In reply to rag123:
class matrix;
rand bit [4:0] arr [3][3];
constraint block_unique {
foreach ( arr[i, j] ) {
foreach ( arr[k, l] ) {
if ( ! ( i == k && j == l ) ) {
arr[i][j] != arr[k][l];
}
}
}
}
endclass : matrix
module tb;
matrix m1;
initial
begin
m1 = new();
repeat(10)
begin
if (!m1.randomize())
$display("Error");
$display ("%p",m1.arr);
end
end
endmodule