jens
75f8ddd340
git-svn-id: http://moon:8086/svn/vhdl/trunk@171 cc03376c-175c-47c8-b038-4cd826a8556b
93 lines
2.7 KiB
VHDL
93 lines
2.7 KiB
VHDL
--------------------------------------------------------------------------------
|
|
-- Company:
|
|
-- Engineer:
|
|
--
|
|
-- Create Date: 12:16:14 10/02/05
|
|
-- Design Name:
|
|
-- Module Name: cordic_stage - Behavioral
|
|
-- Project Name:
|
|
-- Target Device:
|
|
-- Tool versions:
|
|
-- Description:
|
|
--
|
|
-- Dependencies:
|
|
--
|
|
-- Revision:
|
|
-- Revision 0.01 - File Created
|
|
-- Additional Comments:
|
|
--
|
|
--------------------------------------------------------------------------------
|
|
library IEEE;
|
|
use IEEE.STD_LOGIC_1164.ALL;
|
|
use IEEE.MATH_REAL.ALL;
|
|
USE ieee.numeric_std.ALL;
|
|
|
|
library ieee_proposed;
|
|
use ieee_proposed.math_utility_pkg.all;
|
|
use ieee_proposed.fixed_pkg.all;
|
|
|
|
library work;
|
|
use work.fixed_util_pkg.all;
|
|
use work.nco_pkg.all;
|
|
|
|
---- Uncomment the following library declaration if instantiating
|
|
---- any Xilinx primitives in this code.
|
|
--library UNISIM;
|
|
--use UNISIM.VComponents.all;
|
|
|
|
entity waverom_dual is
|
|
Generic
|
|
(
|
|
nbits_wave : integer := 12;
|
|
nbits_wave_frac : integer := 12;
|
|
nbits_rom_depth : integer := 12
|
|
);
|
|
Port
|
|
(
|
|
clk : in std_logic;
|
|
addr_i : in unsigned(nbits_rom_depth-1 downto 0);
|
|
addr_q : in unsigned(nbits_rom_depth-1 downto 0);
|
|
wave_i_out : out sfixed;
|
|
wave_q_out : out sfixed
|
|
);
|
|
end waverom_dual;
|
|
|
|
architecture Behavioral of waverom_dual is
|
|
|
|
-------------------------------------------------------------------------------
|
|
constant rom_depth : integer := 2**nbits_rom_depth;
|
|
type wave_mem_t is array (0 to rom_depth-1) of sfixed(sproto(nbits_wave, nbits_wave_frac)'high downto sproto(nbits_wave, nbits_wave_frac)'low);
|
|
|
|
constant sfixed_proto : sfixed(sproto(nbits_wave, nbits_wave_frac)'high downto sproto(nbits_wave, nbits_wave_frac)'low) := (others => '0');
|
|
|
|
-------------------------------------------------------------------------------
|
|
function to_wave_mem(wave_real : real_array_t; len : integer; proto : sfixed) return wave_mem_t is
|
|
variable res : wave_mem_t;
|
|
begin
|
|
for i in 0 to len-1 loop
|
|
res(i) := to_sfixed(wave_real(i), proto, fixed_saturate, fixed_round);
|
|
end loop;
|
|
|
|
return res;
|
|
end to_wave_mem;
|
|
|
|
-------------------------------------------------------------------------------
|
|
-- Create ROM
|
|
constant real_wave_tbl : real_array_t(0 to rom_depth-1) := cos_tbl(rom_depth, 0.25/real(rom_depth), 0.0);
|
|
constant wave_tbl : wave_mem_t := to_wave_mem(real_wave_tbl, rom_depth, sfixed_proto);
|
|
|
|
-------------------------------------------------------------------------------
|
|
begin
|
|
|
|
-------------------------------------------------------------------------------
|
|
proc_wave: process(clk)
|
|
begin
|
|
if rising_edge(clk) then
|
|
wave_i_out <= wave_tbl(to_integer(addr_i));
|
|
wave_q_out <= wave_tbl(to_integer(addr_q));
|
|
end if;
|
|
end process;
|
|
|
|
------------------------------------------------------------
|
|
end Behavioral;
|