module part4(SW,KEY,CLOCK_50,LEDR);
	input CLOCK_50; //50MHz internal clock
	input [2:0] SW; //inputs for characters A-H
	input [1:0] KEY; //KEY[1] is button that loads the letter
					 //KEY[0] is asynchronous reset
	output reg [0:0] LEDR; //morse code output
	parameter A = 0, B = 1, C = 2, D = 3, E = 4, F = 5, G = 6, H = 7;
	parameter patA = 4'b0001, patB = 4'b1110, patC = 4'b1010, patD = 4'b0110,
			patE = 4'b0001, patF = 4'b1011, patG = 4'b0100, patH = 4'b1111;
	
	reg [3:0]letterSize; //length of w
	reg [3:0]w; //input into the letter symbols shift register
				//0 is dot, 1 is dash
	
	wire newPattern;
	
	wire clk;
	assign clk = ~KEY[1];
	wire resetn;
	assign resetn = KEY[0];

	always@(posedge clk)
	begin
		case(SW)
			A:  begin 	letterSize = 2;
						w = patA; end
				
			B:  begin 	letterSize = 4;
						w = patB; end
			
			C:  begin 	letterSize = 4;
						w = patC; end
				
			D:  begin 	letterSize = 3;
						w = patD; end
			
			E:  begin	letterSize = 1;
						w = patE; end
				
			F:  begin 	letterSize = 4;
						w = patF; end
				
			G:  begin	letterSize = 3;
						w = patG; end
				
			H:  begin	letterSize = 4;
						w = patH; end
		endcase

	end	

	parameter Default = 0, Dot = 1, Dash = 2;
	reg [1:0]nextState = 2'b00;
	reg restPeriod = 0;
	integer k = 0;
	reg [2:0]count = 4;
	
	always @(posedge CLOCK_50) //print morsecode
	begin
		k = k + 1;
		
		if (clk)
		count = 0;
	
			if (!restPeriod)
			begin
				if (k == 25000000) //0.5 sec
				begin
					restPeriod = (count < letterSize)? ~restPeriod: restPeriod; //turns restPeriod 1
					case (count)
						A:	if (w[0]) nextState = Dot;
							else nextState = Dash;
						B:	if(w[1]) nextState = Dot;
							else nextState = Dash;
						C:	if(w[2]) nextState = Dot;
							else nextState = Dash;
						D:	if(w[3]) nextState = Dot;
					endcase
					k = 0;
				end
			end	
				
				
			else if (restPeriod & (nextState == Dash))
			begin
				LEDR[0] = (count < letterSize)? 1: 0;
				if (k == 75000000) //1.5sec
				begin
				
					LEDR[0] = 0;
					count = (count < letterSize)? (count +1):count;
					k = 0;
					restPeriod = ~restPeriod;
				end
			
			end
			
			else if (restPeriod & (nextState == Dot))
			begin
				LEDR[0] = (count < letterSize)? 1: 0;
				if (k == 12500000) //0.25 sec
				begin
				
					LEDR[0] = 0;
					count = (count < letterSize)? (count +1) :count;
					k = 0;
					restPeriod = ~restPeriod;
				end
			end
	end
endmodule

module Reg (D, Q, clk, resetn);
	input clk;
	input [1:0]D;
	input resetn;
	output reg [1:0]Q;

	always @ (posedge clk)
		if (!resetn)
			Q <= 0;
		else
			Q <= D;
endmodule