module syswb(VGA_R, VGA_G, VGA_B, VGA_HS, VGA_VS, CLOCK_27);
	output reg[3:0] VGA_R;
	output reg[3:0] VGA_G;
	output reg[3:0] VGA_B;
	reg [9:0] HS_count;

	output reg VGA_VS;
	output reg VGA_HS;
	input [1:0] CLOCK_27;
	parameter FRONT_PORCH_A = 16;
	parameter SYNC_PULSE_B = 96;
	parameter BACK_PORCH_C = 48;
	parameter ACTIVE_VIDEO_D = 640;

	parameter V_FRONT_PORCH_A = 10;
	parameter V_SYNC_PULSE_B = 2;
	parameter V_BACK_PORCH_C = 33;
	parameter V_ACTIVE_VIDEO_D = 480;

	wire VGA_CLK;
	    clock u0 (
        .clk_clk       (CLOCK_27[1]),       //     clk.clk
        .reset_reset_n (0), //   reset.reset_n
        .clk_out_clk   (VGA_CLK),   // clk_out.clk
        .clk_in_clk    (CLOCK_27[1]),    //  clk_in.clk
        .clk_res_reset (0)  // clk_res.reset
    );

	 always @(*)
		 begin
		 /*
			if(HS_count>=BACK_PORCH_C  + 320+ SYNC_PULSE_B &&
		  HS_count <= BACK_PORCH_C + SYNC_PULSE_B + ACTIVE_VIDEO_D &&
		  VS_count >= V_BACK_PORCH_C + V_SYNC_PULSE_B &&
		  VS_count<= V_BACK_PORCH_C -240+ V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
				begin
					VGA_R = 4'd15;
					VGA_B = 0;
					VGA_G = 0;
				end
			else if(HS_count>=BACK_PORCH_C + SYNC_PULSE_B &&
		  HS_count <= BACK_PORCH_C - 320 + SYNC_PULSE_B + ACTIVE_VIDEO_D &&
		  VS_count >= V_BACK_PORCH_C + V_SYNC_PULSE_B &&
		  VS_count<= V_BACK_PORCH_C - 240 + V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
				begin
					VGA_R = 0;
					VGA_B = 4'd15;
					VGA_G = 0;
				end
			else if(HS_count>=BACK_PORCH_C + SYNC_PULSE_B &&
			HS_count <= BACK_PORCH_C -320+ SYNC_PULSE_B + ACTIVE_VIDEO_D &&
			VS_count >= V_BACK_PORCH_C + 240 + V_SYNC_PULSE_B &&
			VS_count<= V_BACK_PORCH_C+ V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
				begin
					VGA_R = 0;
					VGA_B = 0;
					VGA_G = 4'd15;
				end
				*/
			if(HS_count>=BACK_PORCH_C + SYNC_PULSE_B &&
			HS_count <= BACK_PORCH_C -320+ SYNC_PULSE_B + ACTIVE_VIDEO_D &&
			VS_count >= V_BACK_PORCH_C + 240 + V_SYNC_PULSE_B &&
			VS_count<= V_BACK_PORCH_C+ V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
				begin
					VGA_R = 4'd15;
					VGA_B = 0;
					VGA_G = 0;
				end


		 end

	/*
	assign VGA_R =(HS_count>=BACK_PORCH_C + 320 + SYNC_PULSE_B &&
	  HS_count <= BACK_PORCH_C + SYNC_PULSE_B + ACTIVE_VIDEO_D &&
	  VS_count >= V_BACK_PORCH_C + V_SYNC_PULSE_B &&
	  VS_count<= V_BACK_PORCH_C -240+ V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
		  ? 4'd15 : 0;

	assign VGA_B =(HS_count>=BACK_PORCH_C + SYNC_PULSE_B &&
	  HS_count <= BACK_PORCH_C -320+ SYNC_PULSE_B + ACTIVE_VIDEO_D &&
	  VS_count >= V_BACK_PORCH_C + V_SYNC_PULSE_B &&
	  VS_count<= V_BACK_PORCH_C - 240 + V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
		  ? 4'd15 : 0;

	assign VGA_G =(HS_count>=BACK_PORCH_C + SYNC_PULSE_B &&
		HS_count <= BACK_PORCH_C -320+ SYNC_PULSE_B + ACTIVE_VIDEO_D &&
		VS_count >= V_BACK_PORCH_C + 240 + V_SYNC_PULSE_B &&
		VS_count<= V_BACK_PORCH_C+ V_SYNC_PULSE_B + V_ACTIVE_VIDEO_D)
			? 4'd15 : 0;
	*/


	//HS signal generator
	always @(posedge VGA_CLK)
		begin
		  if (HS_count < FRONT_PORCH_A + SYNC_PULSE_B +
				BACK_PORCH_C + ACTIVE_VIDEO_D)
			  HS_count <= HS_count + 1;
		  else
			  HS_count <= 0;

		  if (HS_count < SYNC_PULSE_B)
			  VGA_HS <= 0;
		  else
			  VGA_HS <= 1;
		end
	reg [9:0] VS_count;
	//VS signal generator
	always @(posedge VGA_CLK)
		begin
		  if (HS_count==0)
		  begin
			  if (VS_count < V_FRONT_PORCH_A + V_SYNC_PULSE_B
						+ V_BACK_PORCH_C + V_ACTIVE_VIDEO_D)
				 VS_count <= VS_count +1;
			  else
				 VS_count <= 0;

			  if (VS_count < V_SYNC_PULSE_B)
				VGA_VS <= 0;
			  else
				VGA_VS <=1;
		  end
		end
endmodule