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constraint dist 'others'

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How can I randomize with a dist and specify a weight for values not being inside a range?

 class randclass;
    rand logic [3:0] randvalue;

    function void post_randomize();
      $display("value: %0d",randvalue);

   constraint inside_practice {
     randvalue dist {
       [3:4] :/ 50,
       !(inside {[3:4]}) :/ 50    //<---  I try to have a sort of 'others' category here

module top;
  randclass randclass;

  initial begin
    randclass = new();
    repeat (10) begin 


Reference:  https://www.edaplayground.com/x/cV5 


shaking off the rust after a SystemVerilog hiatus,



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  • 5 months later...
  • 4 years later...

Since the dist works only with explicit values, you can't use conditions in the distribution itself.

But, you can apply a distribution on the condition instead. This works in Questasim

constraint inside_practice {
  (randvalue inside {[3:4]}) dist {1 :/ 50, 0 :/ 50};
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