PMBus- UCD9222 FUSION I2C Script - Receives NACK for command after STORE_DEFAULT_ALL

Pawan Ghotikar

Hi TI,

I am running an I2C script using I2C driver on FPGA. I am receiving NACK for SOFT_RESET which is immediately after STORE_DEFAULT_ALL. I do pause for approx 2.2 seconds after STORE_DEFAULT_ALL and then send SOFT_RESET. But SOFT_RESET receives NACK.

-Pawan Ghotikar

over 9 years ago

0 Zhiyuan Hu over 9 years ago

TI__Genius 9845 points

It should work. 2.2 sec should be enough. Did you try disable the PEC? Did you try waiting for longer period? You may want to capture I2C waveform on scope and see what happened.

0 Pawan Ghotikar over 9 years ago in reply to Zhiyuan Hu

Expert 1140 points

Hi Zhiyuan Hu,
How to disable PEC?

-Pawan

0 Zhiyuan Hu over 9 years ago in reply to Pawan Ghotikar

TI__Genius 9845 points

To not send the PEC.

0 Pawan Ghotikar over 9 years ago in reply to Zhiyuan Hu

Expert 1140 points

I tried but doesn't work. I still get NACK. During the pause interval I am leaving I2C SCL and SDA hiz. Is it correct or do I have to hold SCL low?

Thanks,
Pawan Ghotikar

0 Zhiyuan Hu over 9 years ago in reply to Pawan Ghotikar

TI__Genius 9845 points

The recipe described in document should work. This is how Fusion GUI works. I suggest debug on your end.

In Fusion GUI, you can enable PMBus Logging feature under Tools. It will save all the communication between GUI and device in a log file. You can use the log as a reference to assist debugging.

Regards,
Zhiyuan

Power management

Power management forum

PMBus- UCD9222 FUSION I2C Script - Receives NACK for command after STORE_DEFAULT_ALL