AnsweredAssumed Answered

What's the minimum circuit requirement for KL/K mcu programming?

Question asked by Kai Liu on Feb 18, 2014
Latest reply on Sep 24, 2014 by Kai Liu

I am trying my best to use FRDM on board OpenSDA debugger to program hex/srec/bin code into off-board KL25Z/K20 boards.


I got the following errors:

  • Keil + CMSIS-DAP firmware, SWD/JTAG communication error
  • IAR + PEmicro OpenSDA firmware, a setup window popup to show no target MCU found.
  • Coocox + CoLinkEX + CoFlash, "Flash not blank !!! -> Can NOT Stop MCU !!!"


SWD should be the simplest way to program a cortex micro.  (VCC/GND, DIO/CLK/RST) I have double checked the connections. They are good.


But I have changed a TXC 8MHz crystal in these boards. I want to know if the crystal can influence the SWD programming? Is it possible to program a bare KL25Z chip (only MCU mounted on board, not crystal, only SWD connections are available, and power source comes from SWD as well) ?


So far I don't think cystal issue is the root cause of programming failure, because KL25Z can run from IRC. FSL can not enforce customer to add crystal for programming.


It is surprise to me when I failed in programming KL25Z with FRDM+CMSIS-DAP. This CMSIS-DAP programming configuration is even working well for other MCU.