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TMS320F28388D: The boot mode pin design.

Luke Chen
Expert 5090 points

Part Number: TMS320F28388D

Hi champs,

My customer adds pull-up resistors to GPIO72 and GPIO84 for boot mode select, we know during application run time GPIO72 is also used as ESC_TX1_DATA3 and GPIO84 is for ESC_TX0_ENA pins connecting to external PHY for EtherCAT function.

In my opinion, ESC_TX1_DATA3 and ESC_TX0_ENA are external PHY's input pins, so these two pins won't have any influence during the boot mode checking time when system power on. And when system boot from flash memory, CPU1 configures these two pins for EtherCAT and these two pins will work without problems.

Is it correct? Should we add external circuit to GPIO72 and GPIO84 separating boot time and application run time please?

Regards,

Luke

  • 0
    TI__Guru** 116101 points

    Hi Luke,

     

    In my opinion, ESC_TX1_DATA3 and ESC_TX0_ENA are external PHY's input pins, so these two pins won't have any influence during the boot mode checking time when system power on. And when system boot from flash memory, CPU1 configures these two pins for EtherCAT and these two pins will work without problems.

    Is it correct?

      Yes, this is correct. Since these are output from device, it is ok to use them as BOOTPIN.

    Regards,

    Vivek Singh