How do I put the constrained value into the 2D array in constraint by separately?

SystemVerilog
1

This question is related with How to create random dynamic 2D arrays in SystemVerilog? | Verification Academy

How do I put the constraint value into the 2D array in constraint by separately ?


class A;
rand logic [3:0]  width;
rand logic [3:0]  height;
rand logic [3:0]  DA[][];
//rand logic [3:0] [] DA2 [][];
//rand logic [3:0] [][] DA3[][];

  constraint con_A{
    width inside {[1:5]};
    height inside {[6:9]};
    DA.size == width;
    foreach(DA[i]) {
      DA[i].size == height;
       DA[i] inside{[1:5]};
/*
      foreach(DA[i][j]) {
      DA[i][j] inside {[6:15]};
      }
*/
      foreach(DA[i,j]) {
      DA[i][j] inside {[6:15]};
       }
    }
  }
endclass


module test;

A a=new();
initial begin
  if(!a.randomize())
  $error("Error_Randomize");

  $display( "a.width:%0d, a.height:%0d", a.width, a.height);
  foreach(a.DA[i,j])
    $display("i:%0d, j:%0d, a.DA:%0d", i ,j,  a.DA[i][j]);

end
endmodule

As you can see the code. I put the constraint value into the 2D array by using “$urandom_range()” by separately.

Q1. DA[i] inside{[1:5]}; is faced error with

  • Error: testbench.sv(16): (vlog-2728) Inside operator requires a singular type.
    – Compiling module test
    ** Error: testbench.sv(16): (vlog-2728) Inside operator requires a singular type.
    How do I put the constraint value into the 2D array in constraint by separately ?

Q2. What is the difference between

 foreach(DA[i][j]) {
      DA[i][j] inside {[6:15]};
      }

and

foreach(DA[i,j]) {
      DA[i][j] inside {[6:15]};
       }

?

2

In reply to UVM_LOVE:

foreach(DA[i]) iterates over the first dimension of the array. Each DA[i] represents an array of the second dimension with
height elements.

foreach(DA[i][j]) is illegal syntax. If you had declared **i** outside the foreach loop, it is unclear if you wanted to iterate over just the second dimension using the value of i as a constant, or both dimensions. foreach(DA[i,,j]) is the correct way of iterating over a 2 dimensional array.