`timescale 1ns / 1ns

module rs232_tf (clk, reset,displayed,sdata,received);
	
	input clk;  
	input reset;
	input displayed;	//flag value to initiate end of handshake
	
	output received;
	output sdata;
	reg sdata;    // holds output to converted from serial to parallel
	reg received;       //flag value initiating handshake
	
	reg [3:0] bitCount;  // Count of number bits sent
	reg [7:0] char;
	reg [2:0] lettercounter;
	
	// Keep the state machine from starting until the LCD has
	// had a chance to reset.  Actually, we only need to wait
	// long enough so that the LCD is finished reseting before the
	// first write signal
	reg 	     hold;
	initial begin
			hold = 1;
			#120 hold = 0;		//!!!!!WARNING!!!! ASSUMES 10 NS CLOCK CYCLE ADJUST ACCORDINGLY
		end
	
	// Character generator (generates "Good Job" "'h47'h6f'h6f'h64'h4a'h6f'h62")  	
	always @(posedge clk) begin
			if (reset) begin
					received <= 0;
					sdata <= 1;	
					char <= 8'h47; 
					lettercounter <= 0;
				end
			else if (!received && !displayed) begin
					// setup state machine
					received <= 1;
					bitCount <= 0;
					sdata <= 0;	   //output start bit
				end
			else if (received && !displayed && (bitCount < 8)) begin
					// output the next value in the buffer
					sdata <= char[bitCount];
					bitCount <= bitCount + 1;
				end
			else if (received && !displayed && (bitCount >= 8)) begin
					// if done shifting, reset shifting, set done and keep output high
					sdata <= 1;
				end
			else if (received & displayed) begin
					// reset done once handshake completes in other always block or if nothing is happening
					received <= 0; 
					
					// move to next letter
					case (lettercounter)
					0: begin char <= 8'h6f; lettercounter <= lettercounter + 1; end //o
					1: begin char <= 8'h6f; lettercounter <= lettercounter + 1; end	//o
					2: begin char <= 8'h64; lettercounter <= lettercounter + 1; end	//d
					3: begin char <= 8'h4a; lettercounter <= lettercounter + 1; end	//J
					4: begin char <= 8'h6f; lettercounter <= lettercounter + 1; end	//o
					5: begin char <= 8'h62; lettercounter <= lettercounter + 1; end	//b
					6: begin char <= 8'h47; lettercounter <= 0; end					//G
					endcase
					
				end
		end  		
	
endmodule