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jzaghal
Joined: 31 Jul 2001
Posts: 213
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 25 Jan 2003 20:13 Re: PAL18L8 Decompiling ?? |
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Hi to all,
Please, can you suggest a way to decompile a protected PAL18L8.
Is,giving all the combinations on the inputs, and monitoring the o/p's
enough to do that, since this is a combanitorial device ??
Thanks for feedback. 
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sc/mp
Joined: 10 Feb 2002
Posts: 142
Helped: 1
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| 25 Jan 2003 23:16 |
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Hello
I ever saw 18P8 and 18V8 but never 18L8 !
According to the name it should be purely combinatorial
as you say, so try all input combinations and you have all
outputs.
Bye
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Ace-X
Joined: 25 Jan 2002
Posts: 594
Helped: 26
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| 26 Jan 2003 0:15 |
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I don't think that it is combinatorial. As far as I know output pins in these devices can be programmed to be registered, so the number of flip-flops in your case can be as many as 8. It means that this device can have up to 2^8=256 internal states. It will make you task much more harder to solve.
Good luck!
Ace-X.
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BENOIT
Joined: 22 Sep 2001
Posts: 86
Location: France
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| 26 Jan 2003 11:59 |
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two things;
if you have the Jedec of the PAL you can use the software
palasm there is a utility program that generate the equations of
the pal in correspondance to the pin names
if you have not the Jedec you have to use a tool as the PLD Analyzer
from RunFei (china) which allow you to retrieve with Approx. 99%
success the jedec of any secured PAL (up to 22V10)
this tool is very hard to find now but was available in the U.S a few
years ago;
you can get more details by looking at news:comp.arch.embedded
Archives ,
Most compilers come with a program to do that. The one I remember was called Jed2Eqn.exe this come for example with Opal Junior 2.1
from Harris Semiconductors,
@+
Regards,
MB.
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