TMS320F2812: UART not functional on power up.

May

Part Number: TMS320F2812

Posting in behalf of customer (cannot post in E2E, due system error)

"We have a TMS320F2812 application that is exhibiting a problem with the UART when running standalone. Upon power up, the activity indicator LED blinks telling us that the software is executing and timer interrupts are occurring properly. In about 30% of the power turn on events the UART does not function, the DSP does not respond to serial communications. Asserting the reset pin without power cycling brings the UART back into operation. What is causing this issue and how do we get around it? "

Thank you in advance.

Regards,
Maynard

over 4 years ago

0 Marlyn Rosales Castaneda20 over 4 years ago

TI__Mastermind 25800 points

Hi Maynard,

What clock source is being used for this application? Would it be possible to measure the baud rate and check how accurate it is in comparison to the expected? Also, are any error flags set when this happens?

Best Regards,

Marlyn

0 John Smith over 4 years ago in reply to Marlyn Rosales Castaneda20

Prodigy 20 points

SIT8924BM-83-18E-30.000000X

The problem occurs when the device is initially powered up. If it comes up running it will run all day thereafter.

0 Marlyn Rosales Castaneda20 over 4 years ago in reply to John Smith

TI__Mastermind 25800 points

Thank you John,

It would still help to have an answer to the following questions: Would it be possible to measure the baud rate and check how accurate it is in comparison to the expected? Also, are any error flags set when this happens (SCIRXST register)?

May said:
Asserting the reset pin without power cycling brings the UART back into operation

Does it work if you do a software reset (SWRESET bit of the SCICTL1 register)?

Best Regards,

Marlyn

0 John Smith over 4 years ago in reply to Marlyn Rosales Castaneda20

Prodigy 20 points

You can close this case. We found the problem.

0 Marlyn Rosales Castaneda20 over 4 years ago in reply to John Smith

TI__Mastermind 25800 points

Hi John,

If you don't mind sharing, what was the problem and solution? It could help others in the future.

Best Regards,

Marlyn

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TMS320F2812: UART not functional on power up.