Forum Discussion
Altera_Forum
Honored Contributor
11 years agoSimulation problem with simple edge detector
I have a very simple edge detector and I'm confused as to why I get this very small blip (pulse) on my output when it detects an edge. I ran into this in a larger design so I simplified it down to a...
Altera_Forum
Honored Contributor
11 years agoThanks! I changed up my test bench it my simulation looks good now. Here is my new stimulus block in my test bench
PROCESS
BEGIN
INPUT <= '0';
wait for 190 ns;
wait until CLK = '1';
INPUT <= '1';
wait until CLK = '0';
wait until CLK = '1';
--wait for 20 ns;
INPUT <= '0';
WAIT;
END PROCESS;
Here is a screenshot of the simulation: http://www.alteraforum.com/forum/attachment.php?attachmentid=9577&stc=1 So am I correct in thinking that the simulator now executes the rising edge of input a delta delay after the rising edge of the clock more like a hardware circuit? Instead of the other way around where it took a delta delay/delays to execute the clock while input was technically high for an instant giving me that blip? I think I've got a handle on this now if this is correct.