Kevin Luty

Clock synchronization issue with KBOOT bootloader and MCG mode switching with FRDM-K22F

Discussion created by Kevin Luty on Apr 29, 2016
Latest reply on May 13, 2016 by Bryan Cole

Note: This is a post carried over from here:

I was unable to post an attachment when commenting on the thread, so to make sure the file is always available I've created another post that the source code attached and the instructions below.


I jerry-rigged the led_demo project to recreate the issue.  The (my) idea was to just add the KSDK 1.3.0 Platform code (for the FRDM-K22F) to the KBOOT package and call the default "hardware_init()" found in all of the KSDK examples.  The issue is recreated recreated if you follow these steps with JLink OpenSDA V2.1 driver installed on FRDM-K22F development board:


1. Install KBOOT 1.2 package (mine was extracted to a directory named "FSL_Kinetis_Bootloader_1_2_0")

2. Open the IAR project, "%INSTALL_DIRECTORY\FSL_Kinetis_Bootloader_1_2_0\targets\MK22F51212\bootloader.eww"

3. Make the freedom_bootloader - Debug project the active project. (Right-click "freedom_bootloader - Debug" > Set as Active..)

4.  Go to aforementioned project's options. (Highlight "freedom_bootloader - Debug" and press Alt + F7)

5. Change Debugger > Driver, to "J-Link/J-Trace" and click "OK"

6. Press Ctrl+D to Download & Debug the bootloader and press F5 to run the application when it breaks on main

7. You can now stop the debugging the bootloader by exiting IAR


Download user application to FRDM-K22F

1. Download source code in the attached zip file.

2. Unzip the contents to a directory

3. Open "led_demo.eww"

4. Build the "ksdk_platform_lib" project

5. Build the "led_demo_FRDM-K22F" project (note that the linker file used is in the same location as the led_demo.eww file, which uses places application at offset 0xA000)

6. Make sure "led_demo_FRDM-K22F" is the active project

7. Download & Debug the application, press F5 to run the application after it breaks on main()

8. At this point the RGB LED should be changing, just like it does in the normal led_demo (except blinking at a faster rate).  Don't stop the debugging at this point, continue below.


Make it happen

1. Now, press the "Reset" button on the FRDM-K22F board

2. Wait ~5 seconds (bootloader is waiting for peripheral activity)

3. If the user application ends up running, the debugger will break on main(). Press F5 to continue running.  Then repeat step 1 & 2 until you get the symptoms found below.

4. If the user application doesn't appear to be running, break via the debugger and observe where it is stuck--it will loop forever at this point, assuming it goes untouched.

5. If the clock is stuck, repeating the steps beginnging at step 1 may or may not fix the issue.  It is a shot in the dark as to whether it will get stuck or not.  I have tried this on two FRDM-K22F boards and Board 1 gets stuck anyways between 50%-75& of the time, and Board 2 gets stuck about 10% of the time.


Let me know if there are any additional questions or the source doesn't build.



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