diff --git a/libraries/dsp/correlator/hdllib.cfg b/libraries/dsp/correlator/hdllib.cfg
index 6e4e375559dba7dce9dc2b3fee3e74fa89967079..8072cbdb51bec8e4d7273772ef90d2892465f205 100644
--- a/libraries/dsp/correlator/hdllib.cfg
+++ b/libraries/dsp/correlator/hdllib.cfg
@@ -13,6 +13,7 @@ synth_files =
$SVN/RadioHDL/trunk/libraries/dsp/correlator/src/vhdl/corr_multiplier.vhd
$SVN/RadioHDL/trunk/libraries/dsp/correlator/src/vhdl/corr_adder.vhd
$SVN/RadioHDL/trunk/libraries/dsp/correlator/src/vhdl/corr_accumulator.vhd
+ $SVN/RadioHDL/trunk/libraries/dsp/correlator/src/vhdl/corr_visibility_buffer.vhd
$SVN/RadioHDL/trunk/libraries/dsp/correlator/src/vhdl/correlator.vhd
test_bench_files =
diff --git a/libraries/dsp/correlator/src/vhdl/corr_visibility_buffer.vhd b/libraries/dsp/correlator/src/vhdl/corr_visibility_buffer.vhd
new file mode 100644
index 0000000000000000000000000000000000000000..4d0cc9ec599de47eb0ab4feaddee14db9ac0fb86
--- /dev/null
+++ b/libraries/dsp/correlator/src/vhdl/corr_visibility_buffer.vhd
@@ -0,0 +1,127 @@
+--------------------------------------------------------------------------------
+--
+-- Copyright (C) 2014
+-- 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.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+--
+--------------------------------------------------------------------------------
+
+LIBRARY IEEE, common_lib, dp_lib;
+USE IEEE.std_logic_1164.ALL;
+USE IEEE.numeric_std.ALL;
+USE common_lib.common_pkg.ALL;
+USE dp_lib.dp_stream_pkg.ALL;
+
+-- Purpose:
+-- . Buffer the visibilities during folding
+-- Description:
+-- . Consists of an array of FIFOs that are read out periodically
+
+ENTITY corr_visibility_buffer IS
+ GENERIC (
+ g_nof_inputs : NATURAL; -- Number of input streams
+ g_nof_channels : NATURAL; -- Number of channels per visibility
+ g_data_w : NATURAL -- Complex input data width
+ );
+ PORT (
+ rst : IN STD_LOGIC;
+ clk : IN STD_LOGIC;
+
+ snk_in_arr : IN t_dp_sosi_arr(g_nof_inputs-1 DOWNTO 0);
+ src_out_arr : OUT t_dp_sosi_arr(g_nof_inputs-1 DOWNTO 0)
+ );
+END corr_visibility_buffer;
+
+ARCHITECTURE str OF corr_visibility_buffer IS
+
+ SIGNAL dp_fifo_sc_src_out_arr : t_dp_sosi_arr(g_nof_inputs-1 DOWNTO 0);
+ SIGNAL dp_fifo_sc_src_in_arr : t_dp_siso_arr(g_nof_inputs-1 DOWNTO 0);
+
+BEGIN
+
+ ------------------------------------------------------------------------------
+ -- Buffer the visibilities before the folding stage.
+ -- . All accumulators output blocks of visibilities at the same time. We need
+ -- to buffer the visibilities to source them to the folder at the right
+ -- pace.
+ ------------------------------------------------------------------------------
+ gen_dp_fifo_sc : FOR i IN 0 TO g_nof_inputs-1 GENERATE
+ u_dp_fifo_sc : ENTITY dp_lib.dp_fifo_sc
+ GENERIC MAP (
+ g_data_w => 2*g_data_w,
+ g_use_ctrl => FALSE,
+ g_use_complex => TRUE,
+ g_fifo_size => g_nof_channels,
+ g_fifo_af_margin => 0
+ )
+ PORT MAP (
+ rst => rst,
+ clk => clk,
+
+ wr_ful => OPEN,
+ usedw => OPEN,
+ rd_emp => OPEN,
+
+ snk_out => OPEN,
+ snk_in => snk_in_arr(i),
+ src_in => dp_fifo_sc_src_in_arr(i),
+ src_out => dp_fifo_sc_src_out_arr(i)
+ );
+ END GENERATE;
+
+ ------------------------------------------------------------------------------
+ -- Read out the FIFOs such that dp_fifo_sc_src_out_arr only carries one valid
+ -- word per cycle. This allows folding (multiplexing) into one stream without
+ -- losing data (example for 16 streams):
+ --
+ -- |<--g_nof_invalid_per_valid-->|
+ -- 0) [0] [1] ..
+ -- 1) | [0] . [1]
+ -- 2) | [0] . [1]
+ -- 3) | [0] . [1]
+ -- 4) | [0] . [1]
+ -- 5) | [0] . [1]
+ -- 6) | [0] . [1]
+ -- 7) | [0] . [1]
+ -- 8) | [0] . [1]
+ -- 9) | [0] . [1]
+ -- 10) | [0] . [1]
+ -- 11) | [0] . [1]
+ -- 12) | [0] . [1]
+ -- 13) | [0] . [1]
+ -- 14) | [0] . [1]
+ -- 15) |<---g_init_valid_delay(15)-->[0] [1]
+ ------------------------------------------------------------------------------
+ gen_dp_src_out_timer : FOR i IN 0 TO g_nof_inputs-1 GENERATE
+ u_dp_src_out_timer : ENTITY dp_lib.dp_src_out_timer
+ GENERIC MAP (
+ g_init_valid_delay => i, --relative to dp_fifo_sc_src_out_arr(i).valid
+ g_nof_invalid_per_valid => g_nof_inputs
+ )
+ PORT MAP (
+ rst => rst,
+ clk => clk,
+
+ init_valid_delay_ref => snk_in_arr(i).valid,
+
+ snk_in => dp_fifo_sc_src_out_arr(i),
+ snk_out => dp_fifo_sc_src_in_arr(i)
+ );
+ END GENERATE;
+
+ src_out_arr <= dp_fifo_sc_src_out_arr;
+
+END str;
diff --git a/libraries/dsp/correlator/src/vhdl/correlator.vhd b/libraries/dsp/correlator/src/vhdl/correlator.vhd
index 715e115a74f42afd3ded8c0401c2f43709e2a5f3..ab8b6d69e31075e8760a98c726ac751d351f3d97 100644
--- a/libraries/dsp/correlator/src/vhdl/correlator.vhd
+++ b/libraries/dsp/correlator/src/vhdl/correlator.vhd
@@ -51,7 +51,7 @@ END correlator;
ARCHITECTURE str OF correlator IS
- CONSTANT c_nof_visibilities : NATURAL := (g_nof_inputs*(g_nof_inputs+1))/2;
+ CONSTANT c_nof_visibilities : NATURAL := (g_nof_inputs*(g_nof_inputs+1))/2;
-----------------------------------------------------------------------------
-- The array of multiplier input streams can be folded, e.g.:
@@ -62,24 +62,23 @@ ARCHITECTURE str OF correlator IS
-- . c_nof_visibilities=10, g_nof_pre_mult_folds=4 -> c_nof_mults= 1
-- . c_nof_visibilities=10, g_nof_pre_mult_folds<0 -> c_nof_mults= 1
-----------------------------------------------------------------------------
- CONSTANT c_nof_mults : NATURAL := sel_a_b(g_nof_pre_mult_folds>=0, ceil_div(c_nof_visibilities, ceil_pow2(g_nof_pre_mult_folds)), 1);
+ CONSTANT c_nof_mults : NATURAL := sel_a_b(g_nof_pre_mult_folds>=0, ceil_div(c_nof_visibilities, ceil_pow2(g_nof_pre_mult_folds)), 1);
-- We can multiplex the accumulator outputs onto one stream as long as the integration period is
-- equal to or larger than the number of accumulator outputs.
- CONSTANT c_integration_period : NATURAL := largest(g_integration_period, c_nof_mults);
+ CONSTANT c_integration_period : NATURAL := largest(g_integration_period, c_nof_mults);
- CONSTANT c_acc_data_w : NATURAL := ceil_log2(c_integration_period*(pow2(g_data_w)-1));
+ CONSTANT c_acc_data_w : NATURAL := ceil_log2(c_integration_period*(pow2(g_data_w)-1));
- SIGNAL corr_permutator_src_out_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs
- SIGNAL corr_folder_snk_in_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs, not folded yet
- SIGNAL corr_folder_src_out_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs, not folded yet
- SIGNAL corr_multiplier_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL corr_accumulator_snk_in_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL corr_accumulator_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL dp_fifo_sc_snk_in_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL dp_fifo_sc_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL dp_fifo_sc_src_in_arr : t_dp_siso_arr(c_nof_mults-1 DOWNTO 0);
- SIGNAL corr_folder_src_out_arr : t_dp_sosi_arr(1-1 DOWNTO 0);
+ SIGNAL corr_permutator_src_out_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs
+ SIGNAL corr_folder_snk_in_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs, not folded yet
+ SIGNAL corr_folder_src_out_2arr_2 : t_dp_sosi_2arr_2(g_nof_inputs*(g_nof_inputs+1)/2-1 DOWNTO 0); -- Array of pairs, not folded yet
+ SIGNAL corr_multiplier_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
+ SIGNAL corr_accumulator_snk_in_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
+ SIGNAL corr_accumulator_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
+ SIGNAL corr_visibility_buffer_snk_in_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
+ SIGNAL corr_visibility_buffer_src_out_arr : t_dp_sosi_arr(c_nof_mults-1 DOWNTO 0);
+ SIGNAL corr_folder_src_out_arr : t_dp_sosi_arr(1-1 DOWNTO 0);
BEGIN
@@ -188,79 +187,28 @@ BEGIN
clk => clk,
snk_in => corr_accumulator_src_out_arr(i),
- src_out => dp_fifo_sc_snk_in_arr(i)
+ src_out => corr_visibility_buffer_snk_in_arr(i)
);
END GENERATE;
------------------------------------------------------------------------------
-- Buffer the visibilities before the folding stage.
-- . All accumulators output blocks of visibilities at the same time. We need
- -- to buffer the visibilities so we can take our time to multiplex them
- -- onto one stream.
+ -- to buffer the visibilities to source them to the folder at the right
+ -- pace.
------------------------------------------------------------------------------
- gen_dp_fifo_sc : FOR i IN 0 TO c_nof_mults-1 GENERATE
- u_dp_fifo_sc : ENTITY dp_lib.dp_fifo_sc
- GENERIC MAP (
- g_data_w => 2*c_acc_data_w,
- g_use_ctrl => FALSE,
- g_use_complex => TRUE,
- g_fifo_size => 64,
- g_fifo_af_margin => 0
- )
- PORT MAP (
- rst => rst,
- clk => clk,
-
- wr_ful => OPEN,
- usedw => OPEN,
- rd_emp => OPEN,
-
- snk_out => OPEN,
- snk_in => dp_fifo_sc_snk_in_arr(i),
- src_in => dp_fifo_sc_src_in_arr(i),
- src_out => dp_fifo_sc_src_out_arr(i)
- );
- END GENERATE;
-
- ------------------------------------------------------------------------------
- -- Read out the FIFOs such that dp_fifo_sc_src_out_arr only carries one valid
- -- word per cycle. This allows folding (multiplexing) into one stream without
- -- losing data (example for 16 streams):
- --
- -- |<--g_nof_invalid_per_valid-->|
- -- 0) [0] [1] ..
- -- 1) | [0] . [1]
- -- 2) | [0] . [1]
- -- 3) | [0] . [1]
- -- 4) | [0] . [1]
- -- 5) | [0] . [1]
- -- 6) | [0] . [1]
- -- 7) | [0] . [1]
- -- 8) | [0] . [1]
- -- 9) | [0] . [1]
- -- 10) | [0] . [1]
- -- 11) | [0] . [1]
- -- 12) | [0] . [1]
- -- 13) | [0] . [1]
- -- 14) | [0] . [1]
- -- 15) |<---g_init_valid_delay(15)-->[0] [1]
- ------------------------------------------------------------------------------
- gen_dp_src_out_timer : FOR i IN 0 TO c_nof_mults-1 GENERATE
- u_dp_src_out_timer : ENTITY dp_lib.dp_src_out_timer
- GENERIC MAP (
- g_init_valid_delay => i, --relative to dp_fifo_sc_src_out_arr(i).valid
- g_nof_invalid_per_valid => c_nof_mults
- )
- PORT MAP (
- rst => rst,
- clk => clk,
-
- init_valid_delay_ref => dp_fifo_sc_snk_in_arr(i).valid,
+ u_corr_visibility_buffer : ENTITY work.corr_visibility_buffer
+ GENERIC MAP (
+ g_nof_inputs => c_nof_mults,
+ g_data_w => c_acc_data_w
+ )
+ PORT MAP (
+ clk => clk,
+ rst => rst,
- snk_in => dp_fifo_sc_src_out_arr(i),
- snk_out => dp_fifo_sc_src_in_arr(i)
- );
- END GENERATE;
+ snk_in_arr => corr_visibility_buffer_snk_in_arr,
+ src_out_arr => corr_visibility_buffer_src_out_arr
+ );
------------------------------------------------------------------------------
-- Fold onto one stream
@@ -274,7 +222,7 @@ BEGIN
rst => rst,
clk => clk,
- snk_in_arr => dp_fifo_sc_src_out_arr,
+ snk_in_arr => corr_visibility_buffer_src_out_arr,
src_out_arr => corr_folder_src_out_arr
);