Hi,
The new Kinetis devices are supported by KDS and most of the legacy devices are supported as well. CodeWarrior will not support new devices.
If you are referring to this Tower board Kinetis K21 120 MHz Tower System Module|Freescale this one has on board a MK21FN1M0VMC12 device that is supported by KDS v1.1.1, you can find it in the New project wizard with the label MK21FN1M0xxx12.

:smileyinfo: Post your questions in a dedicated space, for example Kinetis Design Studio there all the members in the community will easy see your question.
I hope this information can help you.
Regards,
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