///////////////////////////////////////////////////////////////////////////////
//
// 6.111 FPGA Labkit -- Lab 1 Template
//
// Created: January 12, 2006
// Author: Nathan Ickes (orginal labkit template and display module)
// 	Additional changes made by Kyeong-Jae Lee
//
// Purpose: Provides a template for a simple 7-segment display driver using
//	the labkit's slide switches and the LED dot-matrix display.
//
// Usage:   Implement your own 7-segment decoder ('segment_decoder').
//	    Use switch[3:0] as the 4-bit input, and the LED display should show the
//	    correct digit.
//
// Structure:
//	lab1		: top-level labkit module
//	display		: driver for labkit's LED display
//	dot_converter	: conversion module for 7-segment to LED dot-matrix
//	segment_decoder	: conversion module for 4-bit input to 7-segment display (NOT INCLUDED)
//
///////////////////////////////////////////////////////////////////////////////







///////////////////////////////////////////////////////////////////////////////
//
// 6.111 FPGA Labkit -- Template Toplevel Module
//
// For Labkit Revision 004
//
//
// Created: October 31, 2004, from revision 003 file
// Author: Nathan Ickes
//
///////////////////////////////////////////////////////////////////////////////
//
// CHANGES FOR BOARD REVISION 004
//
// 1) Added signals for logic analyzer pods 2-4.
// 2) Expanded "tv_in_ycrcb" to 20 bits.
// 3) Renamed "tv_out_data" to "tv_out_i2c_data" and "tv_out_sclk" to
//    "tv_out_i2c_clock".
// 4) Reversed disp_data_in and disp_data_out signals, so that "out" is an
//    output of the FPGA, and "in" is an input.
//
// CHANGES FOR BOARD REVISION 003
//
// 1) Combined flash chip enables into a single signal, flash_ce_b.
//
// CHANGES FOR BOARD REVISION 002
//
// 1) Added SRAM clock feedback path input and output
// 2) Renamed "mousedata" to "mouse_data"
// 3) Renamed some ZBT memory signals. Parity bits are now incorporated into 
//    the data bus, and the byte write enables have been combined into the
//    4-bit ram#_bwe_b bus.
// 4) Removed the "systemace_clock" net, since the SystemACE clock is now
//    hardwired on the PCB to the oscillator.
//
///////////////////////////////////////////////////////////////////////////////
//
// Complete change history (including bug fixes)
//
// 2005-Sep-09: Added missing default assignments to "ac97_sdata_out",
//              "disp_data_out", "analyzer[2-3]_clock" and
//              "analyzer[2-3]_data".
//
// 2005-Jan-23: Reduced flash address bus to 24 bits, to match 128Mb devices
//              actually populated on the boards. (The boards support up to
//              256Mb devices, with 25 address lines.)
//
// 2004-Oct-31: Adapted to new revision 004 board.
//
// 2004-May-01: Changed "disp_data_in" to be an output, and gave it a default
//              value. (Previous versions of this file declared this port to
//              be an input.)
//
// 2004-Apr-29: Reduced SRAM address busses to 19 bits, to match 18Mb devices
//              actually populated on the boards. (The boards support up to
//              72Mb devices, with 21 address lines.)
//
// 2004-Apr-29: Change history started
//
///////////////////////////////////////////////////////////////////////////////

module lab1 (beep, audio_reset_b, ac97_sdata_out, ac97_sdata_in, ac97_synch,
	       ac97_bit_clock,
	       
	       vga_out_red, vga_out_green, vga_out_blue, vga_out_sync_b,
	       vga_out_blank_b, vga_out_pixel_clock, vga_out_hsync,
	       vga_out_vsync,

	       tv_out_ycrcb, tv_out_reset_b, tv_out_clock, tv_out_i2c_clock,
	       tv_out_i2c_data, tv_out_pal_ntsc, tv_out_hsync_b,
	       tv_out_vsync_b, tv_out_blank_b, tv_out_subcar_reset,

	       tv_in_ycrcb, tv_in_data_valid, tv_in_line_clock1,
	       tv_in_line_clock2, tv_in_aef, tv_in_hff, tv_in_aff,
	       tv_in_i2c_clock, tv_in_i2c_data, tv_in_fifo_read,
	       tv_in_fifo_clock, tv_in_iso, tv_in_reset_b, tv_in_clock,

	       ram0_data, ram0_address, ram0_adv_ld, ram0_clk, ram0_cen_b,
	       ram0_ce_b, ram0_oe_b, ram0_we_b, ram0_bwe_b, 

	       ram1_data, ram1_address, ram1_adv_ld, ram1_clk, ram1_cen_b,
	       ram1_ce_b, ram1_oe_b, ram1_we_b, ram1_bwe_b,

	       clock_feedback_out, clock_feedback_in,

	       flash_data, flash_address, flash_ce_b, flash_oe_b, flash_we_b,
	       flash_reset_b, flash_sts, flash_byte_b,

	       rs232_txd, rs232_rxd, rs232_rts, rs232_cts,

	       mouse_clock, mouse_data, keyboard_clock, keyboard_data,

	       clock_27mhz, clock1, clock2,

	       disp_blank, disp_data_out, disp_clock, disp_rs, disp_ce_b,
	       disp_reset_b, disp_data_in,

	       button0, button1, button2, button3, button_enter, button_right,
	       button_left, button_down, button_up,

	       switch,

	       led,
	       
	       user1, user2, user3, user4,
	       
	       daughtercard,

	       systemace_data, systemace_address, systemace_ce_b,
	       systemace_we_b, systemace_oe_b, systemace_irq, systemace_mpbrdy,
	       
	       analyzer1_data, analyzer1_clock,
 	       analyzer2_data, analyzer2_clock,
 	       analyzer3_data, analyzer3_clock,
 	       analyzer4_data, analyzer4_clock);

   output beep, audio_reset_b, ac97_synch, ac97_sdata_out;
   input  ac97_bit_clock, ac97_sdata_in;
   
   output [7:0] vga_out_red, vga_out_green, vga_out_blue;
   output vga_out_sync_b, vga_out_blank_b, vga_out_pixel_clock,
	  vga_out_hsync, vga_out_vsync;

   output [9:0] tv_out_ycrcb;
   output tv_out_reset_b, tv_out_clock, tv_out_i2c_clock, tv_out_i2c_data,
	  tv_out_pal_ntsc, tv_out_hsync_b, tv_out_vsync_b, tv_out_blank_b,
	  tv_out_subcar_reset;
   
   input  [19:0] tv_in_ycrcb;
   input  tv_in_data_valid, tv_in_line_clock1, tv_in_line_clock2, tv_in_aef,
	  tv_in_hff, tv_in_aff;
   output tv_in_i2c_clock, tv_in_fifo_read, tv_in_fifo_clock, tv_in_iso,
	  tv_in_reset_b, tv_in_clock;
   inout  tv_in_i2c_data;
        
   inout  [35:0] ram0_data;
   output [18:0] ram0_address;
   output ram0_adv_ld, ram0_clk, ram0_cen_b, ram0_ce_b, ram0_oe_b, ram0_we_b;
   output [3:0] ram0_bwe_b;
   
   inout  [35:0] ram1_data;
   output [18:0] ram1_address;
   output ram1_adv_ld, ram1_clk, ram1_cen_b, ram1_ce_b, ram1_oe_b, ram1_we_b;
   output [3:0] ram1_bwe_b;

   input  clock_feedback_in;
   output clock_feedback_out;
   
   inout  [15:0] flash_data;
   output [23:0] flash_address;
   output flash_ce_b, flash_oe_b, flash_we_b, flash_reset_b, flash_byte_b;
   input  flash_sts;
   
   output rs232_txd, rs232_rts;
   input  rs232_rxd, rs232_cts;

   input  mouse_clock, mouse_data, keyboard_clock, keyboard_data;

   input  clock_27mhz, clock1, clock2;

   output disp_blank, disp_clock, disp_rs, disp_ce_b, disp_reset_b;  
   input  disp_data_in;
   output  disp_data_out;
   
   input  button0, button1, button2, button3, button_enter, button_right,
	  button_left, button_down, button_up;
   input  [7:0] switch;
   output [7:0] led;

   inout [31:0] user1, user2, user3, user4;
   
   inout [43:0] daughtercard;

   inout  [15:0] systemace_data;
   output [6:0]  systemace_address;
   output systemace_ce_b, systemace_we_b, systemace_oe_b;
   input  systemace_irq, systemace_mpbrdy;

   output [15:0] analyzer1_data, analyzer2_data, analyzer3_data, 
		 analyzer4_data;
   output analyzer1_clock, analyzer2_clock, analyzer3_clock, analyzer4_clock;

   ////////////////////////////////////////////////////////////////////////////
   //
   // I/O Assignments
   //
   ////////////////////////////////////////////////////////////////////////////
   
   // Audio Input and Output
   assign beep= 1'b0;
   assign audio_reset_b = 1'b0;
   assign ac97_synch = 1'b0;
   assign ac97_sdata_out = 1'b0;
   // ac97_sdata_in is an input

   // VGA Output
   assign vga_out_red = 10'h0;
   assign vga_out_green = 10'h0;
   assign vga_out_blue = 10'h0;
   assign vga_out_sync_b = 1'b1;
   assign vga_out_blank_b = 1'b1;
   assign vga_out_pixel_clock = 1'b0;
   assign vga_out_hsync = 1'b0;
   assign vga_out_vsync = 1'b0;

   // Video Output
   assign tv_out_ycrcb = 10'h0;
   assign tv_out_reset_b = 1'b0;
   assign tv_out_clock = 1'b0;
   assign tv_out_i2c_clock = 1'b0;
   assign tv_out_i2c_data = 1'b0;
   assign tv_out_pal_ntsc = 1'b0;
   assign tv_out_hsync_b = 1'b1;
   assign tv_out_vsync_b = 1'b1;
   assign tv_out_blank_b = 1'b1;
   assign tv_out_subcar_reset = 1'b0;
   
   // Video Input
   assign tv_in_i2c_clock = 1'b0;
   assign tv_in_fifo_read = 1'b0;
   assign tv_in_fifo_clock = 1'b0;
   assign tv_in_iso = 1'b0;
   assign tv_in_reset_b = 1'b0;
   assign tv_in_clock = 1'b0;
   assign tv_in_i2c_data = 1'bZ;
   // tv_in_ycrcb, tv_in_data_valid, tv_in_line_clock1, tv_in_line_clock2, 
   // tv_in_aef, tv_in_hff, and tv_in_aff are inputs
   
   // SRAMs
   assign ram0_data = 36'hZ;
   assign ram0_address = 19'h0;
   assign ram0_adv_ld = 1'b0;
   assign ram0_clk = 1'b0;
   assign ram0_cen_b = 1'b1;
   assign ram0_ce_b = 1'b1;
   assign ram0_oe_b = 1'b1;
   assign ram0_we_b = 1'b1;
   assign ram0_bwe_b = 4'hF;
   assign ram1_data = 36'hZ; 
   assign ram1_address = 19'h0;
   assign ram1_adv_ld = 1'b0;
   assign ram1_clk = 1'b0;
   assign ram1_cen_b = 1'b1;
   assign ram1_ce_b = 1'b1;
   assign ram1_oe_b = 1'b1;
   assign ram1_we_b = 1'b1;
   assign ram1_bwe_b = 4'hF;
   assign clock_feedback_out = 1'b0;
   // clock_feedback_in is an input
   
   // Flash ROM
   assign flash_data = 16'hZ;
   assign flash_address = 24'h0;
   assign flash_ce_b = 1'b1;
   assign flash_oe_b = 1'b1;
   assign flash_we_b = 1'b1;
   assign flash_reset_b = 1'b0;
   assign flash_byte_b = 1'b1;
   // flash_sts is an input

   // RS-232 Interface
   assign rs232_txd = 1'b1;
   assign rs232_rts = 1'b1;
   // rs232_rxd and rs232_cts are inputs

   // PS/2 Ports
   // mouse_clock, mouse_data, keyboard_clock, and keyboard_data are inputs

   // LED Displays
/*   assign disp_blank = 1'b1;
   assign disp_clock = 1'b0;
   assign disp_rs = 1'b0;
   assign disp_ce_b = 1'b1;
   assign disp_reset_b = 1'b0;
   assign disp_data_out = 1'b0;
*/   // disp_data_in is an input

   // Buttons, Switches, and Individual LEDs
   //assign led = 8'hFF;
   // button0, button1, button2, button3, button_enter, button_right,
   // button_left, button_down, button_up, and switches are inputs

   // User I/Os
   assign user1 = 32'hZ;
   assign user2 = 32'hZ;
   assign user3 = 32'hZ;
   assign user4 = 32'hZ;

   // Daughtercard Connectors
   assign daughtercard = 44'hZ;

   // SystemACE Microprocessor Port
   assign systemace_data = 16'hZ;
   assign systemace_address = 7'h0;
   assign systemace_ce_b = 1'b1;
   assign systemace_we_b = 1'b1;
   assign systemace_oe_b = 1'b1;
   // systemace_irq and systemace_mpbrdy are inputs

   // Logic Analyzer
   assign analyzer1_data = 16'h0;
   assign analyzer1_clock = 1'b1;
   assign analyzer2_data = 16'h0;
   assign analyzer2_clock = 1'b1;
   assign analyzer3_data = 16'h0;
   assign analyzer3_clock = 1'b1;
   assign analyzer4_data = 16'h0;
   assign analyzer4_clock = 1'b1;


	////////////////////////////////////////////////////////////////
	// DIGIT DISPLAY MODULES
	////////////////////////////////////////////////////////////////
	wire [639:0] dots;
	wire [39:0] digit_dots;
	wire a,b,c,d,e,f,g;

	//Converts 4-bit input to 7-segment
	segment_decoder dec(switch[3:0], a,b,c,d,e,f,g);

	//Converts 7-segment display into LED dot matrix
	//	(instead of driving a 7-segment through I/O pins,
	//	 each segment is displayed using the Labkit's LED display)
	dot_converter cnv(a,b,c,d,e,f,g, digit_dots);

	//Driver for LED Display
	display disp(1'b0, clock_27mhz, disp_blank, disp_clock,
					disp_rs, disp_ce_b, disp_reset_b, disp_data_out, dots);



	assign dots	= {600'd0, digit_dots};
	assign led = ~{4'h0, switch[3:0]};

endmodule



///////////////////////////////////////////////////////////////////////////////
//
// 7-SEGMENT - DOT CONVERTER
//		6.111 (Spring 2006)
//		Created: January 5, 2006
//		Author:  Kyeong-Jae Lee
//
//		Note: Instead of driving a 7-segment through the I/O pins,
//				each segment is modeled and displayed using the Labkit's LED dot-matrix
///////////////////////////////////////////////////////////////////////////////
module dot_converter(a,b,c,d,e,f,g, dot_driver);
	input a,b,c,d,e,f,g;					// 7-segment drivers
	output [39:0] dot_driver;			//drives dot_matrix display

	//mask bits for each segment
	wire [39:0] mask_null = 40'h00_0000_0000;
	wire [39:0] mask_a 	 = 40'b00000001_00000001_00000001_00000001_00000001;
	wire [39:0] mask_b  	 = 40'b00000000_00000000_00000000_00000000_00001111;
	wire [39:0] mask_c 	 = 40'b00000000_00000000_00000000_00000000_01111000;
	wire [39:0] mask_d 	 = 40'b01000000_01000000_01000000_01000000_01000000;
	wire [39:0] mask_e 	 = 40'b01111000_00000000_00000000_00000000_00000000;
	wire [39:0] mask_f 	 = 40'b00001111_00000000_00000000_00000000_00000000;
	wire [39:0] mask_g 	 = 40'b00001000_00001000_00001000_00001000_00001000;

	wire [39:0]	dot_a = a ? mask_a : mask_null;
	wire [39:0]	dot_b = b ? mask_b : mask_null;
	wire [39:0]	dot_c = c ? mask_c : mask_null;
	wire [39:0]	dot_d = d ? mask_d : mask_null;
	wire [39:0]	dot_e = e ? mask_e : mask_null;
	wire [39:0]	dot_f = f ? mask_f : mask_null;
	wire [39:0]	dot_g = g ? mask_g : mask_null;

	//Combinatorially assign individual segments
	assign dot_driver = dot_a | dot_b | dot_c | dot_d | dot_e | dot_f | dot_g;
endmodule





///////////////////////////////////////////////////////////////////////////////
//
// 6.111 FPGA Labkit -- Alphanumeric Display Interface
//
//
// Created: November 5, 2003
// Author: Nathan Ickes
//
///////////////////////////////////////////////////////////////////////////////
//
// Change history
//
// 2005-05-09: Made <dots> input registered, and converted the 640-input MUX
//             to a 640-bit shift register.
//
///////////////////////////////////////////////////////////////////////////////

module display (reset, clock_27mhz,
		disp_blank, disp_clock, disp_rs, disp_ce_b,
		disp_reset_b, disp_data_out, dots);

   input  reset, clock_27mhz;
   output disp_blank, disp_clock, disp_data_out, disp_rs, disp_ce_b, 
	  disp_reset_b;
   input [639:0] dots;
   
   reg disp_data_out, disp_rs, disp_ce_b, disp_reset_b;

   ////////////////////////////////////////////////////////////////////////////
   //
   // Display Clock
   //
   // Generate a 500kHz clock for driving the displays.
   //
   ////////////////////////////////////////////////////////////////////////////
   
   reg [4:0] count;
   reg [7:0] reset_count;
   reg clock;
   wire dreset;

   always @(posedge clock_27mhz)
     begin
	if (reset)
	  begin
	     count = 0;
	     clock = 0;
	  end
	else if (count == 26)
	  begin
	     clock = ~clock;
	     count = 5'h00;
	  end
	else
	  count = count+1;
     end
   
   always @(posedge clock_27mhz)
     if (reset)
       reset_count <= 100;
     else
       reset_count <= (reset_count==0) ? 0 : reset_count-1;

   assign dreset = (reset_count != 0);

   assign disp_clock = ~clock;
   
   ////////////////////////////////////////////////////////////////////////////
   //
   // Display State Machine
   //
   ////////////////////////////////////////////////////////////////////////////
   
   reg [7:0] state;
   reg [9:0] dot_index;
   reg [31:0] control;
   reg [639:0] ldots;
   
   assign disp_blank = 1'b0; // low <= not blanked
   
   always @(posedge clock)
     if (dreset)
       begin
	  state <= 0;
	  dot_index <= 0;
	  control <= 32'h7F7F7F7F;
       end
     else
       casex (state)
	 8'h00:
	   begin
	      // Reset displays
	      disp_data_out <= 1'b0; 
	      disp_rs <= 1'b0; // dot register
	      disp_ce_b <= 1'b1;
	      disp_reset_b <= 1'b0;	     
	      dot_index <= 0;
	      state <= state+1;
	   end
	 
	 8'h01:
	   begin
	      // End reset
	      disp_reset_b <= 1'b1;
	      state <= state+1;
	   end
	 
	 8'h02:
	   begin
	      // Initialize dot register
	      disp_ce_b <= 1'b0;
	      disp_data_out <= 1'b0; // dot_index[0];
	      if (dot_index == 639)
		state <= state+1;
	      else
		dot_index <= dot_index+1;
	   end
	 
	 8'h03:
	   begin
	      // Latch dot data
	      disp_ce_b <= 1'b1;
	      dot_index <= 31;
	      state <= state+1;
	   end
	 
	 8'h04:
	   begin
	      // Setup the control register
	      disp_rs <= 1'b1; // Select the control register
	      disp_ce_b <= 1'b0;
	      disp_data_out <= control[31];
	      control <= {control[30:0], 1'b0};
	      if (dot_index == 0)
		state <= state+1;
	      else
		dot_index <= dot_index-1;
	   end
	  
	 8'h05:
	   begin
	      // Latch the control register data
	      disp_ce_b <= 1'b1;
	      dot_index <= 639;
	      ldots <= dots;
	      state <= state+1;
	   end
	 
	 8'h06:
	   begin
	      // Load the user's dot data into the dot register
	      disp_rs <= 1'b0; // Select the dot register
	      disp_ce_b <= 1'b0;
	      disp_data_out <= ldots[639];
	      ldots <= ldots<<1;
	      if (dot_index == 0)
		state <= 5;
	      else
		dot_index <= dot_index-1;
	   end
       endcase
   
endmodule