diff --git a/applications/lofar2/libraries/sdp/tb/vhdl/tb_sdp_pkg.vhd b/applications/lofar2/libraries/sdp/tb/vhdl/tb_sdp_pkg.vhd
index 355c337f364c42b2314e5c459a79d17a64388b52..566e679387dca76616e870952578ee1f08a65d2d 100644
--- a/applications/lofar2/libraries/sdp/tb/vhdl/tb_sdp_pkg.vhd
+++ b/applications/lofar2/libraries/sdp/tb/vhdl/tb_sdp_pkg.vhd
@@ -108,18 +108,20 @@ package tb_sdp_pkg is
   -----------------------------------------------------------------------------
   -- Beamlet output packet
   -----------------------------------------------------------------------------
-  -- beamlet part index in longword [0 : 3] = X, Y, X, Y
-  subtype t_sdp_beamlet_longword_list is t_slv_8_arr(0 to c_sdp_cep_nof_beamlets_per_longword * c_sdp_N_pol_bf - 1);
+  -- beamlet part index [0 : 3] of X, Y, X, Y in network longword:
+  -- . re[0 : 3] at 0, 2, 4, 6 in longword
+  -- . im[0 : 3] at 1, 3, 5, 7 in longword
+  subtype t_sdp_beamlet_part_arr is t_slv_8_arr(0 to c_sdp_cep_nof_beamlets_per_longword * c_sdp_N_pol_bf - 1);
 
-  -- beamlet part index in packet [0 : 4 * 488 * 2 - 1] = [0 : 3903]
+  -- beamlet part index in packet with 4 blocks [0 : 4 * 488 * 2 - 1] = [0 : 3903]
   subtype t_sdp_beamlet_packet_list is t_slv_8_arr(0 to c_sdp_cep_nof_beamlets_per_packet * c_sdp_N_pol_bf - 1);
 
-  -- beamlet part index in block [0 : 488 * 2 - 1] =  [0 : 975]
+  -- beamlet part index in one block [0 : 488 * 2 - 1] =  [0 : 975]
   subtype t_sdp_beamlet_block_list is t_slv_8_arr(0 to c_sdp_cep_nof_beamlets_per_block * c_sdp_N_pol_bf - 1);
 
-  function func_sdp_transpose_packet(nof_blocks_per_packet : natural;
-                                     nof_beamlets_per_block : natural;
-                                     packet_list : t_sdp_beamlet_packet_list) return t_sdp_beamlet_packet_list;
+  function func_sdp_bdo_transpose_packet(nof_blocks_per_packet : natural;
+                                         nof_beamlets_per_block : natural;
+                                         packet_list : t_sdp_beamlet_packet_list) return t_sdp_beamlet_packet_list;
 
 end package tb_sdp_pkg;
 
@@ -496,13 +498,14 @@ package body tb_sdp_pkg is
   -- . blet  0:487, 0:487, 0:487, 0:487,  for nof_beamlets_per_block = 488
   -- . v_in  0,1,2, ...            1951
   -- return v_list = transposed packet_list:
-  --             0,   1, ..., 487
-  --           0:3, 0:3, ..., 0:3
+  --                      0,              1, ...,               487
+  --                    0:3,            0:3, ...,               0:3
   --         0,488,976,1464, 1,489,977,1465, ..., 487,975,1463,1951
+  --
   -- . v_out 0,4,8,...,1948, 1,5,9,...,1949, 2,6,10,...,1950, 3,7,11,...,1951
-  function func_sdp_transpose_packet(nof_blocks_per_packet : natural;
-                                     nof_beamlets_per_block : natural;
-                                     packet_list : t_sdp_beamlet_packet_list) return t_sdp_beamlet_packet_list is
+  function func_sdp_bdo_transpose_packet(nof_blocks_per_packet : natural;
+                                         nof_beamlets_per_block : natural;
+                                         packet_list : t_sdp_beamlet_packet_list) return t_sdp_beamlet_packet_list is
     variable v_list : t_sdp_beamlet_packet_list;
     variable v_in   : natural;
     variable v_out  : natural;
@@ -514,6 +517,7 @@ package body tb_sdp_pkg is
         v_list(v_out) := packet_list(v_in);
       end loop;
    end loop;
-  end func_sdp_transpose_packet;
+   return v_list;
+  end func_sdp_bdo_transpose_packet;
 
 end tb_sdp_pkg;