Question:
Is there a way to recover a locked Concerto F28M35x device with an unknown password?
Answer:
We have seen that accidentally locking a device most often occurs during application development in the lab. On Concerto we have the ability to keep devices unlocked while development is in progress. There is a bit in the OTP (PSWDLOCK) that controls this. On a fresh device this bit is 1. When the bit is 1 (i.e. during development) the password can always be read and thus the device can be unlocked.
To secure the device for production the user MUST program the password they desire AND program the bit in the OTP to zero. It is very important that they do both steps. Devices that have been deployed to the field and later the password becomes unknown cannot be recovered.
