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Hi everybody,
I am currently using Quartus II 9.0sp2 Web Edition in order to program an FPGA for a research project ( I am a trainee, my knowledges of quartus are quite fresh).
I have some compilation/simulation problems:
1) Sometimes my code does what it should do, but sometimes it does not AT ALL ( the simulation completely differs and not only for the block I have actually modified) and I have to change very small details such as:
"if counter>=2 then " in "if counter>1 then ".
or
if counter=2 then counter:=counter+1 ; in
if counter=2 then counter:=3;
and then it behaves exactly (not every times) like I want.
I don't know where this problem could be from, but I am wasting a lot of time in few modifications and compilation (near 8 mins/full compilation)
2) An other problem which could be linked to this is that I Have counters which doesn't count properly (and my state machine becomes crazy):
- some values are skipped
- some values are in the wrong order (3,2,5,4,7,6,9,8 instead of 1,2,3,4,5,6,7,8,9)
the worst thing: some "positive range 1 to 56" equals 0. the point is that even if the values are not good (in the simulation window) the behaviour could be the good one. that is why i would like to know if someone has already met this kind of problems before posting my code. Thank you for your answers
Denis
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Hi Denis,
there are a lot of possiblities which can cause such behaviour. Did you constrain your design ? Setting for clocks, Inputs, outputs are neccessary, in order to guide the synthesis engine. How did you generate your clocks ? Best way to get help is to post your Quartus project together with the source code.
Kind regards
GPK
Honored Contributor
