Assertion to check if all bits get set atleast once in simulation for a multibit vector

In reply to rohitk:


// assertion to check if all bits get set atleast once in simulation for a multibit vector
import uvm_pkg::*; `include "uvm_macros.svh" 
module top; 
	bit clk, enb=1;  
	bit[3:0] fgs; // flags to check 
	default clocking @(posedge clk); endclocking
	initial forever #10 clk=!clk;   
	property p_flags; 
		bit[3:0] v=0; 
		enb |-> (1, v=v | fgs)[*1:$] ##0 (v==4'b1111 || enb==0); 
		// When enb gets set to 0, another attempt gets started in the Preponed region
	endproperty 
	ap: assert property(p_flags) enb=0;  

 initial begin 
     repeat(200) begin 
       @(posedge clk);   
       if (!randomize(fgs)  with 
       		{$countones(fgs)==1;}
           ) `uvm_error("MYERR", "This is a randomize error")
       end 
       $finish; 
    end 
endmodule  	
  

Ben Cohen
http://www.systemverilog.us/ ben@systemverilog.us

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