diff --git a/exec_tb.vhdl b/exec_tb.vhdl
index 22b3af7..43400fd 100644
--- a/exec_tb.vhdl
+++ b/exec_tb.vhdl
@@ -112,6 +112,9 @@ begin
 	
 	ck <= not ck after 2 ns;
 	process
+	
+	    signal vexe_res : std_logic_vector(31 downto 0);
+	
 	begin
 	    -- add
         ck <= '0';
@@ -155,6 +158,9 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"0000001E";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+        
         -- add lsl
         ck <= '0';
         wait for 2 ns;
@@ -171,7 +177,7 @@ begin
         dec_shift_asr <= '0';
         dec_shift_ror <= '0';
         dec_shift_rrx <= '0';
-        dec_shift_val <= "00011"; --shift de 3
+        dec_shift_val <= "00011";
 
         dec_alu_add <= '1';
         dec_alu_and <= '0';
@@ -197,6 +203,9 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"00000780";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+        
         -- and
         ck <= '0';
         wait for 2 ns;
@@ -239,6 +248,10 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"01000000";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+
+        
         -- and lsr
         ck <= '0';
         wait for 2 ns;
@@ -281,6 +294,10 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"0000000";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+
+        
         -- mov
         ck <= '0';
         wait for 2 ns;
@@ -325,6 +342,10 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"FFFFFFFF";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+
+        
         -- or asr
         ck <= '0';
         wait for 2 ns;
@@ -371,6 +392,10 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"08000000";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+
+        
         -- or
         ck <= '0';
         wait for 2 ns;
@@ -413,6 +438,10 @@ begin
         ck <= '1';
         wait;
         
+        vexe_res <= x"01000001";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
+
+        
         -- xor
         ck <= '0';
         wait for 2 ns;
@@ -455,7 +484,8 @@ begin
         ck <= '1';
         wait;
         
-        
+        vexe_res <= x"00000001";
+        assert (exe_res = vexe_res) report "[error] lsl. vexe_res = " & integer'image(to_integer(unsigned(vexe_res))) & " versus exe_res = " & integer'image(to_integer(unsigned(exe_res))) severity error;
         
 	end process;