BQ78Z100: I2C Got Stuck

Kazuki Itoh

Genius 10780 points

Part Number: BQ78Z100

Hi team,

My customer observed I2C got stuck while communicating.

SCL is stuck to high and SDA is stuck to unstable (almost low).

TMS570 is the master and BQ78Z100 is the slave device.

I guess this is similar problem to this thread.

My customer observed the stuck was resolved by one power cycle of TMS570 and pull-up resistor power supply.

What do you think the root cause here?

Is power cycle supposed to be right approach to reset I2C?

Regards,

Itoh

0 Andy Liu (BMS) over 5 years ago

Hi Itoh,

If TMS570 just resets its i2c module, will the i2c communication also recover?

Andy

0 Kazuki Itoh over 5 years ago in reply to Andy Liu (BMS)

Hi Andy,

Yes.

Do you happen to know what the cause should be?

Is there any function BQ78Z100 has which may reset when I2C pull-up & master power off?

Regards,

Itoh

0 Kang Kang over 5 years ago in reply to Kazuki Itoh

Hello Itoh-san,

There is no reset for I2C engine for this part.

This seems to be more of a TMS chip issue than a bq78z100 gauge issue. Our gauge is not pulling the line low.

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