just like the above two posts i m trying to use FRDM-K66 Board to programme/Debug my custom board with KV4x.
K66 Does not have jumper on SWD_CLK Pin as KL25Z and K64F has....SWD_SDA and SWD_CLK pins are direcly connected to Target mcu k66.
so i have decided to cut the power of k66..so by turning off it i can connect my kv4x to 10 pin connector and programme it.
for that i have cut the link of j20 jumper.
i m using j9(10 pin connector) on frdm-k66 board to program my custom board with kv4x..
custom board is powered externally...
not using 3.3v from 10 pin connector as i have cut j20.
frdm-k66f has j25 jumper for reset ...with that jumper on/off i can programme kv4x...but its not working everytime...
i even tried cutting j5(jumper connecting k20 to reset pin of k66).
i have cut the j5 track and using k20 pin direcly connect to reset pin of my custom kv4x board.
i m using MCUxpresso.
I have updated onboard debugger(PEMicro OpenSDA v2.2 Bootloader) on FRDM-K66.
And it does not have restrictions on the target chip as i can programme my custom board with KV4x..
Problem is i have to follow perticular sequance for programming...
Note : Custom Board is powered externally as i have cut j20 track...(Custom Board do not get 3.3v from 10 pin connector)
1. Power on custom Board with KV4x
2. Power on FRDM-K66 Board (with jumper j25 connected on pin 1 & 2)
3. After 2-3 sec remove jumper j25 (jumper is totally removed..all pins 1,2,3 are open)
then i can programe my custom board one time....to programe it further i have to repeate sequance again..