From e158fc6c293e8ab4ebc16b647c5a68c8cb04acd8 Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Thu, 21 Sep 2023 09:34:04 +0200
Subject: [PATCH] Correct use of v_busy and rst value.
---
.../base/dp/src/vhdl/dp_packet_merge.vhd | 74 +++++++++----------
1 file changed, 37 insertions(+), 37 deletions(-)
diff --git a/libraries/base/dp/src/vhdl/dp_packet_merge.vhd b/libraries/base/dp/src/vhdl/dp_packet_merge.vhd
index 14dfd8a984..2de0853cc9 100644
--- a/libraries/base/dp/src/vhdl/dp_packet_merge.vhd
+++ b/libraries/base/dp/src/vhdl/dp_packet_merge.vhd
@@ -46,6 +46,8 @@
-- . with g_align_at_sync=true the merge can be forced to restart at a snk_in.sync.
-- . Optional flow control dependent on g_use_ready and g_pipeline_ready, see
-- description of dp_add_flow_control.
+-- . The input packets do not have to have equal length, because they are
+-- merged based on counting their eop.
library IEEE,common_lib;
@@ -67,7 +69,7 @@ entity dp_packet_merge is
rst : in std_logic;
clk : in std_logic;
- nof_pkt : in std_logic_vector(ceil_log2(g_nof_pkt + 1) - 1 downto 0) := TO_UVEC(g_nof_pkt, ceil_log2(g_nof_pkt + 1));
+ nof_pkt : in std_logic_vector(ceil_log2(g_nof_pkt + 1) - 1 downto 0) := to_uvec(g_nof_pkt, ceil_log2(g_nof_pkt + 1));
nof_pkt_out : out std_logic_vector(ceil_log2(g_nof_pkt + 1) - 1 downto 0); -- Valid at src_out.sop
snk_out : out t_dp_siso;
@@ -79,10 +81,13 @@ entity dp_packet_merge is
end dp_packet_merge;
architecture rtl of dp_packet_merge is
+ constant c_nof_pkt_max : natural := g_nof_pkt + 1;
+ constant c_nof_pkt_w : natural := ceil_log2(c_nof_pkt_max);
+
type t_reg is record
- nof_pkt : natural range 0 to g_nof_pkt + 1;
- pkt_cnt : natural range 0 to g_nof_pkt + 1;
- align_cnt : natural range 0 to g_nof_pkt + 1;
+ nof_pkt : natural range 0 to c_nof_pkt_max;
+ pkt_cnt : natural range 0 to c_nof_pkt_max;
+ align_cnt : natural range 0 to c_nof_pkt_max;
busy : std_logic;
sync : std_logic;
next_bsn : std_logic_vector(c_dp_stream_bsn_w - 1 downto 0);
@@ -90,10 +95,12 @@ architecture rtl of dp_packet_merge is
src_out : t_dp_sosi;
end record;
+ constant c_reg_rst : t_reg := (0, 0, 0, '0', '0', (others =>'0'), '0', c_dp_sosi_rst);
+
signal r, nxt_r : t_reg;
begin
-- Map logic function outputs to entity outputs
- nof_pkt_out <= TO_UVEC(r.nof_pkt, ceil_log2(g_nof_pkt + 1));
+ nof_pkt_out <= to_uvec(r.nof_pkt, c_nof_pkt_w);
u_dp_add_flow_control : entity work.dp_add_flow_control
generic map (
@@ -124,7 +131,7 @@ begin
v := r;
----------------------------------------------------------------------------
- -- Function
+ -- Function: merge input packets into one output packet
-- _ _ _ _ _ _ _ _ _
-- snk_in.sop _____|0|_______|1|_______|2|_______|0|_______|1|_______|2|__________|0|_______|1|_______|2|_______
-- _ _ _ _ _ _ _ _ _
@@ -150,29 +157,6 @@ begin
end if;
end if;
- -- capture nof_pkt between output packets when there is no merge busy
- if snk_in.sop = '1' then
- v.busy := '1';
- end if;
- if snk_in.eop = '1' then
- if r.pkt_cnt = r.nof_pkt - 1 then
- v.busy := '0';
- end if;
- end if;
-
- if g_align_at_sync then
- if snk_in.sync = '1' then
- if r.pkt_cnt > 0 then
- v.align_cnt := r.nof_pkt - r.pkt_cnt; -- = 0 when sync occurs at integer number of merged blocks, > 0 when (re)align to sync is needed
- end if;
- end if;
- end if;
-
- if v.busy = '0' and v.src_out.eop = '1' then
- v.nof_pkt := TO_UINT(nof_pkt) - r.align_cnt; -- use shorter next merge to (re)align to sync (when g_align_at_sync=false then r.align_cnt=0)
- v.align_cnt := 0;
- end if;
-
-- output packet bsn, sync, sop and eop
v.src_out := snk_in;
v.src_out.bsn := r.src_out.bsn;
@@ -222,6 +206,29 @@ begin
end if;
end if;
+ -- capture nof_pkt between output packets when there is no merge busy
+ -- . For determining busy, using snk_in.sop is functionally equivalent to
+ -- using v.src_out.sop, but using snk_in.sop may ease timing closure.
+ if snk_in.sop = '1' then
+ v.busy := '1';
+ end if;
+ if v.src_out.eop = '1' then
+ v.busy := '0';
+ end if;
+
+ if g_align_at_sync then
+ if snk_in.sync = '1' then
+ if r.pkt_cnt > 0 then
+ v.align_cnt := r.nof_pkt - r.pkt_cnt; -- = 0 when sync occurs at integer number of merged blocks, > 0 when (re)align to sync is needed
+ end if;
+ end if;
+ end if;
+
+ if v.busy = '0' then
+ v.nof_pkt := TO_UINT(nof_pkt) - r.align_cnt; -- use shorter next merge to (re)align to sync (when g_align_at_sync=false then r.align_cnt=0)
+ v.align_cnt := 0;
+ end if;
+
-- force sosi control to inactive for no output when nof_pkt=0
if r.nof_pkt = 0 then
v.src_out.valid := '0';
@@ -234,14 +241,7 @@ begin
----------------------------------------------------------------------------
-- Reset and nxt_r
if rst = '1' then
- v.nof_pkt := TO_UINT(nof_pkt);
- v.pkt_cnt := 0;
- v.align_cnt := 0;
- v.busy := '0';
- v.sync := '0';
- v.next_bsn := (others => '0');
- v.bsn_err := '0';
- v.src_out := c_dp_sosi_rst;
+ v := c_reg_rst;
end if;
nxt_r <= v;
--
GitLab