MPCxx Censorship

[dpastl]

Hi There,

I'm investigating the censorship settings in the MPC56xx series and one thing that I've not understood from the documentation is: how permanent are these settings.  If I set the flash censorship on, do I need to go through the recovery process to get it back or is that process only if the serial password has been forgotten?

Thanks,

David

[davidtosenovjan]

Censorship is very sensitive thing. It is needed to use it very carefully, because an inappropriate usage can lead in making the device useless. If you accidentally erase shadow flash there is no chance to recover it (unless it had been though about before).

If your device is censored and you don’t have any pre-prepared recovery code located in the internal flash memory, there is no way how to unlock it and everything you can do is to order new sample, and re-solder it instead of the censored one.

Thus I would recommend to study following appnote:

http://cache.freescale.com/files/32bit/doc/app_note/AN3787.pdf

[kenwoodruff]

David,

I have a similar question. I am working with a MPC5606B and haven't yet censored it, but by application will require it.  App note 3787 that you referenced seems to be for MPC55xx and MPC563x devices. Does it also apply to the MCP5606B? I currently have only have a couple of working samples and don't want to "brick" one at all as I learn the censorship details. Is there another app note for the mpc560x devices?

thanks

ken

[dpastl]

Hello David,

I've read through that document a couple times and I guess I'm just confused about exactly how to achieve what we want: locking down the device so that the flash cannot be read.  We'd still like to be able to program it via JTAG if at all possible.  I've changed the serial password to try and password protect the device but that made little difference.  Now that I've locked down flash by changing the first censorship word I can't communicate with it.  We've got a few more test devices here but I'd rather not brick them all :smileygrin:.

Thanks!

David