BQ27Z561: Stop bits in dffs

Michael Balourdas

Part Number: BQ27Z561

Hi team,

My customer has an MCU that automatically inserts stop bits. Should they send the DFFS as a continuous block or separate commands with the stop bits in between? Will the stop bits cause an issue in the device?

Thanks,

Michael

over 5 years ago

0 Kang Kang over 5 years ago

TI__Mastermind 24870 points

Hello Michael,

We have a gauge communications app note. Please refer to that.

There is also a flashstream app note on ti.com, please refer to that for programming.

0 Michael Balourdas over 5 years ago in reply to Kang Kang

TI__Expert 5455 points

Hi Kang,

My customer and I both reviewed the app notes and unfortunately were not able to determine an answer to the question. We didn't see any info about stop bits in either document.

Are they going to be an issue/are they needed in the BQ27Z561?

Thanks,

Michael

0 Kang Kang over 5 years ago in reply to Michael Balourdas

TI__Mastermind 24870 points

Hello Michael,

Stop bit is part of the I2C engine. Can the customer first study the waveforms and I2C traffic using an aardvark or beagle to sniff the traffic?

The flashstream app note is more on the .fs file format programming, which they will need.

0 Michael Balourdas over 5 years ago in reply to Kang Kang

TI__Expert 5455 points

Hi Kang,

So the flash stream files contain instructions for I2C operations required for updating a device’s instruction flash (IF) or data flash (DF). I understand that part.

And typically with I2C, a stop condition is sent after every command. So my assumption is that the stop condition should be sent at the end of each line of the bq.fs.

For example:

W: AA 3E 02 00 [Stop]

Is that correct?

Thanks,

Michael

0 Kang Kang over 5 years ago in reply to Michael Balourdas

TI__Mastermind 24870 points

Hello Michael,

Yes, that should be fine. I don't think we explicitly call this out. It is part of the I2C spec.

https://i2c.info/i2c-bus-specification

Thanks

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BQ27Z561: Stop bits in dffs