TMS320F280039C: XF280039CSPM

William Szatkiewicz

Part Number: TMS320F280039C
Other Parts Discussed in Thread: TMS320F28069M

Hi,

I am finding that after I program either the TDI (GPIO35) or TDO (GPIO37) as a general purpose output I can then no longer connect to the JTAG emulator again when my target board is setup to boot from flash. This prevents me from being able to repurpose the TDI or TDO pins. Has this issue been resolved? What can I do to be able to use the TDI and TDO pins as general purpose outputs but afterwards be able to connect to the target device and load another program?

Please advise and let me know if you need any more information.

Thank you,

William Szatkiewicz

over 2 years ago

0 Kevin Allen18 over 2 years ago

TI__Mastermind 45606 points

Hi William,

Are you trying to re-connect using 2-pin CJTAG? You would have to use this mode if TDI / TDO are used for other purposes.

Best,

Kevin

0 William Szatkiewicz over 2 years ago in reply to Kevin Allen18

Prodigy 120 points

Hi Kevin,

I was trying to connect using standard JTAG. I have used TDI / TDO as GPIO on other C2000 processors (TMS320F28069M) and then was able to connect using the JTAG interface and reprogram if needed. That has changed for this processor and is no longer an option?

Please confirm.

Thank you,

William

0 Benjamin Collier over 2 years ago in reply to William Szatkiewicz

TI__Mastermind 36526 points

William,

Could you please try booting your device in wait boot mode?

You're correct that you will have an issue with this if you are booting to flash. You could also use cJTAG as Kevin mentioned.

Best Regards,

Ben Collier

+1 William Szatkiewicz over 2 years ago in reply to Benjamin Collier

Prodigy 120 points

Hi Ben, I can boot the device in wait boot mode, but the issues is that requires a PCB hardware change and is not practical for my application. I mainly wanted to confirm this issue when booting to flash and that there is no solution. Please confirm.

Thank you,
William

0 Benjamin Collier over 2 years ago in reply to William Szatkiewicz

TI__Mastermind 36526 points

Hi William,

This issue is expected for 4-pin JTAG.

As Kevin mentioned, you should be able to connect using cJTAG. If your board supports 4-pin JTAG then it should already support cJTAG since cJTAG uses a subset of pins from 4-pin JTAG.

If you have an XDS110 or XDS200, this should be easy to try. You will just need to edit your target configuration file. Please let me know if you need some help to do this.

Best Regards,

Ben Collier

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280039C: XF280039CSPM