ps2lab1.v

module ps2lab1(
  // Clock Input (50 MHz)
  input  CLOCK_50,
  //  Push Buttons
  input  [3:0]  KEY,
  //  DPDT Switches 
  input  [17:0]  SW,
  //  7-SEG Displays
  output  [6:0]  HEX0, HEX1, HEX2, HEX3, HEX4, HEX5, HEX6, HEX7,
  //  LEDs
  output  [8:0]  LEDG,  //  LED Green[8:0]
  output  [17:0]  LEDR,  //  LED Red[17:0]
  //  PS2 data and clock lines		
  input	PS2_DAT,
  input	PS2_CLK,
  //  GPIO Connections
  inout  [35:0]  GPIO_0, GPIO_1
);

//  set all inout ports to tri-state
assign  GPIO_0    =  36'hzzzzzzzzz;
assign  GPIO_1    =  36'hzzzzzzzzz;

wire RST;
assign RST = KEY[0];


// Connect dip switches to red LEDs
assign LEDR[17:0] = SW[17:0];

// turn off green LEDs
assign LEDG = 0;

wire reset = 1'b0;
wire [7:0] scan_code;

reg [7:0] history[1:4];
wire read, scan_ready;

oneshot pulser(
   .pulse_out(read),
   .trigger_in(scan_ready),
   .clk(CLOCK_50)
);

keyboard kbd(
  .keyboard_clk(PS2_CLK),
  .keyboard_data(PS2_DAT),
  .clock50(CLOCK_50),
  .reset(reset),
  .read(read),
  .scan_ready(scan_ready),
  .scan_code(scan_code)
);

hex_7seg dsp0(history[1][3:0],HEX0);
hex_7seg dsp1(history[1][7:4],HEX1);

hex_7seg dsp2(history[2][3:0],HEX2);
hex_7seg dsp3(history[2][7:4],HEX3);

hex_7seg dsp4(history[3][3:0],HEX4);
hex_7seg dsp5(history[3][7:4],HEX5);

hex_7seg dsp6(history[4][3:0],HEX6);
hex_7seg dsp7(history[4][7:4],HEX7);



always @(posedge scan_ready)
begin
	history[4] <= history[3];
	history[3] <= history[2];
	history[2] <= history[1];
	history[1] <= scan_code;
end
	

// blank remaining digits
/*
wire [6:0] blank = 7'h7f;
assign HEX2 = blank;
assign HEX3 = blank;
assign HEX4 = blank;
assign HEX5 = blank;
assign HEX6 = blank;
assign HEX7 = blank;
*/

endmodule