//////////////////////////////////////////////////////////////
//	4-bit loadable up-down counter			//////
//////////////////////////////////////////////////////////////

module counter(clk, rst, data, updown, load, data_out);
	
	input clk, rst, load;
	input updown;
	input [3:0] data;

	output reg [3:0] data_out;


	always@(posedge clk)
	begin
		if(rst)
			data_out <= 4'b0;
		else if(load)
			data_out <= data;
		else
			data_out <= ((updown)?(data_out + 1'b1):(data_out -1'b1));
	end

endmodule