diff --git a/lib/CPUs/MIPS/sim/tb_mips_top.fdo b/lib/CPUs/MIPS/sim/tb_mips_top.fdo
index c843b12..2a6562f 100644
--- a/lib/CPUs/MIPS/sim/tb_mips_top.fdo
+++ b/lib/CPUs/MIPS/sim/tb_mips_top.fdo
@@ -57,4 +57,4 @@ do {tb_mips_top.wdo}
 view wave
 view structure
 view signals
-run 1200us
+run 1600us
diff --git a/lib/CPUs/MIPS/src/tb_mips_top.vhd b/lib/CPUs/MIPS/src/tb_mips_top.vhd
index 52a2e69..3c8b52a 100644
--- a/lib/CPUs/MIPS/src/tb_mips_top.vhd
+++ b/lib/CPUs/MIPS/src/tb_mips_top.vhd
@@ -97,11 +97,11 @@ ARCHITECTURE behavior OF tb_mips_top IS
 
 	signal gpo0			: unsigned(31 downto 0);
 	signal gpo1			: unsigned(31 downto 0);
-	signal gpi0			: unsigned(31 downto 0);
-	signal gpi1			: unsigned(31 downto 0);
-
+	signal gpi0			: unsigned(31 downto 0) := (others => '0');
+	signal gpi1			: unsigned(31 downto 0) := (others => '0');
+	
 	signal int_uart_rx	: std_logic;
-	signal rx			: std_logic;
+	signal rx			: std_logic := '1';
 	signal tx			: std_logic;
 
 	type mem_area_t is (mem_dead, mem_flash, mem_sram, mem_rom, mem_gpio, mem_uart);