module error_correction(
	input	[6:0]IN,
	output	[6:0]OUT
);

	wire	s1,s2,s3;

	assign	s1 = IN[6]^IN[5]^IN[4]^IN[2];
	assign	s2 = IN[6]^IN[5]^IN[3]^IN[1];
	assign	s3 = IN[6]^IN[4]^IN[3]^IN[0];
	assign	OUT= COR(IN,{s1,s2,s3});

	function [6:0]COR;
		input	[6:0]in;
		input	[2:0]q;

		case(q)
			3'b111:COR = {~in[6],in[5:0]};
			3'b110:COR = {in[6],~in[5],in[4:0]};
			3'b101:COR = {in[6:5],~in[4],in[3:0]};
			3'b011:COR = {in[6:4],~in[3],in[2:0]};
			3'b100:COR = {in[6:3],~in[2],in[1:0]};
			3'b010:COR = {in[6:2],~in[1],in[0]};
			3'b001:COR = {in[6:1],~in[0]};
			3'b000:COR = in;
		endcase
	endfunction

endmodule