comb_mltplr.vhd

来自「8051VHDL原代码」· VHDL 代码 · 共 45 行

--         Description: Multiplier with parameteriseable data width. Realised
--                      using combinational logic only.
--
--
--
--
-----------------------------------------------------------------------------------------
library IEEE; 
use IEEE.std_logic_1164.all; 
use IEEE.std_logic_arith.all; 
  
--------------------------------ENTITY DECLARATION----------------------------------------

entity comb_mltplr is

  generic (DWIDTH : integer := 8);

  port (mltplcnd_i : in  std_logic_vector(DWIDTH-1 downto 0);  -- Multiplicand
        mltplctr_i : in  std_logic_vector(DWIDTH-1 downto 0);  -- Multiplicator
        product_o  : out std_logic_vector((DWIDTH*2)-1 downto 0)); -- Product

end comb_mltplr;
----------------------------------------------------------------------------------------
architecture rtl of comb_mltplr is

begin  -- rtl

  -- purpose: Multiply the multiplicand with the multiplicator.
  -- type   : combinational
  -- inputs : dvdnd_i, dvsor_i
  -- outputs: product_o
  p_mltply: process (mltplctr_i, mltplcnd_i)

    variable v_product : unsigned(DWIDTH*2-1 downto 0);
    
  begin  -- process p_divide

    v_product := conv_unsigned(unsigned(mltplctr_i)
                               * unsigned(mltplcnd_i),DWIDTH*2);
    product_o <= std_logic_vector(v_product);

  end process p_mltply;

end rtl;
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