Update sys. Re-organize the sources.

rtl/kempston_mouse.v

@@ -0,0 +1,66 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+//  PS2-to-Kempston Mouse v2
+//  (C) 2017,2018 Sorgelig
+//
+//  This program is free software; you can redistribute it and/or modify it
+//  under the terms of the GNU General Public License as published by the Free
+//  Software Foundation; either version 2 of the License, or (at your option)
+//  any later version.
+//
+//  This program 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 General Public License for
+//  more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with this program; if not, write to the Free Software Foundation, Inc.,
+//  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+module kempston_mouse
+(
+	input        clk_sys,
+	input        reset,
+
+	input [24:0] ps2_mouse,
+	
+	input  [2:0] addr,
+	output       sel,
+	output [7:0] dout
+);
+
+assign dout = data;
+assign sel  = port_sel;
+
+reg [11:0] dx;
+reg [11:0] dy;
+
+reg  [7:0] data;
+reg        port_sel;
+always @* begin
+	port_sel = 1;
+	casex(addr)
+		 3'b011: data = dx[7:0];
+		 3'b111: data = dy[7:0];
+		 3'bX10: data = ~{5'b00000,ps2_mouse[2], ps2_mouse[0], ps2_mouse[1]} ;
+		default: {port_sel,data} = 8'hFF;
+	endcase
+end
+
+always @(posedge clk_sys) begin
+	reg old_status;
+	old_status <= ps2_mouse[24];
+
+	if(reset) begin
+		dx <= 128; // dx != dy for better mouse detection
+		dy <= 0;
+	end
+	else if(old_status != ps2_mouse[24]) begin
+		dx <= dx + {{4{ps2_mouse[4]}},ps2_mouse[15:8]};
+		dy <= dy + {{4{ps2_mouse[5]}},ps2_mouse[23:16]};
+	end
+end
+
+endmodule