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sorry if i bother u all too much..
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No worries - the forum exists for us all to help each other.
As for your clock divider - the code looks fine - the real question is the headache of the simulation job. I'm sure that you'll get a few different bits of advice on this. Personally I would break down the task into a few different objectives.
You've done your big simulation to show that your clock divider works with the correct frequencies - i.e. for a 33 MHz clock and a division of 16500000 you get a 1 Hz output.
Now you want to check that this interacts with everything else in the design which will be the case regardless of the frequencies involved, so change your division to something much quicker - everything based on the 1Hz clock will obviously happen much faster than in real life but you know that when you change your divider constant for synthesis, you will get the right result.
What I sometimes do is use the "--translate synthesis_off" and "--translate synthesis_on" comments to mask off bits from synthesis so that no code changes are required between simulation and synthesis.
constant division : integer := 16500000;
constant division_sim : integer := 165;
phttp://www.alteraforum.com/images/smilies/tongue.gifrocess(clk)
variable cnt : integer range 0 to 16500000;
begin
if(clk'event and clk='1') then
if(cnt=0)then
cnt:=division;
-- translate synthesis_off
cnt := division_sim;
-- translate synthesis_on
clkout<='1';
else
cnt := cnt-1;
clkout<='0';
end if;
end if;
end process cloc;
Basically what happens here is your counter gets loaded with the large value and then decrements to zero. At zero, your output goes high and the counter is reloaded. Now for simulation, you load cnt with division (16500000), then straight way before this value has any effect, you load cnt again but with division_sim (165). For synthesis, the translate pragmas mask off the second assignment and so cnt only gets loaded with division.
This way you can use the same code for (speeded up) simulation and (real time) synthesis.
Hope you find this useful.
Honored Contributor
