Binary to gray

Theory:

A binary to Gray code converter is a tool or circuit that transforms a binary number into its equivalent Gray code representation, where only one bit changes between consecutive numbers.  

Block diagram:

Truth table:

Verilog code:

module binary_gray1(binary_in2,binary_in1,binary_in0,

     gray_out2,gray_out1,gray_out0);

    input binary_in2,binary_in1,binary_in0;

    output gray_out2,gray_out1,gray_out0;

    assign gray_out2=binary_in2;

assign gray_out1=(binary_in1)^(binary_in2);

assign gray_out0=(binary_in1)^(binary_in0);

endmodule

Test bench: 

module binary_gray1_tb;

reg binary_in2;

reg binary_in1;

reg binary_in0;

wire gray_out2;

wire gray_out1;

wire gray_out0;

binary_gray1 uut (

.binary_in2(binary_in2), 

.binary_in1(binary_in1), 

.binary_in0(binary_in0), 

.gray_out2(gray_out2), 

.gray_out1(gray_out1), 

.gray_out0(gray_out0)

);

initial begin

binary_in2 = 0;

binary_in1 = 0;

binary_in0 = 0;

#100;

        binary_in2 = 0;

binary_in1 = 0;

binary_in0 = 1;

#100;

binary_in2 = 0;

binary_in1 = 1;

binary_in0 = 0;

#100;

binary_in2 = 0;

binary_in1 = 1;

binary_in0 = 1;

#100;

binary_in2 = 1;

binary_in1 = 0;

binary_in0 = 0;

#100;

binary_in2 = 1;

binary_in1 = 0;

binary_in0 = 1;

#100;

binary_in2 = 1;

binary_in1 = 1;

binary_in0 = 0;

#100;

binary_in2 = 1;

binary_in1 = 1;

binary_in0 = 1;

#100;

end

 endmodule

Output:

RTL schematic: