- added pin non-maskable interrupt (NMI).

Exception vector is reset vector at (X"BFC00000")


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git-svn-id: http://moon:8086/svn/vhdl/trunk@490 cc03376c-175c-47c8-b038-4cd826a8556b

projects/mips_sys/src/mips_sys.vhd

@@ -128,6 +128,7 @@ ARCHITECTURE behavior OF mips_sys IS
 	(
 		debug		: out unsigned(1 downto 0);
 		eb			: in  STD_LOGIC;
+		nmi			: in  STD_LOGIC;
 		RST_I		: in  STD_LOGIC;
 		CLK_I		: in  STD_LOGIC;
 		ACK_I		: in  STD_LOGIC;
@@ -303,6 +304,7 @@ ARCHITECTURE behavior OF mips_sys IS
 	);
 	END COMPONENT;
 
+	signal nmi			: std_logic;
 	signal rst			: std_logic;
 	signal clk			: std_logic;
 	signal eb			: std_logic;
@@ -436,7 +438,8 @@ BEGIN
 	gpi1(7 downto 0)	<= sys_dip;
 	sys_led				<= gpo0(8 downto 0);
 	sys_error			<= debug;
-	rst_in 				<= not sys_rst_n_in;
+	nmi					<= not sys_rst_n_in;
+	rst_in 				<= not sys_rst_n_in and sys_btn(0) and sys_btn(2);
 	rst					<= not locked;
 	sys_usb_rstn		<= not gpo1(0);
 	sys_flash_byten		<= '1';
@@ -588,6 +591,7 @@ inst_mips_top: mips_top
 	(
 		debug			=> debug,
 		eb				=> eb,
+		nmi				=> nmi,
 		RST_I			=> rst,
 		CLK_I			=> clk,
 		ACK_I			=> ACK_I_cpu,