BQ76952: I2C issue

Hello Ryker,

Can you share with me the procedure/test you are doing right before I2C is ‘locked’?

Also, when you say I2C is ‘locked’, are you seeing when you are trying to communicate with the AFE through I2C, there is no response or there is a response, but the command is not going through/there is a NACK?

A logic analyzer file may also be useful to show what is occurring.

Best Regards,
Alexis

Hi Alexis,

Please refer to below input and help to analyze. Thanks.

• There is a chance that the I2C will be locked by pausing randomly while the procedure is simulating. R&D guesses it is because the communication procedure between MCU and AFE is interrupted, which leads to MCU doesn't receive the stop signal.
• There is no response when R&D is trying to communicate with the AFE through I2C after I2C is 'locked'. What is recognized on the MCU is that the IIC bus is 'busy'.
• Customer hasn't logic analyze, so they can't provide relevant file.

Best Regards,

Ryker

Hello Ryker,

Thank you for sharing those details. Since the customer doesn’t have a logic analyzer, is it possible for them to share waveforms at the I2C lines?

You mentioned when the I2C is locked and can’t be unlocked by resetting bq76952. Did you also try with a partial reset?

A partial reset can be performed by pulling RST_SHUT high for less than 1 second. It is furthered explained in this FAQ: How do I RESET the BQ769x2 Device?

Also, have they tried generating the 8+1 clock signals to attempt to release the bus as well?

Best Regards,
Alexis