Why Censoring the MPC5643L using 0x55AA55A0 works and 0x55A055A0 doesn't?

[YazenAlali]

Hi,

I am confused about why I am not able to uncensor the MPC5643L using PEMirco debugger and code warrior when writing 0x55A055A0 to the NVSCI register but it works fine with 0x55AA55A0? I am using a single chip bootloader mode so not a serial boot mode.

Thanks,

[YazenAlali]

Following up with this issue. Here are some tests I have tried out that further explains the issue:

1. Censor Register (NVSCI):0x55A055A0 / Password (NVPWD): 0x0008008008008000 (Didn’t work)
2. Censor Register(NVSCI): 0x41284422 / Password (NVPWD): 0x0008008008008000 (Didn’t work)
3. Censor Register(NVSCI): 0x41284422 / Password (NVPWD): 0xFEEDFACECAFEBEEF (Didn’t work)
4. Censor Register(NVSCI): 0x55AA55A0 / Password (NVPWD): 0x0008008008008000 (Worked)
5. Censor Register(NVSCI): 0x55AA55A0 / Password (NVPWD): 0xFEEDFACECAFEBEEF (Worked)

Which means if you change the value of SC (serial censorship control word) in the NVSCI register other than 0x55AA it will not work when trying to uncensor the JTAG using regardless of the password.

[davidtosenovjan]

Yes, I think it works this way.

Although it is not explicitly stated, if it is configured for entering private password in serial boot mode, JTAG password is not accepted.

[Matthew2154]

Glad you like it. We have been using this for several weeks now and it seems to be going nicely.

[davidtosenovjan]

Some derivatives would have 0x55A055A0 as configuration leading in permanent lock-out of the device (for instance MPC5604B) but I haven't found any prove in the MPC5643LRM so theoretically it should work. Do you have valid password configuration during this setup?

[YazenAlali]

Thanks for the reply.
Yes I have the default password still in there as = 0xFEEDFACECAFEBEEF.
Interesting thing what you are saying about 0x55A055A0 could lock forever and I picked it up for my test by chance

[davidtosenovjan]

How you are entering the password? Please note that 32-bit words in 64-bit password have to be swapped when entering into the tool (i.e. if the password is 0xFEEDFACECAFEBEEF it should be 0xCAFEBEEFFEEDFACE)

[YazenAlali]

I am using PEmicro debugger via Code Warrior 10.6, before initializing the debug session it will ask me for the password and I would enter it there. Interesting that you are saying it should be swapped as when 0x55AA55A0 is in NVCSI, 0xFEEDFACECAFEBEEF would work fine.

[davidtosenovjan]

Could you provide exact device part numbers (all lines printed on the chip)? Thanks

[YazenAlali]

yes sure, the device number on the chip: 
SPC5643LMLQ1
2N89D
QRF1616E

Thanks,