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How safe is my program???

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foosm

New Member
hi all, i have one question as followed:

If i had flashed my working program into my PIC16F877, would anyone be able to get my souce code if he/she managed to lay hands on JUST the flashed microcontroller ???

Thank you.
 

kinjalgp

Active Member
Yes, it is possible to read-back your code if you have not locked the uC using its security fuses.

After programming, lock your microcontroller so that its difficult (I won't say impossible over here...) to read the flash contents. Almost all programming software have facility of setting security bits.
 

Sherif Welsen

New Member
kinjalgp said:
After programming, lock your microcontroller so that its difficult (I won't say impossible over here...) to read the flash contents. .

I wanna know how one can read my code back even if I lock it ???
Thanks in advance
 

kinjalgp

Active Member
Even I don't know how exactly it is done and I am not at all interested in doing or knowing it. But at many places on the net I have read that some people have found out a way to read locked code out of some very popular controllers and one of them is PIC16F84 (if I remember well).
 

foosm

New Member
so how do i set the security fuse ??? where in mplab ??? and one more thing, is this security fuse thingy reversible (ie can i switch it on /off as and when i like it)???
 

kinjalgp

Active Member
If you are using any of the MICROCHIP's PIC programmers (like PICSTART PLUS) then it is possible to set it in MPLAB since it incorporates software for these programmers also.
For other programmers, the programming software has this option somewhere in the window where you set the oscillator type and other programming options.

Yes, the security bits are resetable (only in FLASH ROM versions of PICs).
Once you erase the FLASH, it becomes as good as newly bought one. The bits are automatically cleared on erasure of flash.
 

Surge

New Member
I am trying to make PIC16F877 programmer now a days! ,I know this has been successfully done with 89c51 chips .Actually what they DEVILS :twisted: do is they delay the erase pulse using MMVs which applies a shorter pulse and then terminates the programmer. Now what does that means to you ?

Simple when the programmer tries to erase the data it first erases the Fuse bits and then the FLASH ,Now if one could stop it just in the bigining and thats in nano seconds then It could break the FUSES and not the entire data which could be read back .

YOUR PRECAUTIONS TO BE TAKEN

1) FIRST LOCK THE MCU THOROUGHLY.
2) USE SMD VERSION OF MCU AND DIP THE ENTIRE UNIT IN EPOXY :wink:
3) SECRETLY BRING THE PROGRAMMER TERMINALS OUTSIDE ENCRYPT
THEM ,YOU CABN DO THAT AS YOU ARE USING SMD VERSION INSIDE EPOXY .

THIS WILL MAKE VERY HARD FOR THE :twisted: TO BREAK OR EVEN FIND PROGRRAMING LEADS IN THE SYSTM SAY RB6,RB7,RB3 JUST ENCRYPT THEM .

4) IF YOU ARE MAKING SOME VERY SECRET PROJECT USE ANOTHER MCU TO ENCRYPT THE PROGRAMMING PINS OF THE MAIN MCU .

HOPE YOU LIKED MY IDEAS!

Good Luck
Surge
 

Surge

New Member
Friend kinjalgp , From where did you get the software to make that lovely logo I need the software to make mine as now I have started using PIC uCs along with Cygnal aswell :wink: so I will need a logo like that !

Surge
 

kinjalgp

Active Member
Now I don't know what Cygnal and PICs has to do with the logo. :lol: But anyways, I made it in MSPAINT (if you believe it). It's quite simple to make something like that. The logo has only 4 frames. I compiled the GIFs in Ulead GIF Animator that came with my scanner.
 

Surge

New Member
Hi,
That is simple It means I will be comming to this forum regularly like I go to 8052.com and Cygnal Forums ,so I must be fully prepaired :lol:
I feel the forum is also a wonder and full of wealth of information .Thanks I too used the Ms paint and have come to find that making a Logo for this site is much tougher than making a PIC programmer :wink: it took me so much time .
 
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