diff --git a/libraries/base/dp/src/vhdl/dp_sync_checker.vhd b/libraries/base/dp/src/vhdl/dp_sync_checker.vhd
index 32a7de5be9fa62d4e85170a7c5da968bcdf50cf4..259c50b03ad4084ff155a6de7df42c38890a91da 100644
--- a/libraries/base/dp/src/vhdl/dp_sync_checker.vhd
+++ b/libraries/base/dp/src/vhdl/dp_sync_checker.vhd
@@ -24,7 +24,24 @@
 --          corrects if sync is too early or too late. 
 
 --
--- Description: 
+-- Description: The dp_sync_checker distinguishes three situations:
+--
+--              1. SYNC is ok
+--              In case the sync interval is as expected the input data is simply
+--              passed through to the output.
+--
+--              2. SYNC is too early
+--              When the sync is too early the data is still passed to the output,
+--              unitl the specief number of packets (g_nof_blk_per_sync) have been 
+--              send. The SYNC signal that was too early is suppressed and will not
+--              be visible at the output. Once the g_nof_blk_per_sync packets have 
+--              been send to the output the dp_sync_checker will wait until a new 
+--              sync has arrived. 
+--
+--              3. SYNC is too late
+--              When an expected SYNC is not found at the input the dp_sync_checker
+--              will stop passing data to the output and wait for the next SYNC on 
+--              the input. 
 --
 -- Remarks: Parsing of backpressure is not yet implemented,  since it was not 
 --          required for the first purpose of this block (in reorder_transpose).