- status register is always writable

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git-svn-id: http://moon:8086/svn/vhdl/trunk@457 cc03376c-175c-47c8-b038-4cd826a8556b

lib/CPUs/MIPS/src/core/mips_cop.vhd

@@ -68,6 +68,7 @@ architecture Behavioral of cop is
 	signal code_reg_we		: STD_LOGIC;
 	signal ip_reg_we		: STD_LOGIC;
 	signal bd				: STD_LOGIC;
+	signal sw_int			: unsigned(1 downto 0);
 	signal ip				: unsigned(7 downto 0);
 	signal im				: unsigned(7 downto 0);
 	signal status_save		: STD_LOGIC;
@@ -330,13 +331,13 @@ cop_ip_reg_write:
 	begin
 		if rising_edge(clk) then
 			if rst = '1' then
-				ip(1 downto 0) <= (others => '0');
+				sw_int	<= (others => '0');
 			elsif ctrl_in.sdu.WB_nop = '0' then
 				if ip_reg_we = '1' then
-					ip(1 downto 0) <= din(9 downto 8) and im(1 downto 0);
+					sw_int	<= din(9 downto 8);
 				end if;	
 			end if;	
-			ip(7 downto 2)	<= int and im(7 downto 2);
+			ip	<= (int & sw_int) and im;
 		end if;
 	end process;
 
@@ -420,9 +421,9 @@ cop_we_gen:
 					case cop_pipe_EX.reg_ptr is
 
 					when "01100" =>
-						stat_reg_we	<= not status(1) or status(28);
+						stat_reg_we	<= '1'; -- not status(1) or status(28);
 					when "01101" =>			
-						ip_reg_we	<= not status(1) or status(28);
+						ip_reg_we	<= '1'; -- not status(1) or status(28);
 					when "11111" =>
 						test_reg_we	<= '1'; -- not status(1) or status(28);
 					when others => null;
@@ -464,7 +465,7 @@ cop_status_reg_write:
 					status(3 downto 2)	<= status(5 downto 4);
 				elsif ctrl_in.sdu.WB_nop = '0' then
 					if stat_reg_we = '1' then
-						status				<= din;
+						status			<= din;
 					end if;
 				end if;	
 			end if;