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Altera_Forum
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8 years ago

AM transmitter behaves weird (Cyclone II)

Hello. I tried to make AM transmitter and I got petty wird behavior. This code, which I post here was the only one I got working. Problems start appearing when I change div2(17) or div2(13) to any o...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

The below code is counting rising clock edges in a simulation, by working of the sensitivity list. When trying to synthesize it in hardware, the sensitivity list is ignored and it doesn't work as a counter. 

process (clk) 
begin
  if clk='1' then
    count <= count +1;
  end if;
end process;

To achieve consistent behavior in functional simulation and synthesis, you need to write 

process (clk) 
begin
  if rising_edge(clk) then
    count <= count +1;
  end if;
end process;