How do you know that it's protected ??

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Vonn

Joined: 06 Oct 2002
Posts: 254
Helped: 2

20 Oct 2003 8:47 galep y 16f877

Hi All ,
How do you know that the controller is protected ?
I have red a Pic controller and the programmer doesn't give me any
message and the output file was not FF's or 0's NO it have a data !!!
When i tried to program similar controller with this file it doesn't work .
that means the data i have red was not correct .. I retried to read
another one ; i had the same checksum ..
I thought that when i try to read a locked controller either the
programmer will fail or i will got an FF or 0's file . Am I right ? Does any
body face this before ?

M!k

Joined: 22 Apr 2002
Posts: 871
Helped: 79

20 Oct 2003 9:15 Re: How do you know that it's protected ??

you can always read the configuration word containing the protection bits

Mik

sadat007

Joined: 01 Jan 1970
Posts: 428
Helped: 6
Location: Pakistan

20 Oct 2003 9:56 Re: How do you know that it's protected ??

Hi,
Dont have any idea on PICs but 89C52 etc gives FF when full protected.

Vonn

Joined: 06 Oct 2002
Posts: 254
Helped: 2

20 Oct 2003 12:15 Re: How do you know that it's protected ??

Do you mean that i could know if it's protected or not by reading the configuration word
Is that available for all pic families ?

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C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

20 Oct 2003 13:27 Re: How do you know that it's protected ??

Maybe this can help you:
I checked with two code protected PIC's (16F628, 16F877).

When you read them back you only get 0x00 instead of the programmed data, you can read back the ID locations (at 0x2000 to 0x2003) and the configuration word (at 0x2007).

If I remember correct a 16F84 could read back each second byte of data but the other byte was alwas 0x00 (but each instruction is composed of two bytes of data) ...

best regards

mrcube_ns

Joined: 10 Apr 2002
Posts: 429
Helped: 11
Location: Dark side of the Moon

20 Oct 2003 13:55 Re: How do you know that it's protected ??

Some uC have a few bites for protection of code. In that case protection is for some parts of code not for all, so you can choose which part of code you want to protect.

In PIC's case if protection is on you read 00 on all PIC's I work with.

Regards.

Mr.Cube

Vonn

Joined: 06 Oct 2002
Posts: 254
Helped: 2

20 Oct 2003 14:25 Re: How do you know that it's protected ??

My PIC is 16C55a and the file I red is attached ; if any body can tell me if this is a valid code or not and why that will be appreciated

Sorry, but you need login in to view this attachment

M!k

Joined: 22 Apr 2002
Posts: 871
Helped: 79

20 Oct 2003 14:56 Re: How do you know that it's protected ??

I'd assume that it's not code protected because the first 0x80 bytes (= 0x40 words of totally 0x200 usable words) are too different; also the 16C55 can't be protected partly. But you didn't read the configuration word @ 0x2007 which include the protection bits....

Mik

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

20 Oct 2003 15:03 Re: How do you know that it's protected ??

My Programmer (Galep 4) reports that code protection is on Sad

I assume the file you posted is a binary file because the .hex extension does not make sense as the file must be ASCII then ...

And to M!K the configword for the 16C55A is at 0xFFF

best regards