source: PROJECT_CORE_MPI/CORE_MPI/BRANCHES/v1.00/SetBit.vhd

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-- Company: 
-- Engineer: 
-- 
-- Create Date:    20:30:11 08/01/2013 
-- Design Name: 
-- Module Name:    SetBit - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
Library NocLib;
use NoCLib.CoreTypes.all;
--use work.packet_type.all;
-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating
-- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity SetBit is
    Port ( clk : in  STD_LOGIC;
           reset : in  STD_LOGIC;
                          BitMask : in std_logic_vector(Word-1 downto 0);
                          BitVal : in std_logic;
                          whole : in std_logic;                   
                          dma_wr_grant : in  STD_LOGIC;
                                dma_wr_request : out  STD_LOGIC;
                                dma_rd_grant : in  STD_LOGIC;
                                dma_rd_request : out  STD_LOGIC;
                                ram_rd : out std_logic;
                                ram_wr : out std_logic;
                                start : in std_logic;
                                done :  out std_logic;
                                ram_address : in std_logic_vector(ADRLEN-1 downto 0);--accès au stockage
                                Ram_data_in : out STD_LOGIC_VECTOR (Word-1 downto 0);
                                Ram_data_out : in STD_LOGIC_VECTOR (Word-1 downto 0));
end SetBit;

architecture Behavioral of SetBit is
signal n,State,Next_State:natural range 0 to 15 :=0;
signal dma_rd,dma_wr,rd_ok ,wr_ok:std_logic:='0';
begin
PSetBit_sync:process(clk,reset)

begin
if rising_edge(clk) then
if reset='1' then
        n<=0;
        State<=0;
else
  State<=Next_State;
end if;
end if;
end process;

PSetBit:process (State,Start,whole,BitMask,BitVal,Dma_rd_grant,Dma_wr_grant,ram_data_out)
  variable tempval : std_logic_vector(Word-1 downto 0);
  begin
    Next_State<=State;

    
if State >0  then     
                        
                dma_wr<='1';  --demander un accès exclusif au bus
                dma_rd<='1'; -- pour éviter une mauvaise mise à jour des données
        else
                dma_wr<='0';                                                                            
                dma_rd<='0';
        end if;
case State is
when 0 =>
  rd_ok<='0';
                Wr_ok<='0';
                done<='0';
        if  start='1' and whole='1' then
         Next_State<=5;
         wr_ok<='1';
         ram_data_in<=bitmask;
         elsif start='1' then
                Next_State<=State+1;
                end if;
                
when 1=>        if dma_rd_grant='1' then
                Next_State<=State+1;
                
                end if;
                rd_ok<='1';
                wr_ok<='0';
                done<='0';
        When 2|3=>
                if dma_rd_grant='1' then --cycle d'attente
                        Next_State<=State+1;
                else
                  Next_State<=1; --recommencer l'attente si perte de priorité
                end if;
                        rd_ok<='1';
                        wr_ok<='0';
                        done<='0';
        When 4 =>
                        if dma_rd_grant='1' and dma_wr_grant='1' then
                                Next_State<=6;
                                tempval:=Ram_data_out;
                                if bitval='1' then 
                                        tempval:= tempval or BitMask;   
                                else
                                        tempval:= tempval and not (BitMask);
                                end if;
                                if whole='1' then
                                  ram_data_in<=bitmask;
                                 else
                                  ram_data_in<=tempval;
                                end if;
                                rd_ok<='1';
                                wr_ok<='1';
                        else
                          Next_State<=State;
                          report "SetBit:Impossible d'avoir accès en R/W à la RAM";
                        end if;
        When 5 =>
          if dma_wr_grant='1' then
               if whole='1' then
                                    ram_data_in<=bitmask;
                                 else
                                    ram_data_in<=tempval;
                                end if;
                                Next_State<=6;
                end if;
                wr_ok<='1';
        When 6=>
                done<='1';
                if start='0' then
                Next_State<=0;
            wr_ok<='0'; 
                end if;
                rd_ok<='0';
                wr_ok<='1';
        When others =>
          Next_State<=0;
          rd_ok<='0';
                wr_ok<='0';
                done<='0';
end case;

end process PSetBit;
dma_rd_request <= dma_rd;
dma_wr_request <=dma_wr;
Ram_wr<=wr_ok;
Ram_rd<=rd_ok;
--Ram_data_out<=data_to_ram;
 
end Behavioral;