TM4C123GH6PM: Problem with flashing

Hello Roelof,

It is not clear from your post how you are trying to connect to the MCU. What debug interface are you using? For LM Flash to erase flash memory, it would need to be through a supported interface which would be using a TM4C development kit and following the guidelines in: https://www.ti.com/lit/pdf/spma075

If you want to use another JTAG probe like one of the various XDS probes, then you can use CCS Uniflash instead.

i connect it with usb serial uart connection.

ok i will try via jtag. i buy a jtag probe and will try it this week.

I have now mounted the jtag but I have no reset buton this PCB how should I use the reset.

Hello Roelof,

The JTAG connection should include a connection to Reset and the JTAG should be able to reset the device as part of the programming process.

Since the JTAG connection should have a Reset signal routed to it, you could use that to trigger the reset manually as well.

Hello Ralph

I try but I get an error failed to unlock connected device. I know this is a modified board does this work differently or do I do something wrong.

Roelof

Hello Roelof,

Can you just try to erase Flash memory?

If you did brick the device, then yes you would need a reset button to help restore that, but I also think the Uniflash Debug Unlock doesn't work well. Let me know if Flash erase works and if not I will see if I can find the post about how to Debug Port Unlock with a JTAG probe. 

Hallo Ralph

I am trying to erase the flash memory but get the error unable to find target message

Hello Ralph

This also fails. don't have a reset button on the board. the jtag stick does have a reset pin but it doesn't seem to work with this either. either the jtag does not connect or something else is going on. I now request a new controller because my pellet boiler has to work quickly again. keep this as a hobby project to get it done again. Thanks for your help, please come back to this print again.

Roelof

Hello Roelof,

Alright. In the future do try and design these PCBs with a reset button so you can recover them with JTAG. The JTAG Reset pin is used as part of the process but you have to manually hold reset down while the unlock process goes on which is where the need for the button comes into play.