How to use external J-Link Plus with TWRK64F?

[matthias2]

I've plugged in the J-Link ARM Cortex-M cable into J5 - K64 JTAG, but the JLink's LED stays Orange, which indicates RESET is asserted, and it cannot access it.

The Getting Started Guide does not indicate any additional steps to configure the board for this.

How can I use an external JTAG with the TWRK64F?

(I've used the J-Link OpenSDA for a while which worked fine, but now it seems to got 'locked' while I was playing with blinky example and I figured I'd try the unlock with the real J-Link).

Thanks!

  Matthias

[matthias2]

Thank for this simple answer. For others that end up here as well, here's the crucial information from the referenced blog post:

"Note that using the JTAG debug port (e.g. with Segger GDB server), the jumper J39 *has to be removed*! If the jumper is on, then the Segger GDB server silently quits (crashes?). Actually it shows an error message, then closes."

So, for external JTAG, remove J39.

I've went through the list of jumpers, but missed that one.

It would be helpful, if Jumper J39 could be mentioned in the TWR-K64F120M Tower Module User’s Guide, e.g. at 6.8.

[BlackNight · Accepted solution]

Hi Matthias,

see First Steps with the Freescale TWR-K64F120M | MCU on Eclipse 

I hope this helps,

Erich