sorry Karl, I don't get this. The designer is free to enable and disable the Timer ISR at will. Therefore he/she is free to enable it just to accomplish this 'calibration period', then free to disable it until required later. The timer is running anyway, the AD is ON, therefore it isn't a question of power consumption. In fact examining the code suggests it is simply a case of poor understanding of how to do this task efficiently. Why would you NOT want to enable the TIMER ISR? since you have very fine control over its application? Al > > >>From: onestone <onestone@ones...> >>Reply-To: msp430@msp4... >>To: msp430@msp4... >>Subject: Re: [msp430] Timer A and Interrupt Problem >>Date: Thu, 13 Jan 2005 22:00:37 +1030 >> >> >>Arggh! Why are you still trying to run your A/D sample from within the >>TimerA ISR? In my last response I pojn ted out to you thagt there is a >>timer trigger mode that enables A/D samples to be directly triggered by >>the timer without all the bit polling and other half assed stuff. In >>your first post you didin't mention wanting to run 450 samples, but >>adding a counter to the timer compare ISR is simple. You need to study >>the timer triggered mode of the ADC. It is clearly explained in the user >>Guide, and I, and others have desfribed it and posted sample code in the >>past. >> >>Al >> >>projecttamim wrote: >> >> >>>Hi, >>>I am trying to write a program that will take 450 analog signals from >>>pin 6. I want the program to take the signal when at a specific rate >>>so iam using TimerA interrupts to start the A/D conversions. But for >>>some reason when the ISR is called the program keeps looping inside >>>the ISR. However it doesnt stay inside the ISR all the time. Does >>>any1 Know what the problem is? Thank You! >>> >>>Tamim >>> >>>#include <io430x14x.h> >>>#include <intrinsics.h> >>>#define AE_Samples 450 >>> >>>int i; >>> >>>static unsigned int AE_results[AE_Samples]; >>> >>>void main(void) >>>{ >>> __disable_interrupt(); >>> WDTCTL = WDTPW+WDTHOLD; // Stop watchdog timer >>> >>> P6SEL |= 0x01; // Enable A/D channel A0 >>> CCTL0 = CM_0; // No Captures, enable >>>compare mode >>> ADC12CTL0 = ADC12ON+SHT0_2; // Turn on ADC12, set >>>sampling time >>> ADC12MCTL0 = SREF_2; // The voltage reference is >>>applied externally through Pin Vr+ >>> ADC12CTL1 = SHP; // Use sampling timer >>> >>> TACTL = TASSEL_1+MC_1+TAIE; // Timer_A setup, UP >>>mode,Crystal,Enable Time_A interrupt >>> >>> __enable_interrupt(); // Re-enable interrupts >>> >>> for(i=0;i<AE_Samples;i++) >>> { >>> >>> TACCTL0_bit.CCIFG = 0; // I must explicity clear CCIFG so that >>>other things wont cause interrupts >>> TACCTL0 = CCIE; //Enable interupts >>> TACCR0 = 0xFF; // Compare value (Depends on >>>the Crystal used),Enable CCIFG at this value >>> //The value depends on number >>>of clock cycles passed and crystal used >>> } >>> >>>} >>> >>> #pragma vector=TIMERA0_VECTOR >>> __interrupt void Timer_A0_ISR(void) // The set delay has >>>passed i.e. the timer has counted >>> { >>> ADC12CTL0 |= ENC; // Enable conversions >>> ADC12CTL0 |= ADC12SC; // Start conversion >>> >>> ADC12CTL0 &= ~ENC; // Clear ENC bit, SET >>>BREAKPOINT HERE >>> while ((ADC12CTL1 & ADC12BUSY) == 1); // ADC12BUSY? >>> AE_results[i] = ADC12MEM0; // Move results, IFG is >>>cleared >>> TACCTL0_bit.CCIFG = 0; >>> >>> >>> } >>> >>> >>> >>> >>> >>> >>>. >>> >>> >>>Yahoo! Groups Links >>> >>> >>> >>> >>> >>> >>> >>> >> >> >> >>. >> >> >>Yahoo! Groups Links >> >> >> >> >> >> >> > > > _________________________________________________________________ > Dont just search. Find. Check out the new MSN Search! > http://search.msn.click-url.com/go/onm00200636ave/direct/01/ > > > > . > > > Yahoo! Groups Links > > > > > > > >
