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Original question:

BQ79600EVM: Wake up BQ79600 with help of SPI bus

BQ79600EVM: Try to WakeUP BQ79600EVM, from the SPI bus with +5V as power.

jiao yu
Prodigy 101 points
Part Number: BQ79600EVM
Other Parts Discussed in Thread: BQ79600-Q1

Try to WakeUP BQ79600EVM, from the SPI bus with +5V as power.

SPI_RDY is low. Wake up failed

  • 0
    TI__Intellectual 1760 points

    Hi Jiao,

    Can you give more information when you say "wake up failed", what behavior are you seeing?

    Please check that the following are set correctly on the EVM:

    1. J1 and J3 should be set to the 5V
    2. J10, J11 and J12 should be set to SPI
    3. R7 and R9 should be removed
    4. R8 and R10 should be populated with 0 ohm resistors

    Regards,

    Geoff

  • 0 in reply to Geoffrey Grimmer
    Prodigy 101 points
    1. J1 and J3 should be set to the 5V
    2. J10, J11 and J12 should be set to SPI
    3. R7 and R9 should be removed
    4. R8 and R10 should be populated with 0 ohm resistors

    These are all checked OK。

    Send Wake ping，and  Send a single device write to BQ79600-Q1 to set CONTROL1[SEND_WAKE]=1, which wakes up all stacked
    devices.     But There is no reply

  • 0 in reply to jiao yu
    TI__Intellectual 1760 points

    Hi Jiao,

    Please read the fault registers on the BQ79600 and see if any faults are set. Please send a list of any faults so that I can assist further.

    Thanks,

    Geoff

  • 0 in reply to Geoffrey Grimmer
    Prodigy 101 points

    Hi ！

    Unable to establish communication，So it can't be read。

    The MCU tried to contact 79600 by sending two commands to wake up the ping and SPI, but 79600 did not respond.The waveform of the attachment ，The top half is two wake-up pings And an SPI message，The bottom half is to magnify that message。CH4 is SPIRDY。

  • 0 in reply to jiao yu
    TI__Intellectual 1760 points

    Hi Jiao,

    From the image it appears that nCS is being driven high by the MCU during the command frame at the end of the bytes. From section 7.3.2.1.2.2 SPI of the datasheet:

    Please ensure that nCS is held low for the duration of the command frame and try again.

    Thanks,

    Geoff

  • 0 in reply to Geoffrey Grimmer
    Prodigy 101 points

    First of all, thank you very much for your reply

    The current phenomenon is that the 79616 device on the Daisy chain has shown a wake-up state，But there was still no data on the SPI's MISO data line,I Want to ask for Under what circumstances or under what command will SPI respond.thank you

  • 0 in reply to jiao yu
    TI__Intellectual 1760 points

    Hi Jiao,

    The 79616 device will only reply to read commands, not to writes. Before trying to read/write to stack devices please make sure that you follow section 7.3.2.3.1 of the BQ79600 datasheet to auto-address all devices. 

    Thanks,

    Geoff