// --------------------------------------------------------------------
// Copyright (c) 2005 by Terasic Technologies Inc. 
// --------------------------------------------------------------------
//
// Major Functions:	DE2 LTM module Timing control and color pattern 
//					generator
// 
// --------------------------------------------------------------------
// Revision History :
// --------------------------------------------------------------------
//   Ver  :| Author            		:| Mod. Date :| Changes Made:
//   V1.0 :| Johnny Fan				:| 07/06/30  :| Initial Revision
// --------------------------------------------------------------------
module lcd_timing_controller		(
						iCLK, 				// LCD display clock
						iRST_n, 			// systen reset
						//LCD SIDE
						iRed,
						iGreen,
						iBlue,
						oHD,				// LCD Horizontal sync 
						oVD,				// LCD Vertical sync 	
						oDEN,				// LCD Data Enable
						oLCD_R,				// LCD Red color data 
						oLCD_G,             // LCD Green color data  
						oLCD_B,             // LCD Blue color data  
						iDISPLAY_MODE
						);
//============================================================================
// PARAMETER declarations
//============================================================================
parameter H_LINE = 1056;
parameter V_LINE = 525;
parameter Hsync_Blank = 216;
parameter Hsync_Front_Porch = 40;
parameter Vertical_Back_Porch = 35;
parameter Vertical_Front_Porch = 10;
//===========================================================================
// PORT declarations
//===========================================================================
input			iCLK;   
input			iRST_n;
input	[7:0]	iRed;
input	[7:0]	iGreen;
input	[7:0]	iBlue;
output	[7:0]	oLCD_R;		
output  [7:0]	oLCD_G;
output  [7:0]	oLCD_B;
output			oHD;
output			oVD;
output			oDEN;
input	[1:0]	iDISPLAY_MODE;	
//=============================================================================
// REG/WIRE declarations
//=============================================================================
reg		[10:0]  x_cnt;  //  x_cnt  >> 11 bits
reg		[9:0]	y_cnt; 
wire	[7:0]	mred;
wire	[7:0]	mgreen;
wire	[7:0]	mblue; 
wire			display_area;
reg				mhd;
reg				mvd;
reg				mden;
reg				oHD;
reg				oVD;
reg				oDEN;
reg		[7:0]	oLCD_R;
reg		[7:0]	oLCD_G;	
reg		[7:0]	oLCD_B;	
wire	[1:0]	msel;	
reg		[7:0]	red_1;
reg 	[7:0]	green_1;
reg 	[7:0]	blue_1;
reg 	[7:0]	graycnt;
reg		[7:0]	pattern_data;

//=============================================================================
// Structural coding
//=============================================================================

					
// This signal indicate the lcd(LTM) display area .
assign	display_area = ((x_cnt>(Hsync_Blank-1)&& //x_cnt > 215
						(x_cnt<(H_LINE-Hsync_Front_Porch))&& //x_cnt < 1016
						(y_cnt>(Vertical_Back_Porch-1))&& // y_cnt > 34
						(y_cnt<(V_LINE - Vertical_Front_Porch))//y_cnt < 515
						))  ? 1'b1 : 1'b0;


///////////////////////// x  y counter  and lcd hd generator //////////////////

always@(posedge iCLK or negedge iRST_n)
	begin
		if (!iRST_n)
		begin
			x_cnt <= 11'd0;	
			mhd  <= 1'd0;  	
		end	
		else if (x_cnt == (H_LINE-1))
		begin
			x_cnt <= 11'd0;
			mhd  <= 1'd0;
		end	   
		else
		begin
			x_cnt <= x_cnt + 11'd1;
			mhd  <= 1'd1;
		end	
	end

always@(posedge iCLK or negedge iRST_n)
	begin
		if (!iRST_n)
			y_cnt <= 10'd0;
		else if (x_cnt == (H_LINE-1))
		begin
			if (y_cnt == (V_LINE-1))
				y_cnt <= 10'd0;
			else
				y_cnt <= y_cnt + 10'd1;	
		end
	end
	
////////////////////////////// touch panel timing //////////////////

always@(posedge iCLK  or negedge iRST_n)
	begin
		if (!iRST_n)
			mvd  <= 1'b1;
		else if (y_cnt == 10'd0)
			mvd  <= 1'b0;
		else
			mvd  <= 1'b1;
	end			

always@(posedge iCLK  or negedge iRST_n)
	begin
		if (!iRST_n)
			mden  <= 1'b0;
		else if (display_area)
			mden  <= 1'b1;
		else
			mden  <= 1'b0;
	end			



assign mred    = iRed;

assign mgreen  = iGreen;
				 
assign mblue   = iBlue;


always@(posedge iCLK or negedge iRST_n)
	begin
		if (!iRST_n)
			begin
				oHD	<= 1'd0;
				oVD	<= 1'd0;
				oDEN <= 1'd0;
				oLCD_R <= 8'd0;
				oLCD_G <= 8'd0;
				oLCD_B <= 8'd0;
			end
		else
			begin
				oHD	<= mhd;
				oVD	<= mvd;
				oDEN <= display_area;
				oLCD_R <= mred;
				oLCD_G <= mgreen;
				oLCD_B <= mblue;
			end		
	end
						
endmodule