Randomize Non-random (State) variable using randomize() method of Class

The randomize() method can be used to temporarily control the set of random and state variables within a class instance or object.

When randomize is called with arguments, those arguments designate the complete set of random variables within that object; all other variables in the object are considered state variables.

The randomize method accepts the special argument null to indicate no random variables for the duration of the call. In other words, all class members behave as state variables.

Consider following Example:

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	class rand_mo;
	rand integer Var1;
	integer Var2;
	endclass
	program rand_mo_p_38;
	rand_mo obj = new();
	initial begin
	// Random variable: Var1, State Variable: Var2
	void'(obj.randomize());
	$display(" 1 : Var1 : %0d, Var2 : %0d",obj.Var1, obj.Var2);
	// Random variable: Var2, State Variable: Var1
	void'(obj.randomize(Var2));
	$display(" 2 : Var1 : %0d, Var2 : %0d",obj.Var1, obj.Var2);
	// Random variable: Var1, Var2
	void'(obj.randomize(Var1, Var2));
	$display(" 3 : Var1 : %0d, Var2 : %0d",obj.Var1, obj.Var2);
	// State variable: Var1, Var2
	void'(obj.randomize(null));
	$display(" 4 : Var1 : %0d, Var2 : %0d",obj.Var1, obj.Var2);
	end
	endprogram
	// Output:
	// 1 : Var1 : -902462825, Var2 : x
	// 2 : Var1 : -902462825, Var2 : -1241023056
	// 3 : Var1 : 69704603, Var2 : -1877783293
	// 4 : Var1 : 69704603, Var2 : -1877783293

view raw randomize_with_arguments.sv hosted with ❤ by GitHub

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