Improved comment for proc_dp_verify_sync() for fractional sync periods.

libraries/base/dp/tb/vhdl/tb_dp_bsn_source_v2.vhd

@@ -223,8 +223,11 @@ BEGIN
   proc_dp_verify_sop_and_eop(clk, bs_sosi.valid, bs_sosi.sop, bs_sosi.eop, hold_bs_sop);  -- Verify that sop and eop come in pairs
   proc_dp_verify_sync(clk, verify_sync, bs_sosi.sync, bs_sosi.sop, expected_sync_dly);  -- Verify sync at sop and at expected_sync
 
-  -- Verify sync at sop and at expected_sync, but now using the
-  -- proc_dp_verify_sync() variant that can verify fractional sync periods
+  -- Verify sync at sop and at expected_sync again:
+  -- . now using the proc_dp_verify_sync() variant for dp_bsn_source_v2 that
+  --   can verify fractional sync periods.
+  -- . the proc_dp_verify_sync() v2 variant was made later, so in fact
+  --   this tb_dp_bsn_source_v2 verifies this new v2 procedure.
   proc_dp_verify_sync(TO_UINT(bsn_init),
                       g_pps_interval,
                       g_block_size,