FRDM-KV31F boards shipped with MBED debug firmware

Document created by Philip Drake Employee on Sep 21, 2016Last modified by Adrian Puga Candelario on Jun 6, 2019
Version 4Show Document
  • View in full screen mode


It has come to my attention that a batch of FRDM-KV31F MCU boards, were shipped to people, programmed with MBED OpenSDA firmware.


The Kinetis Motor Suite GUI scripts load the reference project image into the KV31F MCU flash using the MSD programming built into the P&E Micro firmware. It specifically looks for the FRDM-KV31F MSD drive.  NXP moved away from the MBED firmware to eliminate the mass erase possibilities that could occur.


The FRDM-KV31F does not appear on these MBED boards. In fact, unless you have run the mbedWinSerial.exe installer found here, or get the latest driver here the mbed serial port will not enumerate. Plug in your FRDM-KV31F board and run the installer.  But let's not stop there. We want to make sure you don't mass erase your MCU and blow away the  KMS execute only library stored in the MCU's flash.


Let me give you a work around for now. Any MBED enabled FRDM board will still work with KMS, but you should use the Segger JLINK debug interface. It will not mass erase your KMS firmware like the MBED debug interface can.



The workaround uses the Segger Jlink OPENSDA 2.1 firmware.


The MBED OPENSDA driver can be replaced with the SEGGER jlink version of the debug tool. It does not have a drag and drop feature which is used by KMS, but that is not a bad thing.  The segger debug has a good serial interface and is supported by KDS and IAR. 


Steps for the workaround

  1. Put the MBED debug into bootloader mode
  2. Drag and drop the .bin of the Segger debug tool
  3. Power cycle board.
  4. Open KMS – create a new project
  5. When the image does not match and KMS wants to communicate or download a new image, decline.  We will do this manually with the IDE.
  6. If IAR – open the new project – compile the release versions of startup and platform.
  7. Open options for the FRDM target application and change debugger from PEMICRO to JLINK
  8. if KDS - do the same basic switch that we did with IAR – select the JLINK as the download and debug interface.
  9. Compile and download to the MCU.
  10. Run the program and exit from debug.
  11. If you are using KDS you will have to now have to hit the reset button on the FRDM-KV31F board.
  12. Go back to the KMS window and connect with the Press to Connect icon  and then verify this icon shows you connected Connected
  13. Execute KMS normally.
  14. If you use the Motion Sequence Build, note that hitting the TARGET will compile but the download script will fail. You will want to compile and download the project back in the IDE.

I hope this is a help.

I’ll be working on a way to get the PEMICRO OPENSDA binary onto the board for MSD drag and drop functionality.


Happy Motoring

Philip Drake

Systems Engineer