diff --git a/libraries/base/dp/src/vhdl/dp_packet_unmerge.vhd b/libraries/base/dp/src/vhdl/dp_packet_unmerge.vhd
index 9a8401456e7753a45023be5912ec77afb4eb0af7..26c9f6656e7eab03f42af23ad26e6ce03b71d75e 100644
--- a/libraries/base/dp/src/vhdl/dp_packet_unmerge.vhd
+++ b/libraries/base/dp/src/vhdl/dp_packet_unmerge.vhd
@@ -22,13 +22,21 @@
-- Author: E. Kooistra
-- Purpose: Unmerge each input packet into output packets of length g_pkt_len.
-- Description:
--- . The merged packet length of the snk_in input packets must be an integer
--- multiple of g_pkt_len. The number of output packets g_nof_pkt_max is only
--- used to determine the maximum supported pkt_cnt range. The actual number
--- of output packets has to be <= g_nof_pkt_max, and is determined by input
--- packet length / g_pkt_len. Hence the dp_packet_unmerge can dynamically
--- handle different sizes of input packets, provided that their length is an
--- integer multiple of g_pkt_len.
+-- . The merged packet length of the snk_in input packets is unmerged into
+-- ceil(input packet length / pkt_len). The unmerged output packets have
+-- length pkt_len, but if input packet length mod pkt_len /= 0, then the
+-- last packet will contain the remaining data of the input packet and have
+-- length < pkt_len. Corner cases:
+-- - If pkt_len > input packet length, then the output = input
+-- - The length of the last output packet is input packet length mod
+-- pkt_len, so it can have minimal lenght 1.
+-- . The dynamic pkt_len value is captured at the input eop, or between input
+-- packets, to have a stable value during the unmerge.
+-- . The number of output packets g_nof_pkt is only used to determine the
+-- maximum supported pkt_cnt range. The actual number of output packets has
+-- to be <= g_nof_pkt, and is determined by input packet length /
+-- pkt_len. Hence the dp_packet_unmerge can dynamically handle different
+-- sizes of input packets.
-- . The pkt_cnt is passed on as src_out.channel index.
-- . The g_bsn_increment sets the BSN increment for the unmerged output
-- packets relative to the BSN of the snk_in input packet. When
@@ -51,6 +59,9 @@
--
-- . Optional flow control dependent on g_use_ready and g_pipeline_ready, see
-- description of dp_add_flow_control.
+-- . g_pkt_len statically sets the length of the unmerged packets in absence of
+-- dynamic pkt_len control. When the pkt_len control input is used, g_pkt_len
+-- sets the maximum number length of the unmerged packets.
library IEEE,common_lib;
use IEEE.std_logic_1164.all;
@@ -62,7 +73,7 @@ entity dp_packet_unmerge is
generic (
g_use_ready : boolean := true;
g_pipeline_ready : boolean := false;
- g_nof_pkt_max : natural := 1; -- Maximum nof packets to unmerge each incoming packet to
+ g_nof_pkt : natural := 1; -- Number of packets to unmerge each incoming packet to
g_pkt_len : natural := 1; -- Length of the unmerged packets
g_bsn_increment : natural := 0
);
@@ -70,6 +81,9 @@ entity dp_packet_unmerge is
rst : in std_logic;
clk : in std_logic;
+ pkt_len : in std_logic_vector(ceil_log2(g_pkt_len + 1) - 1 downto 0) := to_uvec(g_pkt_len, ceil_log2(g_pkt_len + 1));
+ pkt_len_out : out std_logic_vector(ceil_log2(g_pkt_len + 1) - 1 downto 0); -- Valid at src_out.sop
+
snk_out : out t_dp_siso;
snk_in : in t_dp_sosi;
@@ -79,20 +93,28 @@ entity dp_packet_unmerge is
end dp_packet_unmerge;
architecture rtl of dp_packet_unmerge is
+ constant c_nof_pkt_max : natural := g_nof_pkt + 1;
+ constant c_pkt_len_max : natural := g_pkt_len + 1;
+ constant c_pkt_len_w : natural := ceil_log2(c_pkt_len_max);
+
-- Internal state of logic function
type t_reg is record
- pkt_cnt : natural range 0 to g_nof_pkt_max + 1;
- val_cnt : natural range 0 to g_pkt_len + 1;
+ pkt_cnt : natural range 0 to c_nof_pkt_max;
+ pkt_len : natural range 0 to c_pkt_len_max;
+ val_cnt : natural range 0 to c_pkt_len_max;
+ busy : std_logic;
src_out : t_dp_sosi;
end record;
- constant c_reg_rst : t_reg := (0, 0, c_dp_sosi_rst);
+ constant c_reg_rst : t_reg := (0, 0, 0, '0', c_dp_sosi_rst);
signal r : t_reg;
signal d : t_reg;
begin
-- Map logic function outputs to entity outputs
+ pkt_len_out <= to_uvec(r.pkt_len, c_pkt_len_w);
+
u_dp_add_flow_control : entity work.dp_add_flow_control
generic map (
g_use_ready => g_use_ready,
@@ -114,19 +136,19 @@ begin
r <= d when rising_edge(clk);
-- Logic function
- p_comb : process(rst, r, snk_in)
+ p_comb : process(rst, r, snk_in, pkt_len)
variable v : t_reg;
begin
-- Default
v := r;
- -- Function
- -- _ _ _
- -- snk_in.sop __| |_______________| |_______________| |_______________|
- -- _ _ _
- -- snk_in.eop _________________| |_______________| |_______________| |_
- -- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
- -- snk_in.valid __|
+ -- Function: unmerge input packet into output packets
+ -- _ _ _
+ -- snk_in.sop __| |_______________| |_______________| |_______________|
+ -- _ _ _
+ -- snk_in.eop _________________| |_______________| |_______________| |_
+ -- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
+ -- snk_in.valid __|
-- v.val_cnt 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
-- v.pkt_cnt 0 1 2 0 1 2 0 1 2
-- ______________ _______________ _______________ _
@@ -154,6 +176,18 @@ begin
v.pkt_cnt := r.pkt_cnt + 1;
end if;
+ -- capture pkt_len between input packets when there is no unmerge busy
+ if snk_in.sop = '1' then
+ v.busy := '1';
+ end if;
+ if snk_in.eop = '1' then
+ v.busy := '0';
+ end if;
+
+ if v.busy = '0' then
+ v.pkt_len := to_uint(pkt_len);
+ end if;
+
-- output packet bsn, sync, sop and eop
-- . Default passes on snk_in.sync, valid, data, re, im
-- . The sync, valid can be passed on from snk_in, without checking
@@ -173,7 +207,12 @@ begin
if v.val_cnt = 0 then
v.src_out.sop := '1';
end if;
- if v.val_cnt = g_pkt_len - 1 then
+ -- Unmerge packets of length r.pkt_len
+ if v.val_cnt = r.pkt_len - 1 then
+ v.src_out.eop := '1';
+ end if;
+ -- Unmerge last packet with length <= r.pkt_len
+ if snk_in.eop = '1' then
v.src_out.eop := '1';
end if;
end if;