Using FRDM-KL05 board as external debugger

[pgo]

Hi All,

I've used the other FRDM boards as external debuggers using USBDM but I have found what I believe is an error on the FRDMKL05 board.

On the other FRDM boards there is a normally-closed jumper that isolates the SWCLK signal between the on-board chip and the 10-pin SWD connector while leaving the SWCLK connected between the K20 debugger chip and the 10-pin SWD connector.  This allows the connection of an external target for debugging.

The corresponding jumper on the FRDL-KL05 completely isolates the 10-pin connector and I cannot see an purpose for this.

Is there something I'm missing?

Is this likely to be changed in future revisions?

The jumper in question is J6 on the FRDM-KL05 schematic:

http://cache.freescale.com/files/soft_dev_tools/hardware_tools/schematics/FRDM-KL05Z_SCH.pdf?fpsp=1

bye

[BlackNight · Accepted solution]

Hi pgo,

yes, this is a known bug.

See Debug External Processors with USBDM and Freedom Board | MCU on Eclipse which has the hardware fix for it described.

I have reported this schematic error to Freescale, and the wanted to have it fixed in a next board revision. I have not seen such a new board revision yet. Until then, the above workaround needs to be applied.

I hope this helps.

[pgo]

Thanks Erich

bye