X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/62940da0dd1b60db11e9861d6dd55a43c5756114..a8f4468d0cd6910eba8031e21038d76857a2c107:/Interrupt.v?ds=sidebyside

diff --git a/Interrupt.v b/Interrupt.v
index 1450b2c..2686146 100644
--- a/Interrupt.v
+++ b/Interrupt.v
@@ -19,10 +19,13 @@ module Interrupt(
 	reg [7:0] imask = 16'hFFFF;
 	reg [7:0] ihold = 8'b0;
 	wire [7:0] imasked = ihold & imask;
+	
+	reg rdlatch = 0;
+	reg [15:0] addrlatch = 0;
 
-	assign data = rd ?
-	                 (addr == `ADDR_IF) ? ihold :
-	                 (addr == `ADDR_IE) ? imask :
+	assign data = rdlatch ?
+	                 (addrlatch == `ADDR_IF) ? ihold :
+	                 (addrlatch == `ADDR_IE) ? imask :
 	                 8'bzzzzzzzz :
 		      8'bzzzzzzzz;
 
@@ -34,7 +37,7 @@ module Interrupt(
 		       imasked[3] ? 8'h58 :
 		       imasked[4] ? 8'h60 : 8'h00;
 
-	always @(negedge clk)
+	always @(posedge clk)
 	begin
 		if (wr && (addr == `ADDR_IF || addr == `ADDR_IE)) begin
 			case(addr)
@@ -45,6 +48,8 @@ module Interrupt(
 		end
 		else
 			ihold <= ihold | iflag;
+		rdlatch <= rd;
+		addrlatch <= addr;
 	end
 
 endmodule