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TMS320F28035

Viktorija Cecil
Mastermind 18501 points

Other Parts Discussed in Thread: TMS320F28035

Does TMS320F28035PN require external pull up resistors on the GPIO34 & GPIO37 pins in order for it to boot to flash?  If so, is there a way to enable the internal pull ups on these pins before jumping to flash?

Thanks

Viktorija

 

  • 0
    TI__Expert 8500 points

    Viktorija,

    According to the datasheet:

    "All GPIO pins are I/O/Z and have an internal pullup, which can be selectively enabled/disabled on a per-pin basis. This feature only applies to the GPIO pins. The pullups on the PWM pins are not enabled at reset. The pullups on other GPIO pins are enabled upon reset."

    When GPIO34/37 are both high the boot mode is defined by the GetMode function (programmed into the OTP by the customer). So, the strict answer is no, the user should not need external pullups on these pins to boot to flash. The one caveat is that the internal pulls are fairly weak to allow customers to overdrive. It is possible in a high noise environment that external resistors would be needed to keep the pins at '1'. Likely not though, most applications will not be high noise during the boot/initialization phase.

    Regards,
    Dave Foley

     

     

     

  • 0 in reply to David Foley
    Intellectual 370 points

    David:

    I think you are a  senior hardware engineers ,so please see  tags of  TMS320F28035 RESET" .

    Best Regards

    dowsheng.