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Rev 7 → Rev 8

/user.vhdl
40,7 → 40,7
For this design, we just need boolean_vector. This is already included in Questa/ModelSim,
but Quartus doesn't yet support this.
*/
use work.types.all;
--use work.types.all;
 
entity user is
generic(
54,7 → 54,7
);
port(
/* Comment-out for simulation. */
clk,reset:in std_ulogic;
-- clk,reset:in std_ulogic;
msg:in unsigned(tapVector'high downto 0):=9x"57";
crc32:out unsigned(31 downto 0):=(others=>'0')
);
/quartus-synthesis/user.vhdl
0,0 → 1,141
/*
This file is part of the Galois Linear Feedback Shift Register
(galois_lfsr) project:
http://www.opencores.org/project,galois_lfsr
Description
Synthesisable use case for Galois LFSR.
This example is a CRC generator that uses a Galois LFSR.
ToDo:
Author(s):
- Daniel C.K. Kho, daniel.kho@opencores.org | daniel.kho@tauhop.com
Copyright (C) 2012-2013 Authors and OPENCORES.ORG
This source file may be used and distributed without
restriction provided that this copyright statement is not
removed from the file and that any derivative work contains
the original copyright notice and the associated disclaimer.
This source file is free software; you can redistribute it
and/or modify it under the terms of the GNU Lesser General
Public License as published by the Free Software Foundation;
either version 2.1 of the License, or (at your option) any
later version.
This source 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 Lesser General Public License for more
details.
You should have received a copy of the GNU Lesser General
Public License along with this source; if not, download it
from http://www.opencores.org/lgpl.shtml.
*/
library ieee; use ieee.std_logic_1164.all, ieee.numeric_std.all; use ieee.math_real.all;
/* Enable for synthesis; comment out for simulation.
For this design, we just need boolean_vector. This is already included in Questa/ModelSim,
but Quartus doesn't yet support this.
*/
use work.types.all;
 
entity user is
generic(
parallelLoad:boolean:=false;
tapVector:boolean_vector:=(
/* Example polynomial from Wikipedia:
http://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks
*/
0|1|2|8=>true, 7 downto 3=>false
)
);
port(
/* Comment-out for simulation. */
clk,reset:in std_ulogic;
msg:in unsigned(tapVector'high downto 0):=9x"57";
crc32:out unsigned(31 downto 0):=(others=>'0')
);
end entity user;
 
architecture rtl of user is
signal n,c:natural;
/* Tester signals. */
signal d:std_ulogic;
/* synthesis translate_off */
signal clk,reset:std_ulogic:='0';
/* synthesis translate_on */
signal loadEn,computeClk:std_ulogic; -- clock gating.
signal loaded,i_loaded:boolean;
signal computed,i_computed:boolean;
begin
/* Simulation Tester. */
/* synthesis translate_off */
clk<=not clk after 10 ps;
process is begin
reset<='0'; wait for 1 ps;
reset<='1'; wait for 500 ps;
reset<='0';
wait;
end process;
/* synthesis translate_on */
loadEn<=clk when reset='0' and not i_computed else '0';
computeClk<=clk when reset='0' and i_loaded and not i_computed else '0';
/* Galois LFSR instance. */
i_lfsr: entity work.lfsr(rtl)
generic map(taps=>tapVector)
/*generic map(taps => (
0|1|2|8=>true,
7 downto 3=>false
))*/
port map(nReset=>not reset, clk=>loadEn,
load=>parallelLoad,
seed=>msg,
d=>d,
q=>crc32(msg'range)
);
/* Load message into LFSR. */
process(reset,loadEn) is begin
if reset then loaded<=false; n<=msg'length-1; d<='0';
elsif rising_edge(loadEn) then
d<='0';
/* for parallel mode, LFSR automatically loads the seed in parallel. */
if parallelLoad then d<='0'; loaded<=true;
else
if not loaded then d<=msg(n); end if;
if n>0 then n<=n-1;
else loaded<=true;
end if;
end if;
end if;
end process;
/* Shift zeroes into LFSR after message has been loaded completely. */
process(reset,loaded,computeClk) is begin
if reset='1' or not loaded then computed<=false; c<=msg'length-1;
elsif rising_edge(computeClk) then
if c>0 then c<=c-1;
else computed<=true;
end if;
end if;
end process;
/* Register pipelines. */
process(clk) is begin
if falling_edge(clk) then
i_loaded<=loaded;
i_computed<=computed;
end if;
end process;
end architecture rtl;
quartus-synthesis/user.vhdl Property changes : Added: svn:executable ## -0,0 +1 ## +* \ No newline at end of property Index: quartus-synthesis/galois-lfsr.vhdl =================================================================== --- quartus-synthesis/galois-lfsr.vhdl (nonexistent) +++ quartus-synthesis/galois-lfsr.vhdl (revision 8) @@ -0,0 +1,96 @@ +/* + This file is part of the Galois-type linear-feedback shift register + (galois_lfsr) project: + http://www.opencores.org/project,galois_lfsr + + Description + Synthesisable use case for Galois LFSR. + This example is a CRC generator that uses a Galois LFSR. + Example applications include: + * serial or parallel PRBS generation. + * CRC computation. + * digital scramblers/descramblers. + + ToDo: + + Author(s): + - Daniel C.K. Kho, daniel.kho@opencores.org | daniel.kho@tauhop.com + + Copyright (C) 2012-2013 Authors and OPENCORES.ORG + + This source file may be used and distributed without + restriction provided that this copyright statement is not + removed from the file and that any derivative work contains + the original copyright notice and the associated disclaimer. + + This source file is free software; you can redistribute it + and/or modify it under the terms of the GNU Lesser General + Public License as published by the Free Software Foundation; + either version 2.1 of the License, or (at your option) any + later version. + + This source 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 Lesser General Public License for more + details. + + You should have received a copy of the GNU Lesser General + Public License along with this source; if not, download it + from http://www.opencores.org/lgpl.shtml. +*/ +library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all; +/* Enable for synthesis; comment out for simulation. + For this design, we just need boolean_vector. This is already included in Questa/ModelSim, + but Quartus doesn't yet support this. +*/ +use work.types.all; + +entity lfsr is generic( + /* + * Tap vector: a TRUE means that position is tapped, otherwise that position is untapped. + */ + taps:boolean_vector + ); + + port(nReset,clk:in std_ulogic:='0'; + load:in boolean; + seed:in unsigned(taps'high downto 0); + + d:in std_ulogic; + q:out unsigned(taps'high downto 0) + ); +end entity lfsr; + +architecture rtl of lfsr is + signal i_d,i_q:unsigned(taps'high downto 0); + signal x:unsigned(taps'high-1 downto 0); + +begin +-- /* [begin]: Simulation testbench stimuli. Do not remove. +-- TODO migrate to separate testbench when more testcases are developed. +-- */ +-- /* synthesis translate_off */ +-- clk<=not clk after 1 ns; +-- /* synthesis translate_on */ +-- /* [end]: simulation stimuli. */ + + + /* Receives a vector of taps; generates LFSR structure with correct XOR positionings. */ + tapGenr: for i in 0 to taps'high-1 generate + i_d(i+1)<=x(i) when taps(i) else i_q(i); + x(i)<=i_q(i) xor i_q(taps'high); + end generate; + + process(nReset,load,seed,clk) is begin + if nReset='0' then i_q<=(others=>'0'); + elsif load then i_q<=seed; + elsif rising_edge(clk) then + i_q<=i_d; + end if; + end process; + + i_d(0)<=d; + q<=i_d; + +end architecture rtl;
quartus-synthesis/galois-lfsr.vhdl Property changes : Added: svn:executable ## -0,0 +1 ## +* \ No newline at end of property Index: galois-lfsr.vhdl =================================================================== --- galois-lfsr.vhdl (revision 7) +++ galois-lfsr.vhdl (revision 8) @@ -1,5 +1,5 @@ /* - This file is part of the Galois Linear Feedback Shift Register + This file is part of the Galois-type linear-feedback shift register (galois_lfsr) project: http://www.opencores.org/project,galois_lfsr @@ -44,7 +44,7 @@ For this design, we just need boolean_vector. This is already included in Questa/ModelSim, but Quartus doesn't yet support this. */ -use work.types.all; +--use work.types.all; entity lfsr is generic( /*

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