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.

28075 boot-mode pins

Other Parts Discussed in Thread: TMS320F28069

Hi,

We are working with the TMX320F28075PZPT.   It appears from the datasheet and from putting a scope on the board we have that the boot-mode pins (GPIO 72 and GPIO 84 by default) are not internally pulled high, as is done with other C2000 variants.  Is this by design and intentional or is this an issue with the "X" parts that will be addressed when the TMS parts are released?

The TMS320F28069 that I have worked with has internal pull-ups on the boot-mode pins and states in the datasheet that external pull-ups are only required in noisy environments.

Also, if we want to change the boot-mode pins, per table 3-4 on page 494 of the TRM. Rows 3 and 4 are inconsistent in the GPIO to value numbering. The first 2 lines imply that the GPIO # and value are different by 1. The last line implies the register value is the same as the GPIO value.

Thanks,

Dave

  • Hi Dave,

      Is this by design and intentional or is this an issue with the "X" parts that will be addressed when the TMS parts are released?

    On this device PULLs are disable by default (on reset) where as on earlier device PULLs were enable. That's why you are seeing this difference. User need to have external PULLs on these pins for correct BOOT operation.

    Also, if we want to change the boot-mode pins, per table 3-4 on page 494 of the TRM. Rows 3 and 4 are inconsistent in the GPIO to value numbering. The first 2 lines imply that the GPIO # and value are different by 1. The last line implies the register value is the same as the GPIO value.

    Yes, there is an issue in document which we will be fixed in next revision. As stated in first 2 lines, GPIO # and value are different by 1.

    Regards,

    Vivek Singh

  • Hi Dave,

    Let us know if you have any further queries on this.

    Regards,

    Vivek Singh

  • Vivek , sorry for the late response, yes that answered my question, thanks...