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AM2432: Trouble doing uart flashing with jump-wired qspi flash

Hang Yang
Intellectual 2781 points
Part Number: AM2432

Hi BU experts，

My customer’s broad doesn’t have external flash, now they are jump wiring qspi flash to an ALV am2432 and try to do UART flashing. The first picture is where they get stuck. They’ve jump wired d0-3, clk and have cs pulled down. They use lp sbl here since it’s qspi. VDDSHV4 is powered by 3.3. Also they’ve walk through this process on EVM and LP.Any idea how to solve this problem?

Meanwhile, customer’s original design is to flash eMMC without qspi flash, is that possible?

Thanks,

Hang

  • 0
    TI__Expert 7630 points

    Hi Hang,

    What do you mean by having cs pulled down? did you wire the CS from the flash to the SoC? Does it work fine on EVM and Launchpad? 

    Best,

    Daniel

  • 0 in reply to Daniel Bermudez
    TI__Intellectual 2781 points

    Hi Daniel,

    As you can see from the picture, L19/L18 pin on AM243x is not connected, so they can't not wire cs to am243x. Meanwhile, they pull down the first pin of the flash, which is /cs on the left of the picture to ensure the flash is "selected". 

    Daniel Bermudez said:
    Does it work fine on EVM and Launchpad? 

    Since EVM and Launchpad have flash already, they didn't test this jump wiring on them. 

    As an update, they use the same jump wiring setup on the flash that they took from Launchpad board, and still have the same problem.

    Regards,

    Hang.

  • 0 in reply to Hang Yang
    TI__Expert 7630 points

    Hi Hang,

    The CS signal should not be held low constantly, this signal has to be connected to the SoC because it serves as a start of transaction signal to send the commands from the device in order to set up the flash. Tying this signal low might cause the SoC and flash to get out of sync. Additionally, some flash devices require this high-low low-high transitions to indicate start and end of transaction, which seems to be the case with the flash device used in our AM243x EVM: 

    I would suggest jump wire this signal as well and try again. Keep in mind that the communication with flash devices have to meet timing that I cannot guarantee will be met in a setup like this, if you keep running into issues even after tying the CS signal then please refer to the DS of flash you are using and compare the timing spec with your current observations in your scope. 

    Please give this a try and let me know if it fixes your issue

    Best,

    Daniel