AnsweredAssumed Answered

How do I resolve 'Can not enter background mode'?

Question asked by Andrew Perkins on Jan 31, 2015
Latest reply on Feb 5, 2015 by Tharon Hall

I have a K20DN512VLQ10 on a custom board and I'm attempting to debug the default Kinetis Design Studio project via a P&E Multilink Universal on Windows 8.1.


When I create a default project for the chip and immediately debug it, the target resets, and this is the output I get in the console:


P&E GDB Server, Version

Copyright 2014, P&E Microcomputer Systems Inc, All rights reserved


Loading library C:\Freescale\KDS_2.0.0\eclipse\plugins\com.pemicro.debug.gdbjtag.pne_1.1.7.201410171532\win32\gdi\unit_ngs_arm_internal.dll ... Done.


Command line arguments: -device=K20DN512 -startserver -singlesession -serverport=7224 -interface=USBMULTILINK -speed=5000 -usejtag -port=USB1 -USE_CYCLONEPRO_RELAYS=0 -FORCE_MASS_ERASE=0

Device selected is k20dn512

User Specified Hardware Selection : Interface=USBMULTILINK and Port=USB1

Connecting to target.

P&E Interface detected - Flash Version 6.10


Can not enter background mode  .


Unable to initialize PEDebug.


PE-ERROR: Failed to Initialize Target

Server running on

Connection from "" via

PE-ERROR: Target is not connected

Disconnected from "" via

Target Disconnected.


I have made two changes to the debug configuration:

  1. Unchecked 'Use SWD reduced pin protocol for communications' as the board has a 20-pin JTAG port.
  2. Changed device name from 'K20DN512M10' to 'K20DN512' as the package identifier for the chip is 'LQ', not 'Mx'.


Trying different combinations of these settings (using SWD, not using SWD, using different K20 device names) has had no effect. Interestingly, after the 'Can not enter background mode' message, two unprintable characters are echoed to the console (both 0x07).


I've searched this forum for solutions without success. Attached is an image of my debug configuration. Is there a specific configuration setting I'm missing?



kds config.png