• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 83 subscribers
  • Views 378 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F2802X boot pins

Russ16615
Prodigy 20 points
Other Parts Discussed in Thread: TMS320F28023

I will be using a custum bootloader on a 38 pin TMS320F28023 and I'm running short on available pins.

Pins 34 and 37 are used by the ROM bootloader to select the boot mode. Is it possible to bypass/disable this so it will not use pin 34 (I would like to use this pin for GPIO and it is low on reset)?

I suspect it is not possible, but I wanted to confirm this.

Thanks in advance.

  • 0
    Intellectual 295 points
    I think it is impossible to disable bootloader pin checking on reset, May be some additional info can be found in "Custom bootloader options via OTP memory" pdf, but I am not sure about this..... Also You can use external components to handle this(i.e. set correct combination on reset and than multiplex pins back to board using external multiplexor and reset signal as a switch). If pin GPIO function is OUTPUT and initial state of pin is LOW - than You can INVERT the signal and use pullup resistor to set correct(HIGH) level during bootloader execution, when pin is configured as INPUT. Yes, why not, You can invert signal not only in case of output function of the pin. :)
  • 0
    Genius 5170 points

    I also don't believe boot loading pins can be avoided - if you need custom boot loading then search for an application note describing how to implement custom bootloading using OTP.

  • 0
    Intellectual 260 points

    Use port expander for ex. on I2C or SPI is you are running out of port pins.