MPC5606B invalid RCHW

[jan_vdh]

Hello,

I've programmed an MPC5606B chip to use the private password & censorship turned on. However, the chip was still empty, so has an invalid RCHW and reset vector. Now, the BAM code seems to run & download through serial, but for any possible password. Then it seems to go into static state, or at least does not run or execute the downloaded BAM code.

Is there any way I can recover this chip?

Many thanks

[jan_vdh]

 Thanks for the reply. That explained the weird behavior . One more question - once a chip is configured as public pw & censored, but I know the private password, can I still disable the censorship in the BAM bootloader by writing the private password to the PWCMPH & PWCMPL registers?

Many thanks

[davidtosenovjan]

Yes, you can temporarily disable censorship (until next reset) by entering the password over serial boot communication, here again in reverse order.

[jan_vdh]

Am I wrong to think that the chip only accepts the public password (feedface cafebeef) during the serial boot communication when configured to use the public password? I'm wondering if I can still somehow uncensor the chip in that configuration.

Thanks

[davidtosenovjan · Accepted solution]

If configured for public password, you are entering public password. If private password, then you are entering private password.

[jan_vdh]

Thank you for the reply. The scenario I'm dealing with is as following:

* The chip is configured to use public password & is censored.

After entering the public password I can execute the BAM code. Now I'm wondering if the downloaded BAM code can disable censorship by writing the private password to the PWCMPH and PWCMPL registers?

[davidtosenovjan]

No, what you are describing is lock out. In this case MCU is censored forever.

[davidtosenovjan]

Here you may see example codes for censorship on this device:

https://community.nxp.com/t5/MPC5xxx-Knowledge-Base/Example-MPC5604B-Censorship-CW210/ta-p/1123992

Common issue could be that password needs to be entered in reverse order i.e. 0xCAFE_BEEF_FEED_FACE (for private password 0xFEED_FACE_CAFE_BEEF).