AMC6821 SDA line stays low sometimes

Olan Way

Other Parts Discussed in Thread: AMC6821

Our AMC6821 SDA line stays low sometimes. We then have to toggle the SCLK line several times to make the chip release the SDA line, to allow it to go high again. Please suggest why this happens.

over 10 years ago

0 Mayrim Verdejo over 10 years ago

TI__Genius 15760 points

Hi Olan,

This question will be better supported on the PA Data Converters Forum.

Mayrim

0 Matthew Sauceda over 10 years ago

TI__Genius 11750 points

Howdy Olan,

Can you supply an oscilloscope capture of the issue, specifically during a full communication transaction?

Thanks,
Matt

0 Olan Way over 10 years ago in reply to Matthew Sauceda

Prodigy 190 points

Hi Matthew,

Unfortunately, we do not have an oscilloscope capture. We cannot easily reproduce the problem, where the SDA line gets stuck low. But it has happened several times.

Our I2C master does not attempt to send anything while this SDA line is low, so there is no activity on the SCLK in this state.

Olan

0 Matthew Sauceda over 10 years ago in reply to Olan Way

TI__Genius 11750 points

Howdy Olan,

Could you provide a capture of a working I2C communication transaction, this will allow me to verify and rule out anything from a timing violation perspective. In the meantime, I will dig for more information and update this post as I find new information that may be applicable towards the problem.

Thanks,
Matt

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AMC6821 SDA line stays low sometimes