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--
-- 8051 compatible microcontroller core
--
-- Version : 0300
--
-- Copyright (c) 2001-2002 Daniel Wallner (jesus@opencores.org)
-- (c) 2004-2005 Andreas Voggeneder (andreas.voggeneder@fh-hagenberg.at)
--
-- All rights reserved
--
-- Redistribution and use in source and synthezised forms, with or without
-- modification, are permitted provided that the following conditions are met:
--
-- Redistributions of source code must retain the above copyright notice,
-- this list of conditions and the following disclaimer.
--
-- Redistributions in synthesized form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution.
--
-- Neither the name of the author nor the names of other contributors may
-- be used to endorse or promote products derived from this software without
-- specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-- POSSIBILITY OF SUCH DAMAGE.
--
-- Please report bugs to the author, but before you do so, please
-- make sure that this is not a derivative work and that
-- you have the latest version of this file.
--
-- The latest version of this file can be found at:
-- http://www.opencores.org/cvsweb.shtml/t51/
--
-- Limitations :
--
-- File history :
--
library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.numeric_std.all;
use WORK.T51_Pack.all;
entity T51_MD is
port(
Clk : in std_logic;
ACC : in std_logic_vector(7 downto 0);
B : in std_logic_vector(7 downto 0);
Mul_Q : out std_logic_vector(15 downto 0);
Mul_OV : out std_logic;
Div_Q : out std_logic_vector(15 downto 0);
Div_OV : out std_logic;
Div_Rdy : out std_logic
);
end T51_MD;
architecture rtl of T51_MD is
signal Old_ACC : std_logic_vector(7 downto 0);
signal Old_B : std_logic_vector(7 downto 0);
begin
process (ACC, B)
variable Tmp : unsigned(15 downto 0);
begin
Tmp := unsigned(ACC) * unsigned(B);
Mul_Q <= std_logic_vector(Tmp);
if Tmp(15 downto 8) = "00000000" then
Mul_OV <= '0';
else
Mul_OV <= '1';
end if;
end process;
process (Clk)
variable Tmp1 : unsigned(15 downto 0);
variable Tmp2 : unsigned(8 downto 0);
variable Tmp3 : unsigned(7 downto 0);
variable Cnt : unsigned(3 downto 0);
begin
if Clk'event and Clk = '1' then
Old_ACC <= ACC;
Old_B <= B;
Div_Rdy <= '0';
Div_OV <= '0';
if Cnt(3) = '1' then
Div_Rdy <= '1';
end if;
if B = "00000000" then
Div_Q <= (others => '-');
Div_OV <= '1';
Div_Rdy <= '1';
elsif ACC = B then
Div_Q(7 downto 0) <= "00000001";
Div_Q(15 downto 8) <= "00000000";
elsif ACC < B then
Div_Q(7 downto 0) <= "00000000";
Div_Q(15 downto 8) <= std_logic_vector(ACC);
Div_Rdy <= '1';
elsif Cnt(3) = '0' then
Tmp1(15 downto 1) := Tmp1(14 downto 0);
Tmp1(0) := '0';
Tmp2 := ("1" & Tmp1(15 downto 8)) - ("0" & Tmp3);
if Tmp2(8) = '1' then
Tmp1(0) := '1';
Tmp1(15 downto 8) := Tmp2(7 downto 0);
end if;
Div_Q <= std_logic_Vector(Tmp1);
end if;
if Old_ACC /= ACC or Old_B /= B then
Tmp1(7 downto 0) := unsigned(ACC);
Tmp1(15 downto 8) := "00000000";
Tmp3 := unsigned(B);
Cnt := "0000";
Div_Rdy <= '0';
else
cnt := cnt + 1;
end if;
end if;
end process;
end;
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