topic Re: Censored Device - Password Known in Other NXP Products

Censored Device - Password Known

vmed5 — Thu, 30 Oct 2014 13:57:29 GMT

Hello,

It seems that I have successfully censored my device by changing the censorship control word, as I am no longer able to connect during internal boot via the Nexus Port. I am using pemicro's ICDPPCNEXUS as my debugger with a MPC5566. Within the debugger there is an option to enter in the Censorship password on a reset. My question is, can i enter my password in here to uncensor the device and is there a specific way the password must be entered (i.e. password = FEEDFACECAFEBEEF must be entered as = CAFEBEEFFEEDFACE), or can i not use this method to uncensor my device. Each time i attempt to uncensor my device, I am prompted with "Debugger retrying force to background mode. Can not enter background mode."

Thanks,

Victor

Re: Censored Device - Password Known

lukaszadrapa — Tue, 04 Nov 2014 08:41:06 GMT

Hi,

password should be set as FEEDFACECAFEBEEF. Swapping is necessary only on MPC56xx devices that have C90LC flash (I'm not absolutely sure now, but if I can remember, pemicro swaps the password automatically).

How did you set Censorship Control word and Serial Boot Control word?

Lukas

Re: Censored Device - Password Known

vmed5 — Tue, 04 Nov 2014 14:14:45 GMT

Hi Lukas,

I have set the censorship control word(at 0x00FFFDE0) to 0x33CC and the serial boot control word(at 0x00FFFDE2) to 0x55AA. Since I know the password in flash to be FEEDFACECAFEBEEF, can I attempt to uncensor the device using my PEMICRO to work on it, or must I use serial boot to run the code in the application note?

I have followed application note 3787 as a reference for setting this up:

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

Thanks,

Victor

Re: Censored Device - Password Known

lukaszadrapa — Fri, 07 Nov 2014 12:14:08 GMT

Hi Victor,

I found out that on MPC55xx devices it is not possible to unlock the device via JTAG using password. This works only on newer MPC56xx.

On MPC55xx we can use password only in serial boot mode.

Yes, to uncensor the device, serial boot mode or external boot mode can be used as described in AN3787.

Regards,

Lukas

Re: Censored Device - Password Known

vmed5 — Mon, 10 Nov 2014 15:55:13 GMT

Thanks for your help Lukas.

-Victor