TMDSCNCD28379D: ADC RESULT REGISTER PROBLEM (NOT MATCHED TO SOC)

Eunjin

Part Number: TMDSCNCD28379D
Other Parts Discussed in Thread: C2000WARE

Tool/software:

I intend to use ADCA0~5 ADCB0~5 with SOC0 assigned to ADCA0, SOC1 to ADCA1,....and so on in sequential order.

The relevant code is set up as follows

void setupADC(void)
{

//single ended

AdcSetMode(ADC_ADCA, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);
AdcSetMode(ADC_ADCB, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);

EALLOW;
//ADCA
AdcaRegs.ADCCTL2.bit.PRESCALE = 0;

AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1; 

AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1; 

//ADCB
AdcbRegs.ADCCTL2.bit.PRESCALE = 0;

AdcbRegs.ADCCTL1.bit.INTPULSEPOS = 1; 

AdcbRegs.ADCCTL1.bit.ADCPWDNZ = 1; 

EDIS;

DELAY_US(1000);
}

void setupADCSOC(void)
{

    EALLOW;
//ADCA

   AdcaRegs.ADCSOC0CTL.bit.CHSEL = 0;     // SOC0(=ADCA0)
   AdcaRegs.ADCSOC0CTL.bit.ACQPS = 50;    
   AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0


   AdcaRegs.ADCSOC1CTL.bit.CHSEL = 1;     // SOC1(=ADCA1)
   AdcaRegs.ADCSOC1CTL.bit.ACQPS = 50;     
   AdcaRegs.ADCSOC1CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0
//
   AdcaRegs.ADCSOC2CTL.bit.CHSEL = 2;     // SOC2(=ADCA2)
   AdcaRegs.ADCSOC2CTL.bit.ACQPS = 50;     
   AdcaRegs.ADCSOC2CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcaRegs.ADCSOC3CTL.bit.CHSEL = 3;     // SOC3(=ADCA3)
   AdcaRegs.ADCSOC3CTL.bit.ACQPS = 50;     
   AdcaRegs.ADCSOC3CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0


   AdcaRegs.ADCSOC4CTL.bit.CHSEL = 4;     // SOC4(=ADCA4)
   AdcaRegs.ADCSOC4CTL.bit.ACQPS = 50;    
   AdcaRegs.ADCSOC4CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0


   AdcaRegs.ADCSOC5CTL.bit.CHSEL = 5;     // SOC5(=ADCA5)
   AdcaRegs.ADCSOC5CTL.bit.ACQPS = 50;    
   AdcaRegs.ADCSOC5CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

//   AdcaRegs.ADCINTSEL1N2.bit.INT1SEL = 0; // End of SOC5 will set INT1 flag
//   AdcaRegs.ADCINTSEL1N2.bit.INT1E = 1; // Enable INT1 flag
//   AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; // Make sure INT1 flag is cleared

   //ADCB

   AdcbRegs.ADCSOC0CTL.bit.CHSEL = 0;  // SOC0(=ADCB0)
   AdcbRegs.ADCSOC0CTL.bit.ACQPS = 50;     
   AdcbRegs.ADCSOC0CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcbRegs.ADCSOC1CTL.bit.CHSEL = 1;     //  SOC1(=ADCB1)
   AdcbRegs.ADCSOC1CTL.bit.ACQPS = 50;     
   AdcbRegs.ADCSOC1CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcbRegs.ADCSOC2CTL.bit.CHSEL = 2;     //  SOC2(=ADCB2)
   AdcbRegs.ADCSOC2CTL.bit.ACQPS = 50;     
   AdcbRegs.ADCSOC2CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcbRegs.ADCSOC3CTL.bit.CHSEL = 3;     //  SOC3(=ADCB3)
   AdcbRegs.ADCSOC3CTL.bit.ACQPS = 50;     
   AdcbRegs.ADCSOC3CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcbRegs.ADCSOC4CTL.bit.CHSEL = 4;     //  SOC4(=ADCB4)
   AdcbRegs.ADCSOC4CTL.bit.ACQPS = 50;     
   AdcbRegs.ADCSOC4CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

   AdcbRegs.ADCSOC5CTL.bit.CHSEL = 5;     //  SOC5(=ADCB5)
   AdcbRegs.ADCSOC5CTL.bit.ACQPS = 50;    
   AdcbRegs.ADCSOC5CTL.bit.TRIGSEL = 1;   // Trigger on CPUTIMER0

  // AdcbRegs.ADCINTSEL1N2.bit.INT1SEL = 5; // End of SOC5 will set INT1 flag
   //AdcbRegs.ADCINTSEL1N2.bit.INT1E = 1; // Enable INT1 flag
  // AdcbRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; // Make sure INT1 flag is cleared


   EDIS;
}

As intended, when 3.3V is applied to the ADCA0 pin, the RESULT0 register should output 4095, and when 0V is applied to the ADCA0 pin, result 0 should result in 0.

However, applying 3.3V to ADCA0 changes the values in the RESULT1 and RESULT2 registers (In this case, pins ADCA1 through ADCA5 are connected to GND.)

Additionally, when 3.3V is applied to ADCA1 (with ADCA1 and ADCA 2 through 5 are connected to GND), there is no change in the values of the RESULT1 register.

I have correctly assigned the pins, set the SW2 : reference voltage to 0–3.3V, but I am still experiencing unintended changes in the RESULT register values & same problem in ADCB.

ADCA0 3.3V, ADCA1~5:0V

--> ADCA0 : 0V

RESULT1,2 -->0

and adcA1 3.3V(YELLOW LINE) --> ALL RESULT 0

11 months ago

0 Eunjin 11 months ago

Prodigy 40 points

ADCA1 is connected to 3.3V, while ADC0 and pins 2 through 5 are connected to GND.

0 Susmitha Bumadi 11 months ago in reply to Eunjin

TI__Expert 3350 points

Eunjin said:
As intended, when 3.3V is applied to the ADCA0 pin, the RESULT0 register should output 4095, and when 0V is applied to the ADCA0 pin, result 0 should result in 0.

Yes, that's right.

After the ADC completes a conversion of SOC1, the result is placed in the ADCResult register 1.

SOC2 conversion result is placed in result register 2. and so on.

There are similar examples for ADC in C2000ware.Can you please try them first?

Here is the link to it.

[install path] \C2000Ware_5_03_00_00\driverlib\f2837xd\examples\cpu1\adc\

Thanks,
Susmitha

0 Eunjin 11 months ago in reply to Susmitha Bumadi

Prodigy 40 points

Hello, thank you for your response. However, I already understand ADC and SOC conversion. My current issue is that applying voltage to the ADC0 pin causes the RESULT1 and RESULT2 values to change.

Thanks,

Regard eunjin

0 Susmitha Bumadi 11 months ago in reply to Eunjin

TI__Expert 3350 points

Hi Eunjin,

Did you happen to take a look at the examples and try to run some?

What's the SYSclk and adcclk values you are using in this example?

Thanks,

Susmitha

0 Eunjin 11 months ago in reply to Susmitha Bumadi

Prodigy 40 points

In my code, the sysclk is set to 100 MHz, and the ADC is set to 51 sysclk.

ConfigCpuTimer(&CpuTimer0, 100, 10);

AdcaRegs.ADCSOC0CTL.bit.CHSEL = 0; // SOC0(=ADCA0)
AdcaRegs.ADCSOC0CTL.bit.ACQPS = 50; // Sample window is 50+1 SYSCLK cycles
AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 1; // Trigger on CPUTIMER0

0 Eunjin 11 months ago in reply to Susmitha Bumadi

Prodigy 40 points

also, I ran the example(adc_soc_software_sync_cpu01.c) file you mentioned, and it works fine, and the ADC result also comes out correctly.

However, when compared to my code, the only difference seems to be the use of the input XBAR, and there don't appear to be any other differences in the ADC configuration.

0 Susmitha Bumadi 11 months ago in reply to Eunjin

TI__Expert 3350 points

Hi Eunjin,

I see you have set AdcaRegs.ADCCTL2.bit.PRESCALE = 0; that means prescale ratio is 1, which divides SYSCLK by 1, that gives ADCCLK 100MHZ in this case assuming SYSCLK is 100MHZ.

If you want ADCCLK to be 50MHZ..please set AdcaRegs.ADCCTL2.bit.PRESCALE = 2.

Can you try changing above and see if your code works?

Thanks,

Susmitha.

0 Eunjin 11 months ago in reply to Susmitha Bumadi

Prodigy 40 points

HI,

Sorry, I misspoke earlier. It is correct to set the prescale to 0. I am using Timer 0 to trigger the ADCSOC every 10 µs and read the voltage values of the pins I using ADCSOC and interrupt occurs when the EOC occurs

Thanks,

eunjin

0 Susmitha Bumadi 11 months ago in reply to Eunjin

TI__Expert 3350 points

Hi Eunjin,

I am closing this thread, as this is duplicate thread.

There is other thread similar to this, please track support here:

TMDSCNCD28379D: ADC RESULT REGISTER PROBLEM (NOT MATCHED TO SOC) - C2000 microcontrollers forum - C2000︎ microcontrollers - TI E2E support forums

Thanks,

Susmitha

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TMDSCNCD28379D: ADC RESULT REGISTER PROBLEM (NOT MATCHED TO SOC)