diff --git a/router/parent_arbiter.vhdl b/router/parent_arbiter.vhdl
index 2a7e3b8..0fb1ff5 100644
--- a/router/parent_arbiter.vhdl
+++ b/router/parent_arbiter.vhdl
@@ -42,7 +42,7 @@ begin
                 pack_dest.copy_x := packets(i)(39 downto 35);
                 pack_dest.copy_y := packets(i)(34 downto 30);
                 dirs(i) <= single_packet_parent_rout_dir_det(level, 
-                                                pack_dest, rout_pos);
+                        pack_dest, rout_pos);
             else
                 dirs(i) <= (others => '0');
             end if;
@@ -84,19 +84,37 @@ begin
                     avai_pos_nxt(avai_index) <= i;
                     avai_pos_sizes(3) := avai_pos_sizes(3) + 1;
                 end if;
-            else
+            elsif i < num_paths_down*4 + num_paths_up then
                 if avai_path = '1' then
                     avai_index := avai_pos_sizes(4) + num_paths_down*4;
                     avai_pos_nxt(avai_index) <= i;
                     avai_pos_sizes(4) := avai_pos_sizes(4) + 1;
                 end if;
+            elsif i < num_paths_down*4 + num_paths_up*2 then
+                if avai_path = '1' then
+                    avai_index := avai_pos_sizes(5)+num_paths_down*4+num_paths_up;
+                    avai_pos_nxt(avai_index) <= i;
+                    avai_pos_sizes(5) := avai_pos_sizes(5) + 1;
+                end if;
+            elsif i < num_paths_down*4 + num_paths_up*3 then
+                if avai_path = '1' then
+                    avai_index:=avai_pos_sizes(6)+num_paths_down*4+num_paths_up*2;
+                    avai_pos_nxt(avai_index) <= i;
+                    avai_pos_sizes(6) := avai_pos_sizes(6) + 1;
+                end if;
+            else
+                if avai_path = '1' then
+                    avai_index:=avai_pos_sizes(7)+num_paths_down*4+num_paths_up*3;
+                    avai_pos_nxt(avai_index) <= i;
+                    avai_pos_sizes(7) := avai_pos_sizes(7) + 1;
+                end if;
             end if;
         end loop;
         
         -- set rout_dirs to 0 when no more avai_pos (avai_pos_sizes(i) = 0)
         for i in 0 to TOT_NUM_PATHS-1  loop
             sum_dirs := 0;
-            for j in 0 to NUM_DIRS-1 loop
+            for j in 0 to NUM_DIRS_PARENT-1 loop
                 sum_dirs := sum_dirs + to_integer(unsigned'('0' & dirs(i)(j)));
             end loop;
             -- unicast
@@ -109,8 +127,14 @@ begin
                     j := 2;
                 elsif dirs(i)(3) = '1' then
                     j := 3;
-                else
+                elsif dirs(i)(4) = '1' then
                     j := 4;
+                elsif dirs(i)(5) = '1' then
+                    j := 5;
+                elsif dirs(i)(6) = '1' then
+                    j := 6;
+                else
+                    j := 7;
                 end if;
                 if avai_pos_sizes(j) <= 0 then
                     ps_dirs(i) <= (others => '0');
@@ -170,7 +194,7 @@ begin
             buff_wr_in(i).wr_req   <= '0';
             arb_complete(i)        <= '0';
         end loop;
-        for j in 0 to NUM_DIRS-1 loop
+        for j in 0 to NUM_DIRS_PARENT-1 loop
             path_index := 0;
             for i in 0 to TOT_NUM_PATHS-1 loop
                 if ps_dirs(i)(j)='1' then
diff --git a/router/router_types.vhdl b/router/router_types.vhdl
index c26a453..be6ad9d 100644
--- a/router/router_types.vhdl
+++ b/router/router_types.vhdl
@@ -25,7 +25,7 @@ package router_types is
                             integer range 0 to MAX_PATHS_SIZE;
     type t_EX_AVAI_POS is array(integer range <>) of 
                             integer range 0 to MAX_EX_PATHS_SIZE;
-    type t_EX_AVAI_POS_SIZES is array(NUM_DIRS-1 downto 0) of 
+    type t_EX_AVAI_POS_SIZES is array(NUM_DIRS_PARENT-1 downto 0) of 
                             integer range 0 to MAX_EX_PATHS_SIZE;
 
     type t_fifo_wr_in is record
diff --git a/router/routing_functions.vhdl b/router/routing_functions.vhdl
index a4f1b46..acaf707 100644
--- a/router/routing_functions.vhdl
+++ b/router/routing_functions.vhdl
@@ -41,8 +41,14 @@ package body routing_functions is
         pack_dest     :   in t_pos_addr; 
         rout_pos      :   in t_pos_addr
     ) return std_logic_vector is
-        variable chip_d_x, chip_d_y, chip_r_x, chip_r_y :   std_logic;
+        variable chip_d_x, chip_d_y : std_logic_vector(CHIP_ADDR_SIZE-1 downto 0); 
+        variable chip_r_x, chip_r_y : std_logic_vector(CHIP_ADDR_SIZE-1 downto 0);
     begin
+        chip_r_x := rout_pos.chip_x;
+        chip_r_y := rout_pos.chip_y;
+        chip_d_x := pack_dest.chip_x;
+        chip_d_y := pack_dest.chip_y;
+        
         if chip_d_y < chip_r_y then
             return "10000000"; -- north
         elsif chip_d_y > chip_r_y then
@@ -66,7 +72,7 @@ package body routing_functions is
         variable dest_x, dest_y, copy_x, copy_y :   std_logic;
         variable is_other_chip                  :   boolean;
         variable is_cousin_core                 :   boolean;
-        variable needs_multicast               :   boolean;
+        variable needs_multicast                :   boolean;
     begin
         dest_x := pack_dest.core_x(level-1);
         dest_y := pack_dest.core_y(level-1);
@@ -166,9 +172,18 @@ package body routing_functions is
         elsif dir = 3 then
             avai_pos_index := path_index+num_paths_down*3;
             return avai_pos(avai_pos_index);
-        else
+        elsif dir = 4 then
             avai_pos_index := path_index+num_paths_down*4;
             return avai_pos(avai_pos_index);
+        elsif dir = 5 then
+            avai_pos_index := path_index+num_paths_down*4+num_paths_up;
+            return avai_pos(avai_pos_index);
+        elsif dir = 6 then
+            avai_pos_index := path_index+num_paths_down*4+num_paths_up*2;
+            return avai_pos(avai_pos_index);
+        else
+            avai_pos_index := path_index+num_paths_down*4+num_paths_up*3;
+            return avai_pos(avai_pos_index);
         end if;
     end retrieve_ex_avai_path_index;
 end package body;
\ No newline at end of file
diff --git a/test/input/noc_tests/pe_to_chip_test/result.ref b/test/input/noc_tests/pe_to_chip_test/result.ref
new file mode 100644
index 0000000..72f3966
--- /dev/null
+++ b/test/input/noc_tests/pe_to_chip_test/result.ref
@@ -0,0 +1 @@
+1 64 0001000001000010001000010000000000000000000000000000000000000100
\ No newline at end of file
diff --git a/test/input/noc_tests/pe_to_chip_test/stimuli.txt b/test/input/noc_tests/pe_to_chip_test/stimuli.txt
new file mode 100644
index 0000000..f1527e2
--- /dev/null
+++ b/test/input/noc_tests/pe_to_chip_test/stimuli.txt
@@ -0,0 +1,2 @@
+# is external? | path | data
+0 0 0001000001000010001000010000000000000000000000000000000000000100 # south
diff --git a/test/input/noc_tests/simple_interchip_test/result.ref b/test/input/noc_tests/simple_interchip_test/result.ref
new file mode 100644
index 0000000..848816a
--- /dev/null
+++ b/test/input/noc_tests/simple_interchip_test/result.ref
@@ -0,0 +1 @@
+0 1023 0001000000000000000000000000000000000000000000000000000000000111
\ No newline at end of file
diff --git a/test/input/noc_tests/simple_interchip_test/stimuli.txt b/test/input/noc_tests/simple_interchip_test/stimuli.txt
new file mode 100644
index 0000000..cf44e80
--- /dev/null
+++ b/test/input/noc_tests/simple_interchip_test/stimuli.txt
@@ -0,0 +1,2 @@
+# is external? | path | data
+1 7 0001000000000000000000000000000000000000000000000000000000000111
diff --git a/test/noc_tb.vhdl b/test/noc_tb.vhdl
index 06fd68f..e3b1b3c 100644
--- a/test/noc_tb.vhdl
+++ b/test/noc_tb.vhdl
@@ -2,6 +2,9 @@ library ieee;
 use ieee.std_logic_1164.all;
 use ieee.numeric_std.all;
 
+use ieee.std_logic_textio.all;
+use std.textio.all;
+
 use work.router_types.all;
 
 entity noc_tb is
@@ -33,6 +36,70 @@ architecture bench of noc_tb is
   signal pe_data_out : t_DATA(4**level-1 downto 0);
   signal pe_rcv_acks : std_logic_vector(4**level-1 downto 0);
   signal pe_send_reqs : std_logic_vector(4**level-1 downto 0);
+  
+  signal c_send_reqs_prev : std_logic_vector(4*num_paths_ext-1 downto 0);
+  signal pe_send_reqs_prev : std_logic_vector(4**level-1 downto 0);
+
+  file conf_file            : text open read_mode is "config.txt";
+  file stimuli_file         : text open read_mode is "stimuli.txt";
+  file reference_file       : text open read_mode is "result.ref";
+  file log_file             : text open write_mode is "simulation.log";
+
+  procedure log_test_result (
+      index                         : integer;
+      sollwert, istwert             : WORD;
+      is_external, soll_is_external : boolean;
+      sollpath, istpath             : integer
+    ) is
+    variable rowOut       : LINE;
+  begin
+    write(rowOut, index);
+    if is_external then
+      write(rowOut, string'(" = loop (path/fifo - external)"));
+    else
+      write(rowOut, string'(" = loop (path/fifo - PE)"));
+    end if;  
+    WRITELINE(log_file, rowOut);
+
+    write(rowOut, string'("-->"));
+    write(rowOut, sollwert);
+    write(rowOut, string'(" = sollwert"));
+    WRITELINE(log_file, rowOut);
+    write(rowOut, string'("-->"));
+    write(rowOut, istwert);
+    write(rowOut, string'(" = istwert"));
+    WRITELINE(log_file, rowOut);
+
+    write(rowOut, string'("-->"));
+    write(rowOut, soll_is_external);
+    write(rowOut, string'(" = soll is_external"));
+    WRITELINE(log_file, rowOut);
+    write(rowOut, string'("-->"));
+    write(rowOut, is_external);
+    write(rowOut, string'(" = ist is_external"));
+    WRITELINE(log_file, rowOut);
+
+    write(rowOut, string'("-->"));
+    write(rowOut, sollpath);
+    write(rowOut, string'(" = sollpath"));
+    WRITELINE(log_file, rowOut);
+    write(rowOut, string'("-->"));
+    write(rowOut, istpath);
+    write(rowOut, string'(" = istpath"));
+    WRITELINE(log_file, rowOut);
+
+    if istwert = sollwert and is_external = soll_is_external then
+      write(rowOut, string'("-------------------------->pass"));
+      WRITELINE(log_file, rowOut);
+      write(rowOut, string'("******************************"));
+      WRITELINE(log_file, rowOut);
+    else
+      write(rowOut, string'("-------------------------->fail"));
+      WRITELINE(log_file, rowOut);
+      write(rowOut, string'("******************************"));
+      WRITELINE(log_file, rowOut);
+    end if;
+  end procedure;
 begin
 
   noc_inst : entity work.noc
@@ -70,7 +137,12 @@ begin
       wait for clk_period/2;
   end process;
 
-  test: process
+  gen_stimuli: process
+    variable input_line, rowOut : line;
+    variable valid_data         : boolean;
+    variable is_external        : std_logic_vector(0 downto 0);
+    variable path               : integer;
+    variable data               : std_logic_vector(63 downto 0);
   begin
     arstN <= '0';
     data_chip_in <= (others => (others => '0'));
@@ -82,8 +154,125 @@ begin
     wait until rising_edge(clk);
     arstN <= '1';
     wait until rising_edge(clk);
-    data_chip_in(0) <= "0001000000000000000000000000000000000000000000000000000000000111";
-    c_rcv_reqs(0) <= '1';
+    while not(endfile(stimuli_file)) loop
+      readline(stimuli_file, input_line);
+      if input_line.all'length = 0 then
+        wait until rising_edge(clk);
+        next;
+      elsif input_line.all(1) = '#' then
+        next;
+      end if;
+
+      read(input_line, is_external, valid_data);
+      assert valid_data 
+      report "Invalid data in file (is_external)" severity error;
+
+      read(input_line, path, valid_data);
+      assert valid_data 
+      report "Invalid data in file (path)" severity error;
+      
+      read(input_line, data, valid_data);
+      assert valid_data 
+      report "Invalid data in file (data)" severity error;
+
+      if is_external = "1" then
+        assert path < num_paths_ext-1
+        report "Invalid path index value in file (external)" severity error;
+        data_chip_in(path) <= data;
+        c_rcv_reqs(path)   <= not c_rcv_reqs(path);
+      else
+        assert path < 4**level-1
+        report "Invalid path index value in file (ds)" severity error;
+        pe_data_in(path)   <= data;
+        pe_rcv_reqs(path)  <= not pe_rcv_reqs(path);
+      end if;
+      exit when endfile(stimuli_file);
+    end loop;
     wait;
   end process;
+
+  validate_results: process(c_send_reqs, pe_send_reqs, 
+                c_send_reqs_prev, pe_send_reqs_prev, 
+                data_chip_out, pe_data_out)
+    variable input_line           : line;
+    variable valid_data           : boolean;
+    variable istwert, sollwert    : WORD;
+    variable is_external          : std_logic_vector(0 downto 0);
+    variable ist_is_external      : boolean;
+    variable istpath, sollpath    : integer;
+  begin
+    if c_send_reqs'event or c_send_reqs_prev'event then
+      for i in 0 to num_paths_ext*4-1 loop
+        if (c_send_reqs(i) = '0' and c_send_reqs_prev(i) = '1') or
+                (c_send_reqs(i) = '1' and c_send_reqs_prev(i) = '0') then
+          istwert  := data_chip_out(i);
+          istpath := i;
+          readline(reference_file, input_line);
+
+          read(input_line, is_external, valid_data);
+          assert valid_data report "Invalid data in file (is external)" 
+            severity error;
+
+          ist_is_external := is_external(0) = '1';
+          assert ist_is_external report "Invalid result (is external)" 
+            severity warning;
+
+          read(input_line, sollpath, valid_data);
+          assert valid_data report "Invalid data in file (path)" 
+            severity error;
+          assert istpath = sollpath report "Invalid result (path)"
+            severity warning;
+
+          read(input_line, sollwert, valid_data);
+          assert valid_data report "Invalid data in file (data)" 
+            severity error;
+          assert istwert = sollwert report "Invalid result (data)" 
+            severity warning;
+            
+          log_test_result(i, istwert, sollwert, TRUE, ist_is_external, 
+                            sollpath, istpath);
+        end if;
+      end loop;
+    elsif pe_send_reqs'event or pe_send_reqs_prev'event then
+      for i in 0 to 4**level-1 loop
+        if (pe_send_reqs(i) = '0' and pe_send_reqs_prev(i) = '1') or
+                (pe_send_reqs(i) = '1' and pe_send_reqs_prev(i) = '0') then
+          istwert := pe_data_out(i);
+          istpath := i;
+          readline(reference_file, input_line);
+          
+          read(input_line, is_external, valid_data);
+          assert valid_data report "Invalid data in file (is external)" 
+            severity error;
+
+          ist_is_external := is_external(0) = '1';
+          assert not ist_is_external report "Invalid result (is external)" 
+            severity warning;
+
+          read(input_line, sollpath, valid_data);
+          assert valid_data report "Invalid data in file (path)" 
+            severity error;
+          assert istpath = sollpath report "Invalid result (path)"
+            severity warning;
+
+          read(input_line, sollwert, valid_data);
+          assert valid_data report "Invalid data in file (data)" 
+            severity error;
+          assert istwert = sollwert report "Invalid result (data)" 
+            severity warning;
+
+          log_test_result(i, istwert, sollwert, FALSE, ist_is_external, 
+                            sollpath, istpath);
+        end if;
+      end loop;
+    end if;
+  end process;
+
+  update_signals: process(clk)
+  begin
+    if rising_edge(clk) then
+      c_send_reqs_prev <= c_send_reqs;
+      pe_send_reqs_prev <= pe_send_reqs;
+    end if;
+  end process;
 end;
\ No newline at end of file