I'd like to develop a firmware running on any FRDM-Kxx that is capable of RAM writing/reading on/from a KE02 device through SWD debug port by SWO and SWI pins. Is it feasible? How?
You can take the OpenSDA project (it is available as source I believe) which generally runs on a K20 (or similar) and supposedly bit-bangs the SWD protocol to read/write/program/debug SWD based processors.
You should be able the use the same routines to do what you want to do.
Alternatively you can take any FRDM-Kx board and use its on-board OpenSDA interface connected to other boards - there are various tutorials/blogs about doing this - eg. https://mcuoneclipse.com/2014/08/09/hacking-the-teensy-v3-1-for-swd-debugging/
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