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Original question:

TMS320F280039C: Occasional abnormal issues with chip power on

TMS320F28388S: TMS320F28388S: Occasional abnormal issues with chip power on

Yu Bao
Prodigy 50 points
Part Number: TMS320F28388S

There are 10PCS Board,only 1PCS abnormal.

When the chip is powered on, there may be occasional situations where the program does not boot in (especially when the board is left standing for a period of time), and it can still function normally after being powered on again. I'm not sure what the problem is. 

When it abnormal, test power/RST/XTAL all are right.

Is there any way to analysis 

  • 0
    Prodigy 50 points

    There are 2PCS DSP every PCBA. Abnormal DSP also occasional 

  • 0 in reply to Yu Bao
    TI__Mastermind 42195 points

    Yu,

    This sounds like a sequencing issue which is occurring after the device has been off for a while. Perhaps there is a capacitor charging which takes longer to charge after a long rest.

    When you say 

    Yu Bao said:
    test power/RST/XTAL all are right

    are you just verifying the steady state values, or did you observe this transition during power up? Please see the datasheet for the correct order and timings.

    Regards,
    Cody 

  • 0 in reply to Cody Watkins
    Prodigy 50 points

    Thanks Watkins

            It seems something wrong with BOOT MODE PINS. In the PIC, Yellow is 3.3V, Blue is 1.2V, Green is BOOT0, the rest is BOOT1.

           BOOT0 and BOOT1 have a 4.7kΩ pullup， but when the power on, BOOT0's Voltage is abnormal.

           

           

  • 0 in reply to Yu Bao
    TI__Mastermind 42195 points

    Yu,

    the device should only be sampling the bootmode pins, it should not be driving them during boot. Is there something else attached to the boot pin?

    A 4.7k ohm pull-up resistor should work well.

    Regards,
    Cody