Hi, Unfortunately, we have got the 0L85D mask-set. probably a 10k chips. Sit and cry :-( Ok,"Un-secure" It's some solution on today. But, When I'll un-secure MCU by Password/Backdoor key via SCI the MCU stays un-secured. I can keeping the Flash and EEPROM un-secured but, it is dangerous. Some one can read the content the FLASH and EEPROM via BDM (to next reset of course) at this moment. am I wrong? Dariusz --- In , Doron Fael <doronf@n...> wrote: > Dariusz, > > You didn't mention what mask-set of the MC9S12DG128 you are using. > > For security, I would advise against using the earlier mask sets - 0L85D or > 1L85D. These earlier mask-sets don't have security fully working, and may > also have some bugs that prevent the Flash and EEPROM from being written > when the part is secured (I believe there was a recent post to this list > about such a bug on an earlier mask sets of the MC9S12A256). > > MC9S12DG128 mask sets 0L40K - 4L40K, and 3L58S suppose to have the security > fully working. These mask sets also allow writing to the Flash and EEPROM, > while the part is secured. Please note there are two separate mechanisms > for the Flash and EEPROM - security and protection. On parts that have > security fully working and free of initial silicon bugs, you can keep the > security mechanism on, and write to the Flash and EEPROM by keeping the > Flash and EEPROM un-protected. > > Hope this helps, > Doron > Nohau Corporation > HC12 In-Circuit Emulators > www.nohau.com/emul12pc.html > > At 23:51 01/11/2004 +0100, you wrote: > >Hi, > > > >I've a problem with processor security against reading the content of > >FLASH/EEPROM by unauthorised persons. > > > >I've read the documentations and application notices (AN2206 etc.) but I'm > >still unsure how the security should be made. > >My project based on the MC9S12DG128 processor, which works in SINGLE CHIP > >mode. > >Program uses EEPROM memory for configuration parameters. > > > >First version of program is loading via BDM. Next versions are loading via > >SCI (upgrade). > > > >My question: > > > >1) When I get MCU to secured mode (by set @0xFF0F = 0x80) I lose access to > >EEPROM memory. > > I have to access to EEPROM. What should I make? > > > >2) It is possible secure BDM interface without secure Flash and EEPROM > >memory? I need upgrade program via SCI and need access to Flash via SCI. > >When I get to secured mode I don't have access to Flash via SCI. How to > >resolve this? > > > >3) I need upgrade program via SCI and need access to Flash via SCI , and > >need to have secured MCU (BDM interface) in the same time. > >But, When I unsecure MCU by Password/Backdoor key via SCI - MCU stays > >unsecured. > > > >It is dangerous. Some one can read the content the FLASH and EEPROM (to > >next reset of course) at this moment. > > > >What is solution of this? > > > >I would be grateful for any ideas. > >Dariusz Kusinski > |