From: Christopher Zihao Lu <czl@gurgle.weh.andrew.cmu.edu>
Date: Fri, 9 May 2008 09:53:20 +0000 (-0400)
Subject: added butans
X-Git-Url: http://git.joshuawise.com/fpgaboy.git/commitdiff_plain/47a8eefe3693f2cfc96488d8b557f72612d685e0?hp=--cc

added butans
---

47a8eefe3693f2cfc96488d8b557f72612d685e0
diff --git a/Buttons.v b/Buttons.v
new file mode 100644
index 0000000..6caecd6
--- /dev/null
+++ b/Buttons.v
@@ -0,0 +1,32 @@
+`define ADDR_P1 16'hFF10
+
+/* note: buttons are 'pressed' when the input is high */
+
+module Buttons(
+	input core_clk,
+	input wr,
+	input rd,
+	input [15:0] addr,
+	inout [7:0] data,
+	input [7:0] buttons
+	output reg int
+	);
+
+	reg [7:0] p1;
+	reg [3:0] oldp1013;
+
+	assign data = (rd && (addr == `ADDR_P1)) ? p1 : 8'bzzzzzzzz;
+
+	wire p1013 = (p1[4] ? 4'b1111 : ~buttons[3:0]) | (p1[5] ? 4'b1111 : ~buttons[7:4]);
+
+	always @ (negedge core_clk) begin
+		if(wr) begin
+			case(addr)
+			`ADDR_P1: p1[5:4] <= data[5:4];
+			endcase
+		end
+		p1[3:0] <= p1013;
+		oldp1013 <= p1013;
+		int <= | (oldp1013 & (oldp1013 ^ p1013));
+	end
+endmodule