diff --git a/libraries/base/common/tb/vhdl/tb_common_variable_delay.vhd b/libraries/base/common/tb/vhdl/tb_common_variable_delay.vhd
index 41db5ceadba52269c6e34b57c35d7a8582ed819e..bc67fc6cb4d985770566be285331d223a0c9c52b 100644
--- a/libraries/base/common/tb/vhdl/tb_common_variable_delay.vhd
+++ b/libraries/base/common/tb/vhdl/tb_common_variable_delay.vhd
@@ -1,23 +1,30 @@
--------------------------------------------------------------------------------
---
--- Copyright (C) 2011
+-- --------------------------------------------------------------------------
+-- Copyright 2020
 -- ASTRON (Netherlands Institute for Radio Astronomy) <http://www.astron.nl/>
 -- P.O.Box 2, 7990 AA Dwingeloo, The Netherlands
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
---
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-- http://www.apache.org/licenses/LICENSE-2.0
 --
--------------------------------------------------------------------------------
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+-- --------------------------------------------------------------------------
+
+-- --------------------------------------------------------------------------
+-- Author:
+-- . Pieter Donker
+-- Purpose:
+-- . test bench for common_variable_delay.vhd
+-- Description:
+-- . see common_variable_delay.vhd
+-- --------------------------------------------------------------------------
+
 
 LIBRARY IEEE;
 USE IEEE.std_logic_1164.ALL;
@@ -79,7 +86,7 @@ BEGIN
     enable <= '1';
     -- enable trigger output and count clk's between trigger lo-hi and trigger_dly lo-hi
     -- check if counted clk's = c_trigger_latency + delay 
-    FOR i IN 0 TO c_delay_arr'LENGTH-1 LOOP
+    FOR i IN c_delay_arr'RANGE LOOP
       delay <= c_delay_arr(i);
       clk_cnt <= 0;
       proc_common_wait_until_lo_hi(clk, trigger);