diff --git a/cpu_project/cpu_project.xpr b/cpu_project/cpu_project.xpr
index e605567..5c83a46 100644
--- a/cpu_project/cpu_project.xpr
+++ b/cpu_project/cpu_project.xpr
@@ -60,7 +60,7 @@
     <Option Name="IPStaticSourceDir" Val="$PIPUSERFILESDIR/ipstatic"/>
     <Option Name="EnableBDX" Val="FALSE"/>
     <Option Name="DSABoardId" Val="basys3"/>
-    <Option Name="WTXSimLaunchSim" Val="96"/>
+    <Option Name="WTXSimLaunchSim" Val="125"/>
     <Option Name="WTModelSimLaunchSim" Val="0"/>
     <Option Name="WTQuestaLaunchSim" Val="0"/>
     <Option Name="WTIesLaunchSim" Val="0"/>
@@ -91,6 +91,12 @@
   <FileSets Version="1" Minor="31">
     <FileSet Name="sources_1" Type="DesignSrcs" RelSrcDir="$PSRCDIR/sources_1" RelGenDir="$PGENDIR/sources_1">
       <Filter Type="Srcs"/>
+      <File Path="$PPRDIR/../src/alu.vhd">
+        <FileInfo>
+          <Attr Name="UsedIn" Val="synthesis"/>
+          <Attr Name="UsedIn" Val="simulation"/>
+        </FileInfo>
+      </File>
       <File Path="$PPRDIR/../src/instruction_memory.vhd">
         <FileInfo>
           <Attr Name="UsedIn" Val="synthesis"/>
@@ -103,6 +109,12 @@
           <Attr Name="UsedIn" Val="simulation"/>
         </FileInfo>
       </File>
+      <File Path="$PPRDIR/../src/mux/mux_ual.vhd">
+        <FileInfo>
+          <Attr Name="UsedIn" Val="synthesis"/>
+          <Attr Name="UsedIn" Val="simulation"/>
+        </FileInfo>
+      </File>
       <File Path="$PPRDIR/../src/pipeline_step.vhd">
         <FileInfo>
           <Attr Name="UsedIn" Val="synthesis"/>
@@ -121,13 +133,6 @@
           <Attr Name="UsedIn" Val="simulation"/>
         </FileInfo>
       </File>
-      <File Path="$PPRDIR/../src/alu.vhd">
-        <FileInfo>
-          <Attr Name="AutoDisabled" Val="1"/>
-          <Attr Name="UsedIn" Val="synthesis"/>
-          <Attr Name="UsedIn" Val="simulation"/>
-        </FileInfo>
-      </File>
       <File Path="$PPRDIR/../src/data_memory.vhd">
         <FileInfo>
           <Attr Name="AutoDisabled" Val="1"/>
diff --git a/src/cpu.vhd b/src/cpu.vhd
index e0bf248..5b806f3 100644
--- a/src/cpu.vhd
+++ b/src/cpu.vhd
@@ -9,8 +9,16 @@ entity cpu is
   );
 end cpu;
 
--- Multiplexers
 ARCHITECTURE cpu_arch OF cpu IS
+    -- Multiplexers
+    COMPONENT mux_ual IS
+        PORT (
+            mux_op: IN STD_LOGIC_VECTOR(3 downto 0);
+            mux_b_in: IN STD_LOGIC_VECTOR(7 downto 0);
+            mux_alu_s_in: IN STD_LOGIC_VECTOR(7 downto 0);
+            mux_sortie: OUT STD_LOGIC_VECTOR(7 downto 0)
+        );
+    END COMPONENT;
     COMPONENT mux_bdr IS
         PORT (
             mux_op: IN STD_LOGIC_VECTOR(3 downto 0);
@@ -19,6 +27,7 @@ ARCHITECTURE cpu_arch OF cpu IS
             mux_sortie: OUT STD_LOGIC_VECTOR(7 downto 0)
         );
     END COMPONENT;
+
     -- Logical components and memory
     COMPONENT instruction IS
 		PORT (
@@ -77,17 +86,18 @@ ARCHITECTURE cpu_arch OF cpu IS
     );
     END COMPONENT;
 
-    signal ex_A, mem_A, re_A  : STD_LOGIC_VECTOR(7 downto 0);
-    signal ex_B, mem_B, re_B : STD_LOGIC_VECTOR(7 downto 0);
-    signal ex_C, mem_C, re_C : STD_LOGIC_VECTOR(7 downto 0);
-    signal ex_OP, mem_OP, re_OP : STD_LOGIC_VECTOR(3 downto 0);
+    signal mem_A, re_A  : STD_LOGIC_VECTOR(7 downto 0);
+    signal mem_B, re_B : STD_LOGIC_VECTOR(7 downto 0);
+    signal mem_C, re_C : STD_LOGIC_VECTOR(7 downto 0);
+    signal mem_OP, re_OP : STD_LOGIC_VECTOR(3 downto 0);
+    
     -- Banc de registres
     signal di_A, di_B_in, di_B_out, di_C_in, di_C_out, qA : STD_LOGIC_VECTOR(7 downto 0);
     signal di_OP : STD_LOGIC_VECTOR(3 downto 0);
     signal write_enable : STD_LOGIC;
     -- UAL
-    signal ex_A_out, ex_A_in, ex_B_out, ex_B_in, ex_C_out, ex_C_in, S_ALU : STD_LOGIC_VECTOR(7 downto 0);
-    signal ex_OP_out, ex_OP_in : STD_LOGIC_VECTOR(3 downto 0);
+    signal ex_A, ex_B_out, ex_B_in, ex_C, S_ALU : STD_LOGIC_VECTOR(7 downto 0);
+    signal ex_OP : STD_LOGIC_VECTOR(3 downto 0);
     signal OP_ALU : STD_LOGIC_VECTOR(2 downto 0);
     -- Step 4
     signal W_enable: STD_LOGIC;
@@ -109,11 +119,18 @@ begin
     mux_bdr_inst :          mux_bdr PORT MAP(di_OP,di_B_out,qA,di_B_in);
 
     -- step2 pipeline
-    step2_diex  : pipeline_step PORT MAP(di_A, di_B_in, di_C_in, di_OP, clk, ex_A_in, ex_B_in, ex_C_in, ex_OP_in);
-    -- alu_inst                : alu PORT MAP(ex_B_out, ex_C_out, OP_ALU, S_ALU);
+    step2_diex :    pipeline_step PORT MAP(di_A, di_B_in, di_C_in, di_OP, clk, ex_A, ex_B_out, ex_C, ex_OP);
+    -- LC step 2
+    with ex_OP select
+        OP_ALU <=   "000" when X"1",
+                    "110" when X"2",
+                    "001" when X"3",
+                    "111" when others;
+    alu_inst :      alu PORT MAP(ex_B_out, ex_C, OP_ALU, S_ALU);
+    mux_ual_inst :  mux_ual PORT MAP(ex_OP,ex_B_out,S_ALU,ex_B_in);
     
     -- rest for now
-    step3_exmem : pipeline_step PORT MAP(ex_A_in, ex_B_in, ex_C_in, ex_OP_in, clk, mem_A, mem_B, mem_C, mem_OP);
+    step3_exmem : pipeline_step PORT MAP(ex_A, ex_B_in, ex_C, ex_OP, clk, mem_A, mem_B, mem_C, mem_OP);
     step4_memre : pipeline_step PORT MAP(mem_A, mem_B, mem_C, mem_OP, clk, re_A, re_B, re_C, re_OP);
     -- data_memory_inst        : data_memory PORT MAP();
 
@@ -123,6 +140,8 @@ begin
         W_enable <= '1' when X"6",
                     '1' when X"5",
                     '1' when X"1",
+                    '1' when X"2",
+                    '1' when X"3",
                     '0' when others;
 
     process(clk)
diff --git a/src/instruction_memory.vhd b/src/instruction_memory.vhd
index f579ea0..d211f97 100644
--- a/src/instruction_memory.vhd
+++ b/src/instruction_memory.vhd
@@ -25,10 +25,13 @@ entity instruction is
         end loop;
         init_result(0) := X"06010A00"; -- AFC 0x0a to R01
         init_result(1) := X"06020B00"; -- AFC 0x0b to R02
-        init_result(2) := X"06030C00"; -- AFC 0x0c to R03
+        init_result(2) := X"06030200"; -- AFC 0x0c to R03
         init_result(3) := X"06040D00"; -- AFC 0x0d to R04
         init_result(4) := X"06050E00"; -- AFC 0x0e to R05
         init_result(5) := X"05000100"; -- COPY R01 to R00
+        init_result(6) := X"01060102"; -- ADD R06=R01+R02
+        init_result(7) := X"02070103"; -- MUL R07=R01*R03
+        init_result(8) := X"03080201"; -- SOUS R08=R01-R02
         return init_result;
     end function init;
 end instruction;
diff --git a/src/mux/mux_bdr.vhd b/src/mux/mux_bdr.vhd
index 1fc6a32..46736d4 100644
--- a/src/mux/mux_bdr.vhd
+++ b/src/mux/mux_bdr.vhd
@@ -17,5 +17,7 @@ begin
     with mux_op select
         mux_sortie <=   mux_qa_in when X"5",
                         mux_qa_in when X"1",
+                        mux_qa_in when X"2",
+                        mux_qa_in when X"3",
                         mux_b_in when others;
 end Behavioral;
\ No newline at end of file
diff --git a/src/mux/mux_ual.vhd b/src/mux/mux_ual.vhd
new file mode 100644
index 0000000..d47816f
--- /dev/null
+++ b/src/mux/mux_ual.vhd
@@ -0,0 +1,22 @@
+library IEEE;
+use IEEE.STD_LOGIC_1164.ALL;
+use IEEE.STD_LOGIC_ARITH.ALL;
+use IEEE.STD_LOGIC_UNSIGNED.ALL;
+
+entity mux_ual is
+    PORT (
+        mux_op: IN STD_LOGIC_VECTOR(3 downto 0);
+        mux_b_in: IN STD_LOGIC_VECTOR(7 downto 0);
+        mux_alu_s_in: IN STD_LOGIC_VECTOR(7 downto 0);
+        mux_sortie: OUT STD_LOGIC_VECTOR(7 downto 0)
+    );
+end mux_ual;
+
+architecture Behavioral of mux_ual is
+begin
+    with mux_op select
+        mux_sortie <=   mux_alu_s_in when X"1",
+                        mux_alu_s_in when X"2",
+                        mux_alu_s_in when X"3",
+                        mux_b_in when others;
+end Behavioral;
\ No newline at end of file