TMS570LS3137: How to configure the internal ADC for periodic sampling without software intervention?

John11513

Part Number: TMS570LS3137

Hi team,

This is a question from my customer Could you please help me with it?

They want to configure the ADC to sample external signal continuously with 10ksps of sample rate. They have tried to trig ADC with RTI compare 0 interrupt, however they found the ADC cannot be triggered periodically unless the interrupt flag is cleared in interrupt service routine, this is not their expecting. Could you please give me some proposal on how to configure the ADC to implement periodic sampling without software intervention?

Thank you,

John

over 7 years ago

0 John11513 over 7 years ago

TI__Expert 5720 points

Hi Team,
Could anyone help me with this simple question?
Thank you,
John

0 QJ Wang over 7 years ago in reply to John11513

TI__Guru**** 196776 points

Hello John,

The RTI interrupt flag has to be cleared in order to get next RTI interrupt and next ADC sample.

rtiREG1->INTFLAG = 2U; //compare 1

0 John11513 over 7 years ago in reply to QJ Wang

TI__Expert 5720 points

Hi,

Thank you for reply. However that is what we have known. My question is how to implement periodic sampling without software intervention?

Thank you and best regards,

John

0 Sunil Oak over 7 years ago in reply to John11513

TI__Mastermind 49120 points

Hi John,

The RTI also support an auto-clear function for the compare flags, which was designed specifically for this purpose. The auto-clear for each compare flag can be enabled via the RTIINTCLRENABLE register, described on page 460 of SPNU499.

The timing of the auto-clear can be configured via the RTICMPxCLR register (x = 0, 1, 2 or 3). You can configure this along with the auto-update register to periodically set and clear the desired compare flag without having to generate an actual interrupt to the CPU.

Regards,
Sunil

0 NeilBerry_at_Parker over 7 years ago

Expert 1995 points

You could create a task with the desired update rate, and call the adcGetData function. This might require setting the software trigger option.

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TMS570LS3137: How to configure the internal ADC for periodic sampling without software intervention?