ADS7828: ADS7828 no response

Frank Xiao

Genius 12055 points

Part Number: ADS7828

Hi team,

My customer is using the ADS7828 in the PMBUS with FPGA, when reset the FPGA, the PMBUS will be locked(FPGA send signal, ADS7828 no response). We want to check whether the ADS7828 will cause the issue, if yes, interrupt read or write will cause it? Thanks

over 4 years ago

0 Cynthia over 4 years ago

TI__Mastermind 24970 points

Hello,

What do you mean y the FPGA is reset?

Is the power cycled on the FPGA? I would suggest probing the digital bus to the ADC when the FPGA is being reset to see what the ADC is being sent. please share this.

Any device on the bus could lock up if the digital bus depending on what the FPGA is outputting.

Regards

Cynthia

0 Frank Xiao over 4 years ago in reply to Cynthia

TI__Genius 12055 points

Hi Cynthia,

Thanks for your feedback. Currently we cannot capture the waveform(random happen). Based on your experience, whether the ADS7828 I2C has the possibility to pull the SCL or SDA low(stuck)? Thanks.

0 Frank Xiao over 4 years ago in reply to Frank Xiao

TI__Genius 12055 points

Hi Cynthia,

The waveform is as below, we can find the SDA is low. Thanks.

0 Frank Xiao over 4 years ago in reply to Frank Xiao

TI__Genius 12055 points

Hi Cynthia,

Do we have some update? Thanks.

0 Cynthia over 4 years ago in reply to Frank Xiao

TI__Mastermind 24970 points

Hello Frank,

The scope shot shows an issue with the communications.

The SDA line should be high once the communication is done, but there is no acknowledge at the end, there is only 8 SCK pulses instead of 9.

This could be locking up the bus.

This communication is from the FPGA when it is reset? There should be a way to either complete the communication, or have the FPGA not use the bus when it is being reset

Regards

Cynthia

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ADS7828: ADS7828 no response