Triggering ADC SOCA and SOCB from ePWM1 (up/down count mode)

Hi Mario,

I think the basic setup that you want would be:

SOC0: Triggered from ePWM1 SOCA, sets ADCINT1 flag (conversion result will be in ADCRESULT0)

SOC1: Triggered from ePWM1 SOCB, sets ADCINT2 flag (conversion result will be in ADCRESULT1)

Depending on how often you need to do calculations with the ADC results, you could use both ADCINT1 and ADCINT2 to trigger separate ISRs.  Otherwise, it would be fine to read both conversion results in one ISR, since the conversion results get stored in separate registers.  

Please also read the device errata, particularly the first sample erratum;  because of this, you either need to double sample for each of these ePWM conversions, or set the ADC in non-overlap and clock/2 mode (probably you will want the second).

Another hint: if you look in ControlSUITE in the below directory, you will find the resources for all of our system kits (including various DC-DC kits).  If you grab some of the code from one of the DC-DC kits, it may be informative/a good starting point.  Note that if you can't find 28027 code (launchpad device), F2803x is almost identical from a software perspective.  

C:\TI\controlSUITE\development_kits

Hi Devin,

thank you for spending your time with my questions..

Yes, the idea is to read both sample in one ISR. How can I redirect both interruptions to the same ISR function?

I wont be able to look at that directory because I'm working under Debian Wheezy, is there any code available in the web?

I'll take a look at device errata cause the things you told "..the ADC in non-overlap and clock/2 mode..." doesn't make the bell ring in my head.

Regards,

Mário

Devin,

it seems that my ISR is now being called twice in each PWM period, just as I was expecting.

But now the result value of the second sample is always zero. I'm trying to read the value from " ADC_readResult(myAdc, ADC_ResultNumber_1) ". Am I still missing something?

I have associated the EOC1 to ADCINT2 as "ADC_setIntSrc(myAdc, ADC_IntNumber_2, ADC_IntSrc_EOC1);"

Is it correct?

Regards,

Mário

Based on the code you posted before, maybe this is the problem:

ADC_setSocChanNumber (myAdc, ADC_SocNumber_0, ADC_SocChanNumber_A0);
ADC_setSocChanNumber (myAdc, ADC_SocNumber_0, ADC_SocChanNumber_B0);

This configures SOC0 first for A0, then overwrites it to B0.  I think you want:

ADC_setSocChanNumber (myAdc, ADC_SocNumber_0, ADC_SocChanNumber_A0);
ADC_setSocChanNumber (myAdc, ADC_SocNumber_1, ADC_SocChanNumber_B0); 

You may also want to double check that the trigger and acquisition window for both SOC0 and SOC1 are correctly configured.

Yes, I do want to check the trigger of each sample and the acquisition window in the next step.

I do remember of changing the parameter that you've suggested, but the register on the debug mode ADCRESULT1 remain with the zero value.

While we're exchanging messages I've managed to perform some modifications in the code, now I have two ISR's functions for the two sample acquisitions.

The first one is doing good, I can check ADC_count value per second and the result value of the conversion.

The second isn't doing that good, I'm able to check the ADC_count2 value per second but the result ADCRESULT1 isn't changing.

The code of ADC initialization is as follows:

PIE_registerPieIntHandler(myPie, PIE_GroupNumber_10, PIE_SubGroupNumber_2, (intVec_t)&adc_isr2);

void adc_init()

{
// Initialize the ADC
ADC_enableBandGap(myAdc);
ADC_enableRefBuffers(myAdc);
ADC_powerUp(myAdc);
ADC_enable(myAdc);
ADC_setVoltRefSrc(myAdc, ADC_VoltageRefSrc_Int);

// Clear ADCINT1 flag reinitialize for next SOC
ADC_clearIntFlag(myAdc, ADC_IntNumber_1);
ADC_clearIntFlag(myAdc, ADC_IntNumber_2);
// Enable ADCINT1 in PIE
PIE_enableAdcInt(myPie, ADC_IntNumber_1);
PIE_enableAdcInt(myPie, ADC_IntNumber_2);
// Enable CPU Interrupt 1
CPU_enableInt(myCpu, CPU_IntNumber_10);
// Enable Global interrupt INTM
CPU_enableGlobalInts(myCpu);
// Enable Global real-time interrupt DBGM
CPU_enableDebugInt(myCpu);

//ADCINT1 trips after AdcResults latch
ADC_setIntPulseGenMode(myAdc, ADC_IntPulseGenMode_During);

//Enabled ADCINT1
ADC_enableInt(myAdc, ADC_IntNumber_1);
ADC_enableInt(myAdc, ADC_IntNumber_2);

//Disable ADCINT1 Continuous mode
ADC_setIntMode(myAdc, ADC_IntNumber_1, ADC_IntMode_ClearFlag);
ADC_setIntMode(myAdc, ADC_IntNumber_2, ADC_IntMode_ClearFlag);

//setup EOC1 to trigger ADCINT1 to fire
ADC_setIntSrc(myAdc, ADC_IntNumber_1, ADC_IntSrc_EOC0);
ADC_setIntSrc(myAdc, ADC_IntNumber_2, ADC_IntSrc_EOC1);

//set SOC0 channel select to ADCINA0
ADC_setSocChanNumber (myAdc, ADC_SocNumber_0, ADC_SocChanNumber_A0);
ADC_setSocChanNumber (myAdc, ADC_SocNumber_1, ADC_SocChanNumber_B0);

//set SOC0 start trigger on EPWM1A, due to round-robin SOC0 converts first then SOC1
ADC_setSocTrigSrc(myAdc, ADC_SocNumber_0, ADC_SocTrigSrc_EPWM1_ADCSOCA);
ADC_setSocTrigSrc(myAdc, ADC_SocNumber_1, ADC_SocTrigSrc_EPWM1_ADCSOCB);

//set SOC0 S/H Window to 7 ADC Clock Cycles, (6 ACQPS plus 1)
ADC_setSocSampleWindow(myAdc, ADC_SocNumber_0, ADC_SocSampleWindow_7_cycles);
ADC_setSocSampleWindow(myAdc, ADC_SocNumber_1, ADC_SocSampleWindow_7_cycles);

}

interrupt void adc_isr2(void)
{
ADC_count2++;

//discard ADCRESULT0 as part of the workaround to the 1st sample errata for rev0
// A0_res1 = ADC_readResult(myAdc, ADC_ResultNumber_0);
A0_res2 = ADC_readResult(myAdc, ADC_ResultNumber_1);

// ADC0 = (A0_res1+A0_res2) >> 1;
// ADC1 = (A1_res1+A1_res2) >> 1;

// Clear ADCINT1 flag reinitialize for next SOC
// ADC_clearIntFlag(myAdc, ADC_IntNumber_1);
ADC_clearIntFlag(myAdc, ADC_IntNumber_2);

// Acknowledge interrupt to PIE
PIE_clearInt(myPie, PIE_GroupNumber_10);

return;
}

Thanks a lot for your fast response.

Regards,

Mário

Devin, I just found the error of my code :)

I just changed this line:

ADC_setSocChanNumber (myAdc, ADC_SocNumber_1, ADC_SocChanNumber_B0);

by this one:

ADC_setSocChanNumber (myAdc, ADC_SocNumber_1, ADC_SocChanNumber_A1);

and now its working.

The result wasn't being stored where I was reading it.

Thanks.

Regards,

Mário