Why do I get "object std is not declared" error when I use std::randomize?

Question

I am trying simulate a SystemVerilog code for an N-bit full adder, but I am getting this error:

Error (10161): Verilog HDL error at full_adder_tb.sv(73): object "std" is not declared. Verify the object name is correct. If the name is correct, declare the object.

Why is it saying "std" is not declared? I used quartus prime software to simulate the code.

Here is my code for testbench.

module full_adder_tb;

    timeunit 1ns;
    timeprecision 1ps;
    
    localparam N = 8 ;

    logic signed[N-1:0] A,B,S;
    logic ci,co;
    
    N_bit_adder #(.N(N)) dut(.*);
    
    initial begin
        A = 8'd80 ; 
        B = 8'd12 ;
        
        #1 assert({co,S}==A+B+ci) 
            
            $display("OK");
            
        else $error("Not OK");
        
        repeat(10) begin
            #9
            std::randomize(ci);
            
            #1
            
            assert({co,S} == A+B+ci) $display("OK");
            
            else $error("Error occurred");
        end         
    end
endmodule

Does anyone know a solution for this?

I searched in different websites, but there is no error in the code seems to be. But, it is giving a error message "std" is not declared.

toolic · Answer 1 · 2023-08-27T11:56:15.140

I do not get any errors with 2 other simulators. Try your code on EDAPlayground.

It could be a bug in Quartus, or perhaps you need to enable this feature somehow. Refer to the tool documentation.

Your code may work if you simply omit std::

        randomize(ci);

As an alternative to std::randomize, you could try:

        ci = $urandom_range(1);

Refer to IEEE Std 1800-2017, section 18.13.2 $urandom_range()

Why do I get "object std is not declared" error when I use std::randomize?

1 Answers1