fftscale.vhd

RS的编码。最新的移动多媒体应用技术的源代码

-- ================================================================================
-- File: FFTscale.vhd
-- Version: v1.0
-- Author: olivercamel
-- Date: May.27.2006
-- Description:
-- After IFFT + FFT transform, datas are needed to shift left 3 bit. For more
-- additions, please read ALTERA FFT MegaCore User Guide Book.
-- ================================================================================

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

-- ================================================================================

entity FFTscale is
	port
	(
		-- clock input
		clk: in std_logic;
		-- 10 bits width input and output data ports
		inputReal: in std_logic_vector (9 downto 0);
		inputImag: in std_logic_vector (9 downto 0);
		outputReal: out std_logic_vector (9 downto 0);
		outputImag: out std_logic_vector (9 downto 0);
		-- simple ALTERA Atlantic interface ports
		sink_val: in std_logic;
		sink_sop: in std_logic;
		sink_eop: in std_logic;
		source_val: out std_logic;
		source_sop: out std_logic;
		source_eop: out std_logic
	);
end FFTscale;

-- ================================================================================

architecture structure of FFTscale is

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

begin

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

-- using falling edge
process(clk,sink_val,sink_sop,sink_eop,inputReal,inputImag)
begin
	if falling_edge(clk) then -- using falling edge
		if sink_val = '1' then
			outputReal <= std_logic_vector(shift_left(signed(inputReal),3));
			outputImag <= std_logic_vector(shift_left(signed(inputImag),3));
			source_val <= '1';
			source_sop <= sink_sop;
			source_eop <= sink_eop;
		else
			outputReal <= "0000000000";
			outputImag <= "0000000000";
			source_val <= '0';
			source_sop <= '0';
			source_eop <= '0';
		end if;
	end if;
end process;

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

end structure;

-- ================================================================================