translator_shift.vhd

Bcode_s_m_h.rar实现GPSB码接收、译码等工程

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_arith.all;
entity translator_shift is
  port(in_data:in std_logic_vector(3 downto 0);
       quit_out:out std_logic_vector(25 downto 0);
       clr,clk,j_in:in std_logic;
       j_out:out std_logic);
end translator_shift;
architecture a of translator_shift is
signal q_out: std_logic_vector(25 downto 0);
signal m:std_logic:='0';
signal w:std_logic:='0';
signal x:integer range 0 to 26;
signal p:std_logic_vector(1 downto 0);
begin
  process(clr,in_data)
  begin
   if(clr='1')then
    m<='0';
    w<='0';
   elsif(j_in='1')then
    m<='1'; 
    w<='1';
   else
    null;
   end if;
   if(in_data="0111")then
      p<="11";
    elsif(in_data="0011")then
      p<="10";  
    else
      p<="00";
    end if;
    end process; 
  process(clk,p)
  begin
  if(clk'event and clk='1')then
    if(w='0')then
    x<=0;
    elsif(p(1)='1')then 
    x<=x+1;
    q_out(25)<=p(0);
    for i in 25 downto 1 loop
    q_out(i-1)<=q_out(i);
    end loop;
    end if;
    end if;
    end process;
  process(clk,m,in_data)
  begin
  if(clk'event and clk='1')then
  if(m='0')then
    j_out<='0';
  elsif(x=26)then
    quit_out<=q_out(25 downto 0);
    j_out<='1';
  else
    null;
  end if;
  end if;
  end process;
 end a;