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Altera_Forum's avatar
Altera_Forum
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15 years ago

Track signal in Verilog testbench for limited time

Hi everybody,

And TGIF !! (Thank goodness its friday, I see a beer in my future !!).

A Verilog question; I want to track a signal at every clock edge

in my testbench, but only when I activate a "switch" variable.

Such as:

v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} st1\:*{behavior:url(#default#ieooui) } #100 activate_signal_tracking = 1'b1;

test_status = signal_to_track;

#100 activate_signal_tracking = 1'b0;

So I want test_status to get the value of signal_to_track at every clock edge, but only while the activate_signal_tracking is set.

It would be good be able to track different signals also.

Not quite to simple I have found after trying various ideas, seems like I need a verilog task which I turn on and off somehow ?

The monitor statement will print changes of the variable to the screen,

but I want to track the test status.

Thanks a bunch for the help, whoever gives the right answer and is close to Freiburg Germany gets a beer from me tonight, lol !! :)

Have a good weekend !

Eric

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Use always block with if conditions. Such as: 

    
always @(posedge clk) begin : track_it
  if (activate_signal_tracking) begin : active_track
   test_status = <my_path>.signal_to_track;
   // .. more such signals to track if needed
  end : active_track
end : track_it

    If you use SystemVerilog you can also use the iff gating as in: 

    
always @(posedge clk iff activate_signal_tracking) begin : track_it
   test_status = <my_path>.signal_to_track;
   // .. more such signals to track if needed
end : track_it

    HTH

    Srini

    www.cvcblr.com/blog
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Hello Srini,

    Just got back from vacation, thus the late reply.

    Thats pretty much how I wrote the testbench code,

    thanks a bunch !!

    Cheers,

    Eric