topic Re: understanding security state in S12 / MagniV Microcontrollers

understanding security state

thorstenmumm — Tue, 15 Aug 2017 19:19:22 GMT

Hello,

i try to secur my S12ZVC but i get a problem with my programm or understanding this funktion

when i try this exampel as global variable

const unsigned char flash_array[] @ 0xFFFE08 =     // secure the device without backdoor key
   {
    0xFF,   //0xFFF08
    0xFF,   //0xFFF09
    0xFF,   //0xFFF0A RESERVED
    0xFF,   //0xFFF0B RESERVED
    0xFF,   //0xFFF0C FPROT
    0xFF,   //0xFFF0D DFPROT
    0xFF,   //0xFFF0E FOPT
    0xFC,   //0xFFF0F FSEC - SECURED without backdoor key
   };

my code / modul dosent works! and i can not debug and get the massage it is secur

When the Chip is unsecur me code/ modul works fine.

where is my mistake? I wil only protec the chip for reading by a other one after he is programm

what have i to do?

Thanks for help

Re: understanding security state

danielmartynek — Tue, 15 Aug 2017 21:06:08 GMT

Hi,

When the chip is in the secure state, the debugger has no access to the chip.

It can only mass erase the flash which will unlock the MCU.

Regards,

Daniel

Re: understanding security state

thorstenmumm — Wed, 16 Aug 2017 10:39:20 GMT

Hi Daniel,

thats clear, that the debugger dosent work.

but it work not when i built the projekt and flash it to the modul. The modul dosent works !

At first a LED shold go on, but they dosent work.

When i delete the securi aray variable its works fine

here are my problem, whats going wrong by flashing the modul?

Re: understanding security state

danielmartynek — Wed, 16 Aug 2017 15:55:21 GMT

Hi Thorsten,

The code is correct.

Please disconnect the debugger and reset/replug the MCU after it has been loaded and secure.

Regards,

Daniel

Re: understanding security state

thorstenmumm — Thu, 17 Aug 2017 17:18:38 GMT

Hi Daniel,

it dosent works!

When i write this arry to the variables it dosent works with anny of my moduls.

I have a other module this code ist written with out prozessor expert and i past the code to it. This module has the same problem! It dosent start when i reset it or turn it on.

when i delete the arry its works

what can help? i will only protect the code for reading by a other one. Can i youse a other way?

What can help?

Thanks Thorsten

Re: understanding security state

danielmartynek — Thu, 17 Aug 2017 19:28:06 GMT

Hi,

There might be a problem with the processor expert. Because if the processor expert writes to this address, you cannot rewrite the flash, it should be in erased state. Otherwise It could go to the machine exception due to a double bit ECC error. Have you tried a simple blink program without processor expert? If not, please try it and let me know.

Regards,

Daniel

Re: understanding security state

thorstenmumm — Sun, 20 Aug 2017 05:34:48 GMT

Hi Daniel,

i think it works now! when i wrote the flash, processor expert.took a incorecct datei they was emty. it was at all projekt the same.

now the controler works after flashing and i get the massage it is secur when i will read

i think tha ist now ok

and i am raedy for the next problem... i'm sure it cames :smileywink:

Thanks Thirsten