address_container.vhd

-------------------------------------
-- Author: Ryan Rivera, FNAL              
-- Created: Sep 11, 2015        
--  on Feb 3 -- BIG CHANGE, to not allow single byte address changing. Now a 32 bit reg in address space.
--  
-- This block takes decipher data on rising edge of capture_source_sig, if not 0 or 255    
--
-- This allows the 1 byte packet ("CAPTAN Ping") to change the ip addrs of the GEI remotely
--
-- NOTE: reseting returns the GEI to the default address as specified by user logic.
-------------------------------------   


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

            
use work.params_package.all;
                                                                    
entity address_container is
    port (                                                      
        clk : in std_logic;            
        capture : in std_logic;                                       
        data_in : in std_logic_vector(7 downto 0);          
                                             
        set_ctrl_dest_strobe : out std_logic;    
        set_data_dest_strobe : out std_logic;   
                                                                                    
        protocol_ping_strobe : out std_logic
        );
end;


architecture arch of address_container is      

    signal capture_old : std_logic;                                    

begin                         
        
    process(clk)
    begin
        
        if (rising_edge(clk)) then
            
            capture_old <= capture;           
            protocol_ping_strobe <= '0';      
            set_ctrl_dest_strobe <= '0';
            set_data_dest_strobe <= '0';
            
            if (capture_old = '0' and capture = '1') then   -- rising edge of source capture    
                if (data_in = x"00") then       -- 0s is used as "CAPTAN ping"  
                    protocol_ping_strobe <= '1';                                    
                elsif (data_in = x"01") then        -- 1 is used to set ctrl dest with the current source
                    set_ctrl_dest_strobe <= '1';                                    
                elsif (data_in = x"02") then        -- 2 is used to set data dest with the current source
                    set_data_dest_strobe <= '1';                                    
                --else (data_in = x"FF")            -- 1s is used as "CAPTAN no-op" 
                end if;    
            end if;   
                
        end if; 
        
    end process;
    
end arch;