detector.vhd

在扩频通信中

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


entity detector is
	generic(
		data_width:integer:=30;                                    --输入输出数据宽度
		thr:std_logic_vector(29 downto 0):="000000100111000100011110011000"    --门限值	
		);	                                     
	port(clk:in std_logic;
		reset:in std_logic;
		datain:in std_logic_vector(data_width-1 downto 0);
		relation:out std_logic
		);
end detector;

architecture behave of detector is
	type sh_reg is array(4 downto 0) of signed(data_width-1 downto 0);
	signal shift:sh_reg;
	signal thre_hold_val:signed(29 downto 0);
	signal sdatain:signed(data_width-1 downto 0);
	signal srelation:std_logic;
	signal ACQ_en:std_logic;
	
begin 
	sdatain<=signed(datain);
	thre_hold_val<=signed(thr);
	--选出最大值
	process(reset,clk)
	begin
		if(reset='1')then
			srelation<='0';	
		elsif(clk'event and clk='1')then
			shift<=shift(3 downto 0) & sdatain;
			if(shift(0)>thre_hold_val and shift(1)>thre_hold_val and shift(2)>thre_hold_val and shift(3)>thre_hold_val and shift(4)>thre_hold_val)then
				if(shift(2)>shift(0) and shift(2)>=shift(1) and shift(2)>=shift(3) and shift(2)>shift(4))then
					srelation<='1';	 
				else
					srelation<='0';
				end if;
			else
				srelation<='0';
			end if;
		end if;
	end process;   
	
	relation<=srelation;   
	
end behave;