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    i_dataa <= (dataa(lpm_width) & dataa);
    i_datab <= (datab(lpm_width) & datab);

-- PROCESS DECLARATION

    -- basic error checking for invalid parameters
    MSG: process
    begin
        if (lpm_width <= 0) then
            ASSERT FALSE
            REPORT "Value of lpm_width parameter must be greater than 0!"
            SEVERITY ERROR;
        end if;

        if (lpm_pipeline < 0) then
            ASSERT FALSE
            REPORT "Value of lpm_pipeline parameter must be greater than or equal to 0!"
            SEVERITY ERROR;
        end if;
        wait;
    end process MSG;

    process(aclr, clock, i_dataa, i_datab, cin, add_sub)
    variable resulttmp : T_RESULTTMP := (OTHERS => (OTHERS => '0'));
    variable couttmp : std_logic_vector(0 to lpm_pipeline) := (OTHERS => '0');
    variable overflowtmp : std_logic_vector(0 to lpm_pipeline) := (OTHERS => '0');
    variable i_cin : std_logic;
    begin
        if (lpm_pipeline >= 0) then
            if ((lpm_direction = "ADD") or
               ((lpm_direction = "UNUSED") and (add_sub = '1'))) then
                if (cin = 'Z') then
                    i_cin := '0';
                else
                    i_cin := cin;
                end if;

                -- Perform as adder
                resulttmp(lpm_pipeline) := i_dataa + i_datab + i_cin;
                couttmp(lpm_pipeline) := resulttmp(lpm_pipeline)(lpm_width) xor
                                         dataa(lpm_width) xor
                                         datab(lpm_width);
                                         
                if ((dataa(lpm_width) = '0') and (datab(lpm_width) = '0') and 
                    (resulttmp(lpm_pipeline)(lpm_width-1) = '1'))  or
                    ((dataa(lpm_width) = '1') and (datab(lpm_width) = '1') and 
                    (resulttmp(lpm_pipeline)(lpm_width-1) = '0')) then
                    overflowtmp(lpm_pipeline) := '1';   
                else
                    overflowtmp(lpm_pipeline) := '0';
                end if;
            elsif ((lpm_direction = "SUB") or
                  ((lpm_direction = "UNUSED") and (add_sub = '0'))) then
                if (cin = 'Z') then
                    i_cin := '1';
                else
                    i_cin := cin;
                end if;

                -- Perform as subtrator
                resulttmp(lpm_pipeline) := i_dataa - i_datab + i_cin - 1;
                couttmp(lpm_pipeline) := (not resulttmp(lpm_pipeline)(lpm_width)) xor
                                          dataa(lpm_width) xor
                                          datab(lpm_width);
                                          
                if ((dataa(lpm_width) = '0') and (datab(lpm_width) = '1') and 
                    (resulttmp(lpm_pipeline)(lpm_width-1) = '1'))  or
                    ((dataa(lpm_width) = '1') and (datab(lpm_width) = '0') and 
                    (resulttmp(lpm_pipeline)(lpm_width-1) = '0')) then
                    overflowtmp(lpm_pipeline) := '1';   
                else
                    overflowtmp(lpm_pipeline) := '0';
                end if;
            elsif (lpm_direction /= "UNUSED") then
                ASSERT FALSE
                REPORT "Illegal lpm_direction property value for LPM_ADD_SUB!"
                SEVERITY ERROR;
            end if;
            
            if (lpm_pipeline > 0) then  -- Pipeline the result
                if (aclr = '1') then
                    overflowtmp := (OTHERS => '0');
                    couttmp := (OTHERS => '0');
                    for i in 0 to lpm_pipeline loop
                        resulttmp(i) := (OTHERS => '0');
                    end loop;
                elsif (clock'event and (clock = '1') and (clken = '1')) then
                    overflowtmp(0 to lpm_pipeline - 1) := overflowtmp(1 to lpm_pipeline);
                    couttmp(0 to lpm_pipeline - 1) := couttmp(1 to lpm_pipeline);
                    resulttmp(0 to lpm_pipeline - 1) := resulttmp(1 to lpm_pipeline);
                end if;
            end if;

            -- send the pipeline result to output ports
            cout <= couttmp(0);
            overflow <= overflowtmp(0);
            result <= resulttmp(0)(lpm_width-1 downto 0);
        end if;
    end process;

end LPM_SYN;
-- END OF ARCHITECTURE


---START_ENTITY_HEADER---------------------------------------------------------
--
-- Entity Name     :  lpm_add_sub_unsigned
--
-- Description     :  This entity is instiatiated by lpm_add_sub megafunction to perform
--                    adder/subtrator function for unsigned number.
--
-- Limitation      :  n/a
--
-- Results Expected:  If performs as adder, the result will be dataa[]+datab[]+cin.
--                    If performs as subtractor, the result will be dataa[]-datab[]+cin-1.
--                    Also returns carry out bit and overflow status bit.
--
---END_ENTITY_HEADER-----------------------------------------------------------

-- LIBRARY USED----------------------------------------------------------------
library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
use work.LPM_COMPONENTS.all;

-- ENTITY DECLARATION
entity LPM_ADD_SUB_UNSIGNED is
    generic (
        lpm_width      : natural;    -- MUST be greater than 0
        lpm_direction  : string  := "UNUSED";
        lpm_pipeline   : natural := 0;
        lpm_type       : string  := "LPM_ADD_SUB";
        lpm_hint       : string  := "UNUSED"
    );
    
    port (
        dataa   : in std_logic_vector(lpm_width-1 downto 0);
        datab   : in std_logic_vector(lpm_width-1 downto 0);
        cin     : in std_logic := 'Z';
        add_sub : in std_logic := '1';
        clock   : in std_logic := '0';
        aclr    : in std_logic := '0';
        clken   : in std_logic := '1';
        result   : out std_logic_vector(lpm_width-1 downto 0);
        cout     : out std_logic;
        overflow : out std_logic
    );
end LPM_ADD_SUB_UNSIGNED;
-- END OF ENTITY

-- BEGINNING OF ARCHITECTURE
architecture LPM_SYN of LPM_ADD_SUB_UNSIGNED is

-- SIGNAL DECLARATION
signal i_dataa, i_datab : std_logic_vector(lpm_width downto 0);

-- TYPE DECLARATION
type T_RESULTTMP IS ARRAY (0 to lpm_pipeline) of std_logic_vector(lpm_width downto 0);

begin

    i_dataa <= ('0' & dataa);
    i_datab <= ('0' & datab);

-- PROCESS DECLARATION

    -- basic error checking for invalid parameters
    MSG: process
    begin
        if (lpm_width <= 0) then
            ASSERT FALSE
            REPORT "Value of lpm_width parameter must be greater than 0!"
            SEVERITY ERROR;
        end if;

        if (lpm_pipeline < 0) then
            ASSERT FALSE
            REPORT "Value of lpm_pipeline parameter must be greater than or equal to 0!"
            SEVERITY ERROR;
        end if;
        wait;
    end process MSG;

    process(aclr, clock, i_dataa, i_datab, cin, add_sub)
    variable resulttmp   : T_RESULTTMP := (OTHERS => (OTHERS => '0'));
    variable couttmp     : std_logic_vector(0 to lpm_pipeline) := (OTHERS => '0');
    variable overflowtmp : std_logic_vector(0 to lpm_pipeline) := (OTHERS => '0');
    variable i_cin       : std_logic;
    begin

        if (lpm_pipeline >= 0) then
            if ((lpm_direction = "ADD") or
               ((lpm_direction = "UNUSED") and (add_sub = '1'))) then
                if (cin = 'Z') then
                    i_cin := '0';
                else
                    i_cin := cin;
                end if;

                -- Perform as adder
                resulttmp(lpm_pipeline) := i_dataa + i_datab + i_cin;
                couttmp(lpm_pipeline)   := resulttmp(lpm_pipeline)(lpm_width);
            elsif ((lpm_direction = "SUB") or
                  ((lpm_direction = "UNUSED") and (add_sub = '0'))) then
                if (cin = 'Z') then
                    i_cin := '1';
                else
                    i_cin := cin;
                end if;

                -- Perform as subtractor
                resulttmp(lpm_pipeline) := i_dataa - i_datab + i_cin - 1;
                couttmp(lpm_pipeline)   := not resulttmp(lpm_pipeline)(lpm_width);
            elsif (lpm_direction /= "UNUSED") then
                ASSERT FALSE
                REPORT "Illegal lpm_direction property value for LPM_ADD_SUB!"
                SEVERITY ERROR;
            end if;

            overflowtmp(lpm_pipeline) := resulttmp(lpm_pipeline)(lpm_width);

            if (lpm_pipeline > 0) then -- Pipeline the result
                if (aclr = '1') then
                    overflowtmp := (OTHERS => '0');
                    couttmp := (OTHERS => '0');
                    for i in 0 to lpm_pipeline loop
                        resulttmp(i) := (OTHERS => '0');
                    end loop;
                elsif (clock'event and (clock = '1') and (clken = '1')) then
                    overflowtmp(0 to lpm_pipeline - 1) := overflowtmp(1 to lpm_pipeline);
                    couttmp(0 to lpm_pipeline - 1) := couttmp(1 to lpm_pipeline);
                    resulttmp(0 to lpm_pipeline - 1) := resulttmp(1 to lpm_pipeline);
                end if;
            end if;

            -- Send the pipelined result to output ports
            cout <= couttmp(0);
            overflow <= overflowtmp(0);
            result <= resulttmp(0)(lpm_width-1 downto 0);
        end if;
    end process;

end LPM_SYN;
-- END OF ARCHITECTURE


---START_ENTITY_HEADER---------------------------------------------------------
--
-- Entity Name     :  lpm_add_sub
--
-- Description     :  Parameterized adder/subtractor megafunction.
--
-- Limitation      :  n/a
--
-- Results Expected:  If performs as adder, the result will be dataa[]+datab[]+cin.
--                    If performs as subtractor, the result will be dataa[]-datab[]+cin-1.
--                    Also returns carry out bit and overflow status bit.
--
---END_ENTITY_HEADER-----------------------------------------------------------

-- LIBRARY USED----------------------------------------------------------------
library IEEE;
use IEEE.std_logic_1164.all;
use work.LPM_COMPONENTS.all;

-- ENTITY DECLARATION
entity LPM_ADD_SUB is
    generic (
        lpm_width          : natural;    -- MUST be greater than 0
        lpm_representation : string := "SIGNED";
        lpm_direction      : string := "UNUSED";
        lpm_pipeline       : natural := 0;
        lpm_type           : string := "LPM_ADD_SUB";
        lpm_hint           : string := "UNUSED"
    );
    
    port (
        dataa   : in std_logic_vector(lpm_width-1 downto 0);
        datab   : in std_logic_vector(lpm_width-1 downto 0);
        cin     : in std_logic := 'Z';
        add_sub : in std_logic := '1';
        clock   : in std_logic := '0';
        aclr    : in std_logic := '0';
        clken   : in std_logic := '1';
        result   : out std_logic_vector(lpm_width-1 downto 0);
        cout     : out std_logic;
        overflow : out std_logic
    );
end LPM_ADD_SUB;
-- END OF ENTITY

-- BEGINNING OF ARCHITECTURE
architecture LPM_SYN of LPM_ADD_SUB is

-- COMPONENT DECLARATION
    component LPM_ADD_SUB_SIGNED
            generic (
                lpm_width     : natural;    -- MUST be greater than 0
                lpm_direction : string := "UNUSED";
                lpm_pipeline  : natural := 0;
                lpm_type      : string := "LPM_ADD_SUB";
                lpm_hint      : string := "UNUSED"
            );
            port (
                dataa   : in std_logic_vector(lpm_width downto 1);
                datab   : in std_logic_vector(lpm_width downto 1);
                cin     : in std_logic := 'Z';
                add_sub : in std_logic := '1';
                clock   : in std_logic := '0';
                aclr    : in std_logic := '0';
                clken   : in std_logic := '1';
                result   : out std_logic_vector(lpm_width-1 downto 0);
                cout     : out std_logic;
                overflow : out std_logic
            );
    end component;

    component LPM_ADD_SUB_UNSIGNED
            generic (
                lpm_width     : natural;    -- MUST be greater than 0
                lpm_direction : string := "UNUSED";
                lpm_pipeline  : natural := 0;
                lpm_type      : string := "LPM_ADD_SUB";
                lpm_hint      : string := "UNUSED"
            );
            port (
                dataa   : in std_logic_vector(lpm_width-1 downto 0);
                datab   : in std_logic_vector(lpm_width-1 downto 0);
                cin     : in std_logic := 'Z';
                add_sub : in std_logic := '1';
                clock   : in std_logic := '0';
                aclr    : in std_logic := '0';
                clken   : in std_logic := '1';
                result   : out std_logic_vector(lpm_width-1 downto 0);
                cout     : out std_logic;
                overflow : out std_logic
            );
    end component;


begin

-- PROCESS DECLARATION

    -- basic error checking for invalid parameters
    MSG: process
    begin
    
        if ((lpm_representation /= "SIGNED") and
            (lpm_representation /= "UNSIGNED")) then
            ASSERT FALSE
            REPORT "Value of lpm_representation parameter must be SIGNED or UNSIGNED!"
            SEVERITY ERROR;
        end if;
        wait;
    end process MSG;

    L1: if (lpm_representation = "UNSIGNED") generate

        U:  LPM_ADD_SUB_UNSIGNED
            generic map (
                lpm_width => lpm_width,
                lpm_direction => lpm_direction,
                lpm_pipeline => lpm_pipeline,