Hello @dzinks0007,
Could you download it from Microcontroller Symbols, Footprints and Models | NXP Semiconductors?
In Search for Symbols, Footprints and Models, please type the device MK20DX256VLK10.
There is not needed to write the letter R (Packaging Type).
Click on BSDL -> Request file, fill the form and click on Submit request.
[Part Details of MK20DX256VLK10]
Warm regards, Raul.
