Subversion Repositories g729a_codec

-----------------------------------------------------------------

--                                                             --

-----------------------------------------------------------------

--                                                             --

-- Copyright (C) 2013 Stefano Tonello                          --

--                                                             --

-- 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 SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY         --

-- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   --

-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   --

-- FOR A PARTICULAR PURPOSE. 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.                                 --

--                                                             --

-----------------------------------------------------------------

---------------------------------------------------------------

-- adder with carry-in

---------------------------------------------------------------

library IEEE;

use IEEE.std_logic_1164.all;

use IEEE.numeric_std.all;

library WORK;

use WORK.G729A_ASIP_PKG.all;

use WORK.G729A_ASIP_BASIC_PKG.all;

use WORK.G729A_ASIP_ARITH_PKG.all;

entity G729A_ASIP_ADDER is

  generic(

    WIDTH : integer := 16

  );

  port(

    OPA_i : in signed(WIDTH-1 downto 0);

    OPB_i : in signed(WIDTH-1 downto 0);

    CI_i : in std_logic;

    SUM_o : out signed(WIDTH-1 downto 0)

  );

end G729A_ASIP_ADDER;

architecture ARC of G729A_ASIP_ADDER is

  signal TMP : signed(WIDTH downto 0);

begin

  -- this encoding forces inferring of an adder with carry-in,

  -- rather than two cascaded adders.

  TMP <= (OPA_i & '1') + (OPB_i & CI_i);

  SUM_o <= TMP(WIDTH downto 1);

end ARC;