Gray to Binary Code Converter

Gray code has its own applications and we have seen how binary code is converted to the Gray code in the previous post Binary to Gray Code Converter.

Let’s Gray code to Binary code implementation in Verilog.

Truth Table

By solving using K-map technique, a simple combinational circuit turned out as

Gray to Binary Code Converter Verilog code

module g2b_converter #(parameter WIDTH=4) (input [WIDTH-1:0] gray, output [WIDTH-1:0] binary);
  /*
  assign binary[0] = gray[3] ^ gray[2] ^ gray[1] ^ gray[0];
  assign binary[1] = gray[3] ^ gray[2] ^ gray[1];
  assign binary[2] = gray[3] ^ gray[2];
  assign binary[3] = gray[3];
  */
  // OR
  genvar i;
  generate
    for(i=0;i<WIDTH;i++) begin
      assign binary[i] = ^(gray >> i);
    end
  endgenerate
endmodule

Testbench Code

module TB;
  reg [3:0] binary, gray;
  g2b_converter g2b(gray, binary);
  
  initial begin
    $monitor("Gray = %b --> Binary = %b", gray, binary);
    gray = 4'b1110; #1;
    gray = 4'b0100; #1;
    gray = 4'b0111; #1;
    gray = 4'b1010; #1;
    gray = 4'b1000;
  end
endmodule

Output:

Gray = 1110 --> Binary = 1011
Gray = 0100 --> Binary = 0111
Gray = 0111 --> Binary = 0101
Gray = 1010 --> Binary = 1100
Gray = 1000 --> Binary = 1111

Verilog Codes