// Basys Board and Spartan-3E Starter Board
// PS/2 Keyboard keyboard.v
// c 2008 Embedded Design using Programmable Gate Arrays  Dennis Silage

module keyboard(input wire PS2CLK, input wire PS2DAT, output reg dav,
					 output reg [7:0] kbddata, output reg parity);

reg [3:0] count = 0;
	
always @(negedge PS2CLK)		// read keyboard data
	begin
		count = count + 1;
		case (count)
			1: dav = PS2DAT;
			2: kbddata[0] = PS2DAT;
			3: kbddata[1] = PS2DAT;
			4: kbddata[2] = PS2DAT;
			5: kbddata[3] = PS2DAT;
			6: kbddata[4] = PS2DAT;
			7: kbddata[5] = PS2DAT;
			8: kbddata[6] = PS2DAT;
			9: kbddata[7] = PS2DAT;
			10: parity = PS2DAT;
			11: begin 
					count = 0;
					dav = PS2DAT;
				 end
		endcase
	end

endmodule