From ae9605f152547a52752a422d8cd693c42168c4b4 Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Tue, 13 Feb 2024 15:17:54 +0100
Subject: [PATCH] Use c_sdp_bdo_reorder_nof_blocks_max = 4 to save block RAM.
Ensure c_sdp_bdo_reorder_nof_blocks_max <= nof_bdo_destinations_max in
revision. Choose nof_bdo_destinations_max = 8.
---
.../lofar2/libraries/sdp/src/vhdl/sdp_bdo_pkg.vhd | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/applications/lofar2/libraries/sdp/src/vhdl/sdp_bdo_pkg.vhd b/applications/lofar2/libraries/sdp/src/vhdl/sdp_bdo_pkg.vhd
index e33f2166ab..33df8e23bc 100644
--- a/applications/lofar2/libraries/sdp/src/vhdl/sdp_bdo_pkg.vhd
+++ b/applications/lofar2/libraries/sdp/src/vhdl/sdp_bdo_pkg.vhd
@@ -59,11 +59,21 @@ package sdp_bdo_pkg is
-- nof_destinations > 1 and how many block RAM resources are available for
-- the reordering. Therefore c_sdp_bdo_reorder_nof_blocks_max = 16 is a
-- suitable compromise value.
- constant c_sdp_bdo_reorder_nof_blocks_max : natural := 16;
+ -- Conclusion:
+ -- . Choose c_sdp_bdo_reorder_nof_blocks_max = 4 to save block RAM resources,
+ -- and because it is acceptable to have smaller packets in case of more
+ -- than 4 destinations. Note that the reorder buffer is dual page.
+ -- . Choose nof_bdo_destinations_max = 8 in design revision, because it is
+ -- enough for CEP and to save logic resources and to ease timing closure.
+ -- Remark:
+ -- . The c_sdp_bdo_reorder_nof_blocks_max must be <=
+ -- nof_bdo_destinations_max, because otherwise this probably caused
+ -- Quartus synthesis to yield an segmentation error.
+ constant c_sdp_bdo_reorder_nof_blocks_max : natural := 4;
constant c_sdp_bdo_reorder_nof_blocks_w : natural := ceil_log2(c_sdp_bdo_reorder_nof_blocks_max + 1);
constant c_sdp_bdo_reorder_nof_ch_max : natural := c_sdp_bdo_reorder_nof_blocks_max *
c_sdp_nof_beamlets_per_block *
- c_sdp_nof_words_per_beamlet; -- = 7808
+ c_sdp_nof_words_per_beamlet; -- = 4 * 488 * 1 = 1952 32b
-- 32 * 3 + 4 = 100 fields
constant c_sdp_bdo_destinations_info_nof_hdr_fields : natural := c_sdp_bdo_mm_nof_destinations_max * 3 + 4;
--
GitLab