Clarified description of new_interval.

applications/lofar2/libraries/sdp/src/vhdl/sdp_crosslets_subband_select.vhd

@@ -33,9 +33,12 @@
 --   The prev_crosslets_info identifies the crosslets that were calculated
 --   during the previous out_sosi.sync interval, so the XST for those crosslets
 --   are then pending to be offloaded.
--- * The new_interval is active before the first out_sosi.sync and inactive
---   before the next out_sosi.sync, so it can be used to know when a new
---   sequence of out_sosi.sync intervals starts.
+-- * The new_interval is active during the first in_sosi_arr.sync interval. The
+--   out_sosi.sync is active one sop period after the in_sosi_arr.sync. Hence
+--   the new_interval is active about one block before the first out_sosi.sync
+--   and inactive about one block before the next out_sosi.sync, so
+--   new_interval can be used to know when a new sequence of out_sosi.sync
+--   intervals starts.
 -- Remark:
 -- . See L5 SDPFW Design Document: Subband Correlator
 --   Link: https://support.astron.nl/confluence/pages/viewpage.action?spaceKey=L2M&title=L5+SDPFW+Design+Document%3A+Subband+Correlator