I am trying to solve the below constraint but unable to get the right idea. So just randomizing the queue size in constraint block and solving in the post_randomize method the only solution? I even tried to replicate procedural solution in declarative way in constraint block but it is not working. …

That was meant to give you a hint to the approach. Generating a non-random series of numbers becomes trivial if you have a function that computes the kth element of the series. class A; function int series(int k); int n = 1; int t = 1; while (t < k) begin n++; t += n; …

Dear Dave, This approach gives output as '{1, 22, 333, 4444, 55555, 666666}. My requirement was '{1,2,2,3,3,3,4,4,4,4}. Also simulators like Synopsys VCS are saying “**” operator is illegal to use in constraints. So the code is not portable too. My goal is not to use “post_randomize” because I beli…

Dear Dave, Thanks for the solution.I should have put more effort into understanding your previous message. It is really a good idea to use a function in constraint when complex(this actually can help in solving many of my problems). But one question still bothers me is the usage of post_randomize. …

Constraint solving is most effective when all constraints can be applied simultaneously during randomization. Once values are generated in the post_randomize() function, they become unusable with the constraints. While this may not be necessary in every scenario, once values are set in post_randomiz…

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Constraint Pattern problem

SystemVerilog

constraint-randomization

dave_59 January 9, 2026, 6:45am 2

Constraint to print pattern 122333444455555 SystemVerilog

class pattern; rand int a[]; constraint c2 { a.size==6;} constraint c1 { foreach (a[i]) a[i]==(1*(i+1)*(10**(i+1)-1))/9;} endclass module m; pattern p; initial begin p=new; assert(p.randomize); foreach(p.a[i]) $display("pattern is %d",p.a[i]); end endmodule

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