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Commit 2a8f137b authored by Reinier van der Walle's avatar Reinier van der Walle
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Improved dp_fifo_fill_eop to handle continious streams without gaps

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libraries/base/dp/src/vhdl/dp_fifo_fill_eop.vhd
+ 128
− 242
View file @ 2a8f137b
......@@ -32,10 +32,6 @@
-- after the fifo has been filled sufficiently, a frame is also available when
-- the in_eop has been received earlier than the specified g_fifo_fill. For
-- more details, please consult the description of dp_fill_fifo_core.
-- Remark:
-- . dp_fifo_fill_eop needs 1 clock cycle gap between eop and sop to process
-- the block. Therefore it cannot handle contious streams without gaps. It
-- can handle bursts by increasing g_fifo_size.
-------------------------------------------------------------------------------
LIBRARY IEEE, common_lib, technology_lib;
......@@ -48,6 +44,7 @@ USE technology_lib.technology_select_pkg.ALL;
ENTITY dp_fifo_fill_eop IS
GENERIC (
g_technology : NATURAL := c_tech_select_default;
g_note_is_ful : BOOLEAN := TRUE;
g_use_dual_clock : BOOLEAN := FALSE;
g_data_w : NATURAL := 16;
g_bsn_w : NATURAL := 1;
......@@ -99,16 +96,12 @@ ARCHITECTURE rtl OF dp_fifo_fill_eop IS
CONSTANT c_use_ctrl : BOOLEAN := TRUE;
-- Define t_state as slv to avoid Modelsim warning "Nonresolved signal 'nxt_state' may have multiple sources". Due to that g_fifo_rl = 0 or 1 ar both supported.
--TYPE t_state IS (s_idle, s_fill, s_output, s_xoff);
CONSTANT s_idle : STD_LOGIC_VECTOR(1 DOWNTO 0) := "00";
CONSTANT s_fill : STD_LOGIC_VECTOR(1 DOWNTO 0) := "01";
CONSTANT s_output : STD_LOGIC_VECTOR(1 DOWNTO 0) := "10";
CONSTANT s_xoff : STD_LOGIC_VECTOR(1 DOWNTO 0) := "11";
TYPE t_state IS (s_fill, s_output, s_xoff);
CONSTANT c_nof_spulse : NATURAL := 3;
SIGNAL state : STD_LOGIC_VECTOR(1 DOWNTO 0); -- t_state
SIGNAL nxt_state : STD_LOGIC_VECTOR(1 DOWNTO 0); -- t_state
SIGNAL state : t_state;
SIGNAL nxt_state : t_state;
SIGNAL xon_reg : STD_LOGIC;
SIGNAL nxt_xon_reg : STD_LOGIC;
......@@ -150,13 +143,13 @@ BEGIN
-- Control FIFO fill level
wr_usedw_32b <= RESIZE_UVEC(wr_fifo_usedw, c_word_w);
rd_usedw_32b <= RESIZE_UVEC(rd_fifo_usedw, c_word_w);
rd_fill_ctrl <= rd_fill_32b(c_fifo_size_w-1 DOWNTO 0);
gen_dp_fifo_sc : IF g_use_dual_clock=FALSE GENERATE
u_dp_fifo_sc : ENTITY work.dp_fifo_sc
u_dp_fifo_core : ENTITY work.dp_fifo_core
GENERIC MAP (
g_technology => g_technology,
g_note_is_ful => g_note_is_ful,
g_use_dual_clock => g_use_dual_clock,
g_data_w => g_data_w,
g_bsn_w => g_bsn_w,
g_empty_w => g_empty_w,
......@@ -173,62 +166,6 @@ BEGIN
g_fifo_af_margin => g_fifo_af_margin,
g_fifo_rl => c_fifo_rl
)
PORT MAP (
rst => rd_rst,
clk => rd_clk,
-- Monitor FIFO filling
wr_ful => wr_ful,
usedw => rd_fifo_usedw,
rd_emp => rd_emp,
-- ST sink
snk_out => snk_out,
snk_in => snk_in,
-- ST source
src_in => rd_siso, -- for RL = 0 rd_siso.ready acts as read acknowledge, for RL = 1 rd_siso.ready acts as read request
src_out => rd_sosi
);
wr_fifo_usedw <= rd_fifo_usedw;
-- No need to transfer eop counter across clock domains
rd_eop_cnt <= wr_eop_cnt;
rd_eop_new <= '1';
p_sc: PROCESS(wr_clk, wr_rst)
BEGIN
IF wr_rst='1' THEN
wr_eop_cnt <= 0;
ELSIF rising_edge(wr_clk) THEN
IF snk_in.eop = '1' THEN
wr_eop_cnt <= 1;
ELSE
wr_eop_cnt <= 0;
END IF;
END IF;
END PROCESS;
END GENERATE;
gen_dp_fifo_dc : IF g_use_dual_clock=TRUE GENERATE
u_dp_fifo_dc : ENTITY work.dp_fifo_dc
GENERIC MAP (
g_technology => g_technology,
g_data_w => g_data_w,
g_bsn_w => g_bsn_w,
g_empty_w => g_empty_w,
g_channel_w => g_channel_w,
g_error_w => g_error_w,
g_use_bsn => g_use_bsn,
g_use_empty => g_use_empty,
g_use_channel => g_use_channel,
g_use_error => g_use_error,
g_use_sync => g_use_sync,
g_use_ctrl => c_use_ctrl,
--g_use_complex => g_use_complex,
g_fifo_size => c_fifo_size,
g_fifo_af_margin => g_fifo_af_margin,
g_fifo_rl => c_fifo_rl
)
PORT MAP (
wr_rst => wr_rst,
wr_clk => wr_clk,
......@@ -247,9 +184,9 @@ BEGIN
src_out => rd_sosi
);
-- Transfer eop counter across clock domains
-- Transfer eop counter across clock domains for dual clock
gen_dp_fifo_dc : IF g_use_dual_clock=TRUE GENERATE
reg_wr_eop_cnt <= TO_UVEC(wr_eop_cnt, c_word_w);
rd_eop_cnt <= TO_UINT(reg_rd_eop_cnt);
u_common_reg_cross_domain : ENTITY common_lib.common_reg_cross_domain
PORT MAP (
in_rst => wr_rst,
......@@ -262,8 +199,17 @@ BEGIN
out_dat => reg_rd_eop_cnt,
out_new => rd_eop_new
);
END GENERATE;
p_dc: PROCESS(wr_clk, wr_rst)
-- No need to transfer eop counter across clock domains for single clock
gen_dp_fifo_sc : IF g_use_dual_clock=FALSE GENERATE
wr_fifo_usedw <= rd_fifo_usedw;
rd_eop_new <= '1';
END GENERATE;
rd_eop_cnt <= TO_UINT(reg_rd_eop_cnt) WHEN g_use_dual_clock ELSE wr_eop_cnt;
p_eop_cnt: PROCESS(wr_clk, wr_rst)
VARIABLE v_wr_eop_cnt: NATURAL;
BEGIN
IF wr_rst='1' THEN
......@@ -271,6 +217,7 @@ BEGIN
wr_eop_cnt <= 0;
wr_eop_new <= '0';
ELSIF rising_edge(wr_clk) THEN
IF g_use_dual_clock THEN -- transfer eop counter accross clock domains
v_wr_eop_cnt := wr_eop_cnt;
IF wr_eop_done = '1' THEN
wr_eop_busy <= '0';
......@@ -290,9 +237,21 @@ BEGIN
v_wr_eop_cnt := v_wr_eop_cnt + 1;
END IF;
wr_eop_cnt <= v_wr_eop_cnt;
ELSE -- No need to transfer eop counter across clock domains for single clock
IF wr_rst='1' THEN
wr_eop_cnt <= 0;
ELSIF rising_edge(wr_clk) THEN
IF snk_in.eop = '1' THEN
wr_eop_cnt <= 1;
ELSE
wr_eop_cnt <= 0;
END IF;
END IF;
END IF;
END IF;
END PROCESS;
END GENERATE;
no_fill : IF g_fifo_fill=0 GENERATE
rd_siso <= src_in; -- SISO
......@@ -307,7 +266,7 @@ BEGIN
BEGIN
IF rd_rst='1' THEN
xon_reg <= '0';
state <= s_idle;
state <= s_fill;
i_src_out <= c_dp_sosi_rst;
eop_cnt <= 0;
ELSIF rising_edge(rd_clk) THEN
......@@ -320,77 +279,6 @@ BEGIN
nxt_xon_reg <= src_in.xon; -- register xon to easy timing closure
gen_rl_0 : IF g_fifo_rl=0 GENERATE
p_state : PROCESS(state, rd_sosi, src_in, xon_reg, rd_fifo_usedw, rd_fill_ctrl, rd_eop_cnt, eop_cnt, rd_eop_new)
BEGIN
nxt_state <= state;
rd_siso <= src_in; -- default acknowledge (RL=1) this input when output is ready
-- The output register stage increase RL=0 to 1, so it matches RL = 1 for src_in.ready
nxt_src_out <= rd_sosi;
nxt_src_out.valid <= '0'; -- default no output
nxt_src_out.sop <= '0';
nxt_src_out.eop <= '0';
nxt_src_out.sync <= '0';
nxt_eop_cnt <= eop_cnt;
IF rd_eop_new = '1' THEN
nxt_eop_cnt <= eop_cnt + rd_eop_cnt;
END IF;
CASE state IS
WHEN s_idle =>
IF xon_reg='0' THEN
nxt_state <= s_xoff;
ELSE
-- read the FIFO until the sop is pending at the output, so discard any valid data between eop and sop
IF rd_sosi.sop='0' THEN
rd_siso <= c_dp_siso_rdy; -- acknowledge (RL=0) this input independent of output ready
ELSE
rd_siso <= c_dp_siso_hold; -- stop the input, hold the rd_sosi.sop at FIFO output (RL=0)
nxt_state <= s_fill;
END IF;
END IF;
WHEN s_fill =>
IF xon_reg='0' THEN
nxt_state <= s_xoff;
ELSE
-- stop reading until the FIFO has been filled sufficiently
IF UNSIGNED(rd_fifo_usedw)<UNSIGNED(rd_fill_ctrl) AND eop_cnt <= 0 THEN
rd_siso <= c_dp_siso_hold; -- stop the input, hold the pend_src_out.sop
ELSE
-- if the output is ready, then start outputting the frame
IF src_in.ready='1' THEN
nxt_src_out <= rd_sosi; -- output sop that is still at FIFO output (RL=0)
nxt_state <= s_output;
IF rd_eop_new = '1' THEN
nxt_eop_cnt <= eop_cnt + rd_eop_cnt - 1;
ELSE
nxt_eop_cnt <= eop_cnt -1;
END IF;
END IF;
END IF;
END IF;
WHEN s_output =>
-- if the output is ready continue outputting the frame, ignore xon_reg during this frame
IF src_in.ready='1' THEN
nxt_src_out <= rd_sosi; -- output valid
IF rd_sosi.eop='1' THEN
nxt_state <= s_idle; -- output eop, so stop reading the FIFO
END IF;
END IF;
WHEN OTHERS => -- s_xoff
-- Flush the fill FIFO when xon='0'
rd_siso <= c_dp_siso_flush;
IF xon_reg='1' THEN
nxt_state <= s_idle;
END IF;
END CASE;
-- Pass on frame level flow control
rd_siso.xon <= src_in.xon;
END PROCESS;
END GENERATE; -- gen_rl_0
gen_rl_1 : IF g_fifo_rl=1 GENERATE
-- Use dp_hold_input to get equivalent implementation with default RL=1 FIFO.
......@@ -408,6 +296,13 @@ BEGIN
pend_src_out => pend_src_out,
src_out_reg => i_src_out
);
END GENERATE;
gen_rl_0 : IF g_fifo_rl=0 GENERATE
pend_src_out <= rd_sosi;
rd_siso <= hold_src_in;
END GENERATE;
p_state : PROCESS(state, src_in, xon_reg, pend_src_out, rd_fifo_usedw, rd_fill_ctrl, rd_eop_cnt, eop_cnt, rd_eop_new)
BEGIN
......@@ -427,7 +322,7 @@ BEGIN
END IF;
CASE state IS
WHEN s_idle =>
WHEN s_fill =>
IF xon_reg='0' THEN
nxt_state <= s_xoff;
ELSE
......@@ -435,15 +330,6 @@ BEGIN
IF pend_src_out.sop='0' THEN
hold_src_in <= c_dp_siso_rdy; -- request (RL=1) new input independent of output ready
ELSE
hold_src_in <= c_dp_siso_hold; -- stop the input, hold the pend_src_out.sop in dp_hold_input
nxt_state <= s_fill;
END IF;
END IF;
WHEN s_fill =>
IF xon_reg='0' THEN
nxt_state <= s_xoff;
ELSE
-- stop reading until the FIFO has been filled sufficiently
IF UNSIGNED(rd_fifo_usedw)<UNSIGNED(rd_fill_ctrl) AND eop_cnt <= 0 THEN
hold_src_in <= c_dp_siso_hold; -- stop the input, hold the pend_src_out.sop
ELSE
......@@ -459,26 +345,26 @@ BEGIN
END IF;
END IF;
END IF;
END IF;
WHEN s_output =>
-- if the output is ready continue outputting the input frame, ignore xon_reg during this frame
IF src_in.ready='1' THEN
nxt_src_out <= pend_src_out; -- output valid
IF pend_src_out.eop='1' THEN
nxt_state <= s_idle; -- output eop, so stop reading the FIFO
nxt_state <= s_fill; -- output eop, so stop reading the FIFO
END IF;
END IF;
WHEN OTHERS => -- s_xon
WHEN OTHERS => -- s_xoff
-- Flush the fill FIFO when xon='0'
hold_src_in <= c_dp_siso_flush;
IF xon_reg='1' THEN
nxt_state <= s_idle;
nxt_state <= s_fill;
END IF;
END CASE;
-- Pass on frame level flow control
hold_src_in.xon <= src_in.xon;
END PROCESS;
END GENERATE; -- gen_rl_1
END GENERATE; -- gen_fill
END rtl;
libraries/base/dp/tb/vhdl/tb_tb_dp_fifo_fill_eop.vhd
+ 4
− 2
View file @ 2a8f137b
......@@ -46,7 +46,9 @@ ARCHITECTURE tb OF tb_tb_dp_fifo_fill_eop IS
SIGNAL tb_end : STD_LOGIC := '0'; -- declare tb_end to avoid 'No objects found' error on 'when -label tb_end'
BEGIN
-- Try FIFO settings : GENERIC MAP (g_dut_use_dual_clock, g_dut_use_bsn, g_dut_use_empty, g_dut_use_channel, g_dut_use_sync, g_dut_fifo_rl, g_dut_fifo_size, g_dut_fifo_fill, g_dut_use_rd_fill_32b)
u_dut_sc : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => FALSE);
u_dut_dc : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => TRUE);
u_dut_sc_1 : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => FALSE, g_dut_fifo_rl => 1);
u_dut_dc_1 : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => TRUE, g_dut_fifo_rl => 1);
u_dut_sc_0 : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => FALSE, g_dut_fifo_rl => 0);
u_dut_dc_0 : ENTITY work.tb_dp_fifo_fill_eop GENERIC MAP (g_dut_use_dual_clock => TRUE, g_dut_fifo_rl => 0);
END tb;
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