Subversion Repositories gnextrapolator

--//// This file is part of the GNExtrapolator project                          ////
--//// http://opencores.org/project,gnextrapolator                                      ////
--////                                                                                                                          ////
--//// Description                                                                                                      ////
--//// Implementation of Algoritm for extrapolation functions       //// 
--////                                                                                                                          ////
--////                                                                                                                          ////
--//// To Do:                                                                                                           ////
--//// -                                                                                                                        ////
--////                                                                                                                          ////
--//// Author(s):                                                                                                       ////
--//// - Rodrigo Villegas, ruyvillegas@gmail.com, designer          ////
--//// - Pablo A. Salvadeo,     pas.@opencores, manager                                 ////
--////                                                                                                                          ////
--//////////////////////////////////////////////////////////////////////
--////                                                                                                                          ////
--//// Copyright (C) 2011 Authors and OPENCORES.ORG                             ////
--////                                                                                                                          ////
--//// This source file may be used and distributed without             ////
--//// restriction provided that this copyright statement is not        ////
--//// removed from the file and that any derivative work contains      ////
--//// the original copyright notice and the associated disclaimer.     ////
--////                                                                                                                          ////
--//// This source file is free software; you can redistribute it       ////
--//// and/or modify it under the terms of the GNU Lesser General       ////
--//// Public License as published by the Free Software Foundation;     ////
--//// either version 2.1 of the License, or (at your option) any       ////
--//// later version.                                                                                           ////
--////                                                                                                                          ////
--//// This source is distributed in the hope that it will be           ////
--//// useful, but WITHOUT ANY WARRANTY; without even the implied       ////
--//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR          ////
--//// PURPOSE. See the GNU Lesser General Public License for more      ////
--//// details.                                                                                                         ////
--////                                                                                                                          ////
--//// You should have received a copy of the GNU Lesser General        ////
--//// Public License along with this source; if not, download it       ////
--//// from http://www.opencores.org/lgpl.shtml                                         ////
--////                                                                                                                          ////
--//////////////////////////////////////////////////////////////////////

LIBRARY ieee; 
USE ieee.std_logic_1164.all; 
USE ieee.std_logic_signed.all; 
USE ieee.std_logic_arith.all;

entity gnextrapolator is
        port
        (
                rst_i   : in  std_logic;
                clk_i   : in  std_logic;
                distancia_i:    in std_logic_vector(7 downto 0);
                extrapolar_i:   in std_logic;
                indice_p_o:             out std_logic_vector(4 downto 0);       
                fxx_o:          out std_logic_vector(15 downto 0);
                fxx1_o:         out std_logic_vector(15 downto 0);
                fxx2_o:         out std_logic_vector(15 downto 0);
                fxx3_o:         out std_logic_vector(15 downto 0);
                fxx4_o:         out std_logic_vector(15 downto 0);
                resul_o:        out std_logic_vector(15 downto 0)
        );
end gnextrapolator;


architecture grenew of gnextrapolator is
-------------------------------------------------------------------------------------------------------
type columna is array(0 to 2) of std_logic_vector(15 downto 0);
signal sfx:             columna;        
signal indice:  integer range 0 to 31;
signal sram:    std_logic_vector(15 downto 0);

-------------------------------------------------------------------------------------------------------
        subtype word_t is std_logic_vector(15 downto 0);
        type memory_t is array(0 to 31) of word_t;      
        signal ram : memory_t;
        attribute romstyle :                    string;
        attribute romstyle of ram :     signal is "M512";
        attribute ram_init_file :               string;
        attribute ram_init_file of ram :signal is "gnextrapolator.mif";
-------------------------------------------------------------------------------------------------------
        
        
        
begin
process(rst_i,clk_i)
variable i:integer range 0 to 2 ;
variable resultado:std_logic_vector(15 downto 0);
variable fx: columna;
variable nabla1fx: columna;
variable nabla2fx: columna;
variable nabla3fx: columna;
variable nabla4fx: columna;
variable compensacion: columna;
variable cont:integer range 0 to 65535;

begin   
if (rst_i='1') then
        i:=0;
        cont:=0;
        fx(0):= (others=>'0');
        nabla1fx(0):= (others=>'0');
        nabla2fx(0):= (others=>'0');
        nabla3fx(0):= (others=>'0');
        nabla4fx(0):= (others=>'0');
        indice<=0;
elsif(rising_edge(clk_i)) then
        
        if(extrapolar_i = '0') then
        fx(i):= sram;
                                                                                --
                                                                                -- Se resiben los datos hasta que se ponga en alto el pin
        elsif(extrapolar_i = '1') then          -- 'extrapolar', con lo cual, se comienza a usar como valores   
        fx(i):=resultado;                                       --
        cont:= cont+1;                                          -- de la funcion los resultados calculados, y se deja de tomar datos 
        end if;                                                         -- de la entrada.
 
                                                                        
        nabla1fx(i):=(fx(i)-fx(i-1));                                                                           -- Se calculan los nablas y el resultado
        nabla2fx(i):=(nabla1fx(i)-nabla1fx(i-1));                                                       -- de sumar la ultima fila de vaores de 
        nabla3fx(i):=(nabla2fx(i)-nabla2fx(i-1));                                                       -- la tabla.    
        nabla4fx(i):=(nabla3fx(i)-nabla3fx(i-1));                                                       --
                                                                                                                                                --
        resultado:=fx(i)+nabla1fx(i)+nabla2fx(i)+nabla3fx(i)+nabla4fx(i);       --      
                                                        
        fxx_o   <=      fx(i);                                  --
        fxx1_o<=        nabla1fx(i);                    -- Se envian los datos a salidas para su observacion,
        fxx2_o<=        nabla2fx(i);                    -- el resultado se envia cada cierta cantidad de muestras
        fxx3_o<=        nabla3fx(i);                    -- definida por el usuario.
        fxx4_o<=        nabla4fx(i);                    --
        if(cont = distancia_i) then     --
        resul_o<=resultado;                     --
        cont:=0;                                        --
        end if;                                         --
        
        
        fx(0):=                 fx(i);                  -- se desplaza la fila hacia atras para poder calcular la siguiente
        nabla1fx(0):=   nabla1fx(i);    --
        nabla2fx(0):=   nabla2fx(i);    --
        nabla3fx(0):=   nabla3fx(i);    --
        nabla4fx(0):=   nabla4fx(i);    --

i:=1;
indice <= indice+1;
end if;

end process;
indice_p_o <= std_logic_vector(to_signed(indice));
--------------------------------------------------------------------------------------------------------------
process(clk_i)
        begin   
        if(falling_edge(clk_i)) then 
               sram <= ram(indice);
        end if;
end process;    
-----------------------------------------------------------------------------------------------------------------
end grenew;