Hi, Li:
I using the OSJTAG download to MCU, the development board is TWR-K21F120M Tower Module
detail process:
1. OPEN TWR-K21F120M - J8 let MCU(MK21FN1M0VMC12 ) no power.
2. Connect J1(JTAG) to my design board (MCU: MK21FN1M0VLQ12), there is pin to pin.
3. Connect microUSB cable to J2 and power on.
4. CodeWarrior 10.6 download to my design board.
5. fail, find OSJTAG but not find MCU(MK21FN1M0VLQ12).
Only TWR-K21F120M downloaf is OK.
Thanks.