Subversion Repositories wb_lcd

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  system.v                                                    ////
////                                                              ////
////  This file is part of:                                       ////
////  WISHBONE/MEM MAPPED CONTROLLER FOR LCD CHARACTER DISPLAYS   ////
////  http://www.opencores.org/projects/wb_lcd/                   ////
////                                                              ////
////  Description                                                 ////
////   - Memory mapped controller testbench implementation for    ////
////     Spartan 3E Starter Kit (XC3S500E) board from Digilent.   ////
////  To Do:                                                      ////
////   - nothing really                                           ////
////                                                              ////
////  Author(s):                                                  ////
////   - José Ignacio Villar, jose@dte.us.es , jvillar@gmail.com  ////
////      - Grupo ID2 http://www.dte.us.es/id2/                   ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2009 José Ignacio Villar - jvillar@gmail.com   ////
////                                                              ////
//// This source file may be used and distributed without         ////
//// restriction provided that this copyright statement is not    ////
//// removed from the file and that any derivative work contains  ////
//// the original copyright notice and the associated disclaimer. ////
////                                                              ////
//// This source file is free software; you can redistribute it   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// Public License as published by the Free Software Foundation; ////
//// either version 3 of the License, or (at your option) any     ////
//// later version.                                               ////
////                                                              ////
//// This source is distributed in the hope that it will be       ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
//// PURPOSE.  See the GNU Lesser General Public License for more ////
//// details.                                                     ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// from http://www.gnu.org/licenses/lgpl.txt                    ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
 
`include "lcd_defines.v"
 
module system(
	input clk,
	input reset,
 
	input  [2:0] rot,
 
	output [3:0] SF_D,
	output LCD_E,
	output LCD_RS,
	output LCD_RW,
	output SF_CE0,
 
	output reg [7:0] led
	);
 
//----------------------------------------------------------------------------
// rotary decoder
//----------------------------------------------------------------------------
wire rot_btn;
wire rot_event;
wire rot_left;
 
rotary rotdec0 (
	.clk(       clk        ),
	.reset(     reset      ),
	.rot(       rot        ),
	// output
	.rot_btn(   rot_btn    ),
	.rot_event( rot_event  ),
	.rot_left(  rot_left   )
);
 
//----------------------------------------------------------------------------
// LCD Display
//----------------------------------------------------------------------------
 
 
wire busy;
reg repaint = 0;
reg [`DAT_RNG]  dat = 8'b00100000;
reg [`ADDR_RNG] addr = 0;
reg we = 0;
 
lcd lcd(
	.clk		( clk ),
	.reset	( reset),
 
	.dat		( dat ),
	.addr		( addr ),
	.we		( we ),
	.repaint	( repaint ),
 
	.busy		( busy ),
	.SF_D		( SF_D ),
	.LCD_E	( LCD_E ),
	.LCD_RS	( LCD_RS ),
	.LCD_RW	( LCD_RW )
 
	);
 
//----------------------------------------------------------------------------
// Behavioural description
//----------------------------------------------------------------------------
assign SF_CE0 = 1'b1; // disable intel strataflash
 
// Handles "start displaying character" shift
reg [`DAT_RNG]  start_dat = 8'b00100000;
 
 
// Handles transfers to the display
integer i = 0;
always @(posedge clk) 
begin
	if(reset) begin
		i <= 0;
		repaint <= 0;
 
		we <= 1;
		addr <= 0;
		dat <= start_dat;
 
		led <= 8'b00100000;
		start_dat <= 8'b00100000;
	end if (i < 104) begin
		i <= i + 1;
		repaint <= 0;
 
		we <= 1'b1;
		addr <= addr + 1;
		dat <= dat + 1;
	end if (i == 104 && !busy) begin
		i <= i + 1;
		repaint <= 1;
		we <= 1'b0;
 
	end if (i == 105) begin
		i <= i + 1;
		repaint <= 0;
		we <= 1'b0;
	end else if (rot_event && rot_left && !busy) begin
		i <= 0;
		led <= led - 1;
		start_dat <= start_dat - 1;
 
		addr <= 0;
		repaint <= 0;
		we <= 1'b1;
		dat <= start_dat - 1;
	end else if (rot_event && !busy) begin
		i <= 0;
		led <= led + 1;
		start_dat <= start_dat + 1;	
 
		addr <= 0;
		repaint <= 0;
		we <= 1'b1;
		dat <= start_dat + 1;
	end
end
 
 
endmodule