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Randomize

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Overview

In Verilog, randomization refers to the process of generating random or pseudo-random values for variables or signals during simulation. Randomization is used to create various test scenarios, stimulate different input conditions, and uncover corner cases in a design's behavior. It's a crucial technique in functional verification to ensure that a design functions correctly across a wide range of possible inputs.

$random
$urandom
$random_range( min, max )

Theory Questions
Coding Questions 
    module top;

    reg [31:0] RAND;

    initial
    begin
        RAND = $urandom;
        RAND[0] = 1;
        
        $display("RAND : %0d", RAND);
    end

endmodule

    function getNum;
    return $urandom%100;    
endfunction

module top;

    reg [31:0] RAND;

    initial
    begin
        RAND = getNum();
        
        $display("RAND : %0d", RAND);
    end

endmodule

    function getMaxMinRange( integer max, integer min );
    return ($urandom%(max-min))+min+1;    
endfunction

module top;

    reg [31:0] RAND;

    initial
    begin
        RAND = getMaxMinRange(30,5);
        
        $display("RAND : %0d", RAND);
    end

endmodule

    function getRand;
    return ($urandom/3)*3;
endfunction

module top;

    reg [31:0] RAND;

    initial
    begin
        RAND = getRand();
        
        $display("RAND : %0d", RAND);
    end

endmodule
    Locked Solution
    Locked Solution 
    function integer getWeight();
    return {$urandom,(($urandom%100)<20)?1'b0:1'b1};
endfunction

module top;

    integer RAND;
    integer i;

    initial
    begin
        for( i = 0; i < 20; i=i+1 )
        begin
            RAND = getWeight();
            $display("RAND : %0d", RAND);
        end
    end

endmodule

    function reg [31:0] getUs();
    return {$urandom>>1};
endfunction

module top;

    integer RAND;

    initial
    begin
        RAND = getUs();
        $display("RAND : %0d", RAND);
    end

endmodule
    Locked Solution 
    function reg [63:0] get64();
    return {$urandom,$urandom};
endfunction

module top;

    reg [63:0] RAND;

    initial
    begin
        RAND = getUs();
        $display("RAND : %0d", RAND);
    end

endmodule