X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/6c1f3ad98ccd156be88c4011206605d127abee74..HEAD:/core/GBZ80Core.v

diff --git a/core/GBZ80Core.v b/core/GBZ80Core.v
index b5a502c..4a1e256 100644
--- a/core/GBZ80Core.v
+++ b/core/GBZ80Core.v
@@ -233,8 +233,10 @@ module GBZ80Core(
 			end
 			wr <= 0;
 			rd <= 0;
+`ifdef isim
 			address <= 16'bxxxxxxxxxxxxxxxx;	// Make it obvious if something of type has happened.
 			wdata <= 8'bxxxxxxxx;
+`endif
 			state <= `STATE_EXECUTE;
 		end
 		`STATE_EXECUTE: begin
@@ -247,7 +249,10 @@ module GBZ80Core(
 			`include "allinsns.v"
 			`undef EXECUTE
 			default:
+			begin
+				address <= {7'h78,opcode};	// Have the CPU tell you F0xx if something's gone wrong.
 				$stop;
+			end
 			endcase
 			state <= `STATE_WRITEBACK;
 		end