module top (
	input  clk,
	output [3:0] led,
	inout out_a,
	output [1:0] out_b,
	output signal_p,
	output signal_n
);

	wire LD6, LD7, LD8, LD9;
	wire inter_wire, inter_wire_2;
	localparam BITS = 1;
	localparam LOG2DELAY = 25;

	reg [BITS+LOG2DELAY-1:0] counter = 0;

	always @(posedge clk) begin
		counter <= counter + 1;
	end
	assign led[1] = inter_wire;
	assign inter_wire = inter_wire_2;
	assign {LD9, LD8, LD7, LD6} = counter >> LOG2DELAY;
	OBUFTDS OBUFTDS_2(
		.I(LD6),
		.O(signal_p),
		.OB(signal_n),
		.T(1'b1)
	);
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_6(.I(LD6), .O(led[0]));
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_7(.I(LD7), .O(inter_wire_2));
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_OUT(.I(LD7), .O(out_a));
	bottom bottom_inst(.I(LD8), .O(led[2]), .OB(out_b));
	bottom_intermediate bottom_intermediate_inst(.I(LD9), .O(led[3]));
endmodule

module bottom_intermediate (
	input I,
	output O
);
	wire bottom_intermediate_wire;
	assign O = bottom_intermediate_wire;
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_8(.I(I), .O(bottom_intermediate_wire));
endmodule

module bottom (
	input I,
	output [1:0] OB,
	output O
);
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_9(.I(I), .O(O));
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_10(.I(I), .O(OB[0]));
	OBUF #(
		.IOSTANDARD("LVCMOS33"),
		.SLEW("SLOW")
	) OBUF_11(.I(I), .O(OB[1]));
endmodule