Other Parts Discussed in Thread: BQ25731,
We are having an issue on the I2c bus when the PD chip communicates with the charger chip (BQ25731). The clock line is stretching when we switch/request a different voltage level using an external PD SINK device.
We have our own custom board based on the EVM.
The above is tested with the GUI-generated firmware using the TI tool for firmware customization.
This is the configuration file:
{"questionnaire":{"version":"7.0.4.6","answers":[0,3,3,0,1,2,1,null,1,null,2,12.6,1.536,null,null],"options":{},"configID":"0000","vendorID":"0000"},"configuration":{"data":{"selected_ace":[{"register":6,"data":[0,0,0,0,0,0,0,0]},{"register":22,"data":[10,48,48,77,0,0,0,0,0,0,7]},{"register":50,"data":[4,168,42,44,145,1,38,44,209,2,0,44,177,4,0,44,65,6,0,0,0,0,0,0,0,0,0,0,0,0,0]},{"register":51,"data":[4,44,145,1,16,44,209,2,0,44,177,4,0,44,65,6,0,69,65,6,0,0,0,0,0,0,0,0,0]},{"register":92,"data":[240,0,0,0,0,0,0,0,0,16,0,0,192,0,0,0,48,0,0,0,0,0,0,0,192,12,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,73,75,0,0,0,0,0]}]}}}
We've probed the line to monitor the data traffic and here is what we got:
the above sets the charge chip otg voltage to 20v, this is set correctly but no further I2c communication between the two chips "clk line is held LOW" .
In debugging, we have used the 4CC commands 'I2Cw' and 'I2Cr' to read/write to the charger chip from the PD chip which worked fine without any issues (writing the same sequence of data we probed from the line but with different/more delays) we don't see the issue when the commination is driven by the gui-generated firmware.
Could you please advise.
