trigger_gen.vhd

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-- remove CMC slink status word until the first Header on L0 & L1 before each event
--
--  Ver 1.00
--
-- Dominique Gigi Jan 2011
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--   
--  
-- 
--  
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LIBRARY ieee;
--LIBRARY altera_mf;
--LIBRARY altera;


USE ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.std_logic_unsigned.all;
--LIBRARY lpm;
--USE lpm.lpm_components.all; 
--USE altera_mf.altera_mf_components.all;
--USE altera.altera_primitives_components.all;

entity trigger_gen is

port (
    reset       : IN std_logic;
    PCIe_clk        : IN std_logic;
    PCIe_func   : IN std_logic_vector(15 downto 0);
    PCIe_wen        : IN std_logic;
    PCIe_dti        : IN std_logic_vector(31 downto 0);
    PCIe_dto        : OUT std_logic_vector(31 downto 0);
    PCIe_cs     : IN std_logic;
    
    ttc_trigger : IN std_logic;
    
    evt_clk     : IN std_logic;
    ena_PCIe        : OUT std_logic;
    run_mode        : OUT std_logic;
    trig_nb     : OUT std_logic_vector(23 downto 0);
    trigger     : OUT std_logic;
    end_evt     : IN std_logic;
    Back_p      : IN std_logic
    );
end trigger_gen;

architecture behavioral of trigger_gen is

component resync
port (
    reset               : in std_logic;
    Free_clki       : in std_logic;
    clocki          : in std_logic;
    clocko          : in std_logic;
    input               : in std_logic;
    output          : out std_logic
    );
end component;
signal delay_end_evt            : std_logic_vector(3 downto 0);
signal pre_trig_loop            : std_logic;
signal pre_trig_TTC         : std_logic;
signal delay_pre_trg_TTC    : std_logic;
signal trigger_mux          : std_logic;
signal trig_sync                : std_logic;
signal trigger_cnt          : std_logic_vector(8 downto 0);
signal evt_cnt                  : std_logic_vector(63 downto 0);
signal check_trig               : std_logic;
signal evt_working          : std_logic;
signal pulse_trigger            : std_logic;
signal mem_evt_num          : std_logic_vector(23 downto 0);
signal pcie_ld                  : std_logic;
signal ld_evt_nm                : std_logic;
signal start                    : std_logic;
signal ena_PCI_trigger      : std_logic;
signal go_round             : std_logic;
signal reset_func               : std_logic;
signal PCI_trig             : std_logic;
 
--*********************************************************************
--**********************<< BEGIN  >>***********************************
--*********************************************************************
begin 

-- PCIe decoding function
process(reset,PCIe_clk)
begin
    if reset = '0' then
        go_round        <= '0';
        ena_PCI_trigger <= '0';
        start           <= '0';
 
        pre_trig_loop   <= '0';
        pre_trig_TTC    <= '0';
    elsif rising_edge(PCIe_clk) then
        -- set the loop trigger mode
        if      PCIe_cs = '1' and PCIe_func(0) = '1' and PCIe_dti(1) = '1' AND PCIe_wen = '1' then
            go_round <= '1';
        elsif   PCIe_cs = '1' and PCIe_func(0) = '1' and PCIe_dti(2) = '1' AND PCIe_wen = '1' then
            go_round <= '0';
        end if;
        -- select the trigger 
        if      PCIe_cs = '1' and PCIe_func(0) = '1' AND PCIe_wen = '1'  then
            ena_PCI_trigger <= PCIe_dti(3);
        end if;
        -- generate a PCI trigger
        PCI_trig <= '0';
        if      PCIe_cs = '1' and PCIe_func(0) = '1' and PCIe_dti(0) = '1' AND PCIe_wen = '1' then
            PCI_trig <= '1';
        end if;
        -- start to generate  triggers
        if      PCIe_cs = '1' and PCIe_func(0) = '1' AND PCIe_wen = '1' then
            start <= PCIe_dti(4);
        end if;

        pre_trig_loop <= '0';       -- pre trigger when loop mode
        if  PCIe_cs = '1' and PCIe_func(0) = '1'  and PCIe_dti(1) = '1' AND PCIe_wen = '1' then
            pre_trig_loop <= '1';
        end if;
        
        delay_pre_trg_TTC <= pre_trig_TTC;
        pre_trig_TTC <= '0';        -- pre trigger when TTC trigger used
        if  PCIe_cs = '1' and PCIe_func(0) = '1'  and PCIe_dti(4) = '1' AND PCIe_wen = '1' then
            pre_trig_TTC <= '1';
        end if; 
        
        pcie_ld <= '0';
        if  PCIe_cs = '1' and PCIe_func(1) = '1' AND PCIe_wen = '1' then
            pcie_ld <= '1';
            mem_evt_num <= PCIe_dti(23 downto 0);
        end if;
    end if;
end process;        


process(PCIe_clk)
begin
    if rising_edge(PCIe_clk) then
        PCIe_dto <= (others => '0');
        if      PCIe_func(0) = '1' then
            PCIe_dto(0) <= '0';
            PCIe_dto(1) <= go_round; 
            PCIe_dto(2) <= go_round;
            PCIe_dto(3) <= ena_PCI_trigger;
            PCIe_dto(4) <= start;
            PCIe_dto(5) <= '0';
            PCIe_dto(7 downto 6) <= (others => '0');
            PCIe_dto(8) <= evt_working;
            PCIe_dto(9) <= Back_p;
            PCIe_dto(31 downto 10) <= (others => '0');
        elsif   PCIe_func(1) = '1' then
            PCIe_dto(31 downto  0) <= evt_cnt(31 downto 0);
        elsif   PCIe_func(2) = '1' then
            PCIe_dto(31 downto  0) <= evt_cnt(63 downto 32);
                
        end if;
        
    end if;
end process;


-- if '1' the trigger and wc are from PCIe access (if '0'  trigger s and WC comes form FIFO memory_RND)
ena_PCIe <= ena_PCI_trigger;
-- specify that the event can be generated (all parametes should be set before going to this mode
run_mode <= start ;

trigger_mux <= '1' when  start = '1' and ((PCI_trig = '1' AND ena_PCI_trigger= '1')  or ( (ttc_trigger = '1' or delay_pre_trg_TTC = '1') AND ena_PCI_trigger= '0'))  else '0';

trg_gen:resync
port map(
    reset                => reset,
    Free_clki        => '1',        
    clocki           => PCIe_clk,
    input                => trigger_mux,
    clocko           => evt_clk,
    output           => trig_sync
    );

-- trigger counter
process(reset,start,evt_clk)
begin
    if reset = '0' or start = '0' then  
        trigger_cnt <= (others => '0');
    elsif rising_edge(evt_clk) then
        if trig_sync = '1' and end_evt = '0' then
            trigger_cnt <= trigger_cnt + "1";
        elsif  trig_sync = '0' and end_evt = '1' then
            trigger_cnt <= trigger_cnt - "1";
        end if;
    end if;
end process;

-- create a delay at the end of the event before starting the new one's
process(pre_trig_loop,evt_clk)
begin
if pre_trig_loop = '1' then
    delay_end_evt(0) <= '1';
elsif rising_edge(evt_clk) then
    delay_end_evt(3 downto 1) <= delay_end_evt(2 downto 0);
    delay_end_evt(0) <= end_evt;
end if;
end process;

process(reset,evt_clk)
begin
if reset = '0' then
    check_trig      <= '0';
    evt_working     <= '0';
    pulse_trigger   <= '0';
elsif rising_edge(evt_clk) then
    check_trig <= '0';
    if  start = '1' AND check_trig = '0' AND evt_working = '0' AND trigger_cnt /= "000000000" AND Back_p = '1' then
        check_trig <= '1';
    end if;
    
    pulse_trigger <= evt_working;
    if (delay_end_evt(3) = '1' AND go_round = '1' AND start = '1' ) OR (go_round = '0' AND check_trig = '1' ) then
        evt_working <= '1' ;
    elsif end_evt = '1' then
        evt_working <= '0' ;
    end if;
    
end if;
end process;
ld_evt_sync:resync
port map(
    reset            => reset,
    Free_clki        => '1',        
    clocki           => PCIe_clk,
    input            => pcie_ld,
    clocko           => evt_clk,
    output           => ld_evt_nm
    );

-- event counter managment
process(reset,evt_clk)
begin
if reset = '0' then
    evt_cnt <= (others => '0');
elsif rising_edge(evt_clk) then
    if ld_evt_nm = '1' then
        evt_cnt(63 downto 24) <= (others => '0');
        evt_cnt(23 downto 00) <= mem_evt_num;
    elsif end_evt = '1' then
        evt_cnt <= evt_cnt + "1";
    end if;
end if;
end process;

trigger     <= '1' when evt_working = '1' AND pulse_trigger = '0' else '0';
trig_nb     <= evt_cnt(23 downto 0);
 


end behavioral;