how do i use a frdm-k22f to program an external k20?

[rodneysinclair]

I'm developing code for a K20 processor and would like to use my FRDM-K22F board to program it, however none of my attempts have been successful.

I cut the trace underneath J4 as described in the documentation and it appeared that the programmer was still talking to the on-board K22 rather than my external K20.  I removed the SWD_DIO pin on the K22 and now the programmer  doesn't work at all.

It it possible to use the FRDM-K22F to program an external K20?  If so, what have I missed?

[rodneysinclair]

I said "J4" when I meant "J7"

[Alice_Yang]

Hello Rondney,

When debug use the k20, it not only need connect the one pin,

there is much pins. If you still want use it , there is a reference , you can check .

https://mcuoneclipse.com/2015/04/21/proof-of-concept-open-source-arm-swd-debug-and-general-purpose-b...

https://mcuoneclipse.com/2015/05/17/tinyk20-open-source-arm-debuguniversal-board-first-prototypes/

BR

Alice

[rodneysinclair]

Alice,

Your comments are not addressing my question.

Rodney

[Alice_Yang]

Hi Rodney,

I know your meaning , you want to use the K20 on FRDM-K22 board as a debugger

to debug another K20 chip .

Yes, it is possible, while not only cut the J7(you need cut the two pin from the back of the board) then connect it to another K20 chip,

there still have other pins need to connect , you can check the SCH of frdm-k22.

BR

Alice

[Alice_Yang]

Hello Rondney,

Do you meaning program the K20 on FRDM-K22 board or other K20 ?

If the k20 on FRDM-K22 boar, you can directly use JTAG j12 on the board .

If the other K20,  how do you connect ? I think it is hard .

Hope it helps

Alice

[rodneysinclair]

Alice,

I said an external K20.  That means a K20 that isn't on the FRMD-K22F.

Rodney