Kinetis Flash ERASE failure

[saurabhjhamb]

Helloe folks,

I am working on a custom board using MKW01Z128CHN.

There are few boards that I am unable to program using JLink (SWD mode)

All ICs are new from factory, assuming flash would be empty. Hence RST pin would toggle as in snapshot attached.

In some cases, as attached logs show, I am able to successfully unlock flash using jlink commander as well, but unable to ERASE flash.

Kindly share your thoughts...really appreciate any help.

Attached JLink commander Logs, and couple of snapshots (RST pin toggle & JFlash chip erase error)

[jasonclifton]

I have fought this issue with a different microcontroller (kinetis K20).  I never did figure out exactly what was causing it.   I did however figure out how to avoid it in my case.  I discovered if I unplugged the Jlink from the computer usb before plugging my programming header in and unplugged it after programming but before unplugging the header all my problems went away.  I suspect that voltage being on swd lines before the microcontroller powers all the way up may be able corrupt the flash

Hope this helps