• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 347 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ76940: communication error with MCU

Junyeong Kim
Prodigy 10 points
Part Number: BQ76940

Hello, I'm developing BMS system.

MCU is RL78.

Yesterday the cell's voltage(which was read from MCU) wasn't changed although they were charged.

I think there was communication error between MCU and ASIC.

So my question is how can I know there is error between MCU and ASIC?

Is there any register about Comm error in BQ769xy?

I can't find in datasheet.

Thank you.

  • 0
    TI__Guru 54715 points

    Hi Junyeong,

    The BQ76940 does not have a communication status register.  The SYS_STATUS register indicates known faults.  

    If the device does not communicate the host should see a NACK.

    If the device has an XREADY fault set the voltages may not change even though the ADC is enabled.

    If the ADC_EN bit is cleared in the SYS_CTRL1 register the voltages will not change.

    To see if you have control of the device you might change a bit and read back its setting.  Select a bit which does not alter the behavior of the device operation in the mode you are using.  You might change TEMP_SEL to see that it changed.  Note that temperature readings are infrequent but you could get the other reading.  You might change one of the SHUT bits and set it back without completing the sequence.  You might alter the UV threshold momentarily by 1 count to see that it changes.  Other bits may be changed depending on your operating mode, select something suitable.