Constraint for repeating numbers in an array in a unique pattern

SystemVerilog
, ,
3

In reply to dave_59:

Thanks you as always Dave. I got most of the code and updated a couple of lines to suit the requirements.


module top;
  class C;
    rand bit[4:0] A[], uniq_A[];
    rand bit [7:0] length,k;
 
    constraint sizes { 
      length == A.size();
      length % k >= 1;
      uniq_A.size() == (length/k) +1;
    }
    constraint uniqueness {
      unique {uniq_A}; 
      foreach(uniq_A[i]) {
        if (i<(uniq_A.size()-1)) {
          A.sum() with (int'(item==uniq_A[i])) == k;
        }
        else {
          A.sum() with (int'(item==uniq_A[i])) == 1;
        }
      }
    }
  endclass
  C c = new();
  initial repeat(5) begin
    assert(c.randomize() with {length == 17; k== 4;});
    c.A.sort();
    $display("%p", c);
  end
endmodule

Surprising one of the simulators does not like this constraint and takes a really long time and I had to kill it. Anyhow cdns, questa worked.