-- Phobos event selector steered through
-- the CAMAC dataway. Started 16.05.04.
-- Version 1.2 (ACEX) Copyright I.Tsurin,
-- FLNR JINR.

-- Modifications to the version 1.0:

-- 1. The ADC gate is extended from 6,35 us to 102 us;
-- 2. The BDP start delay is extended from 1,5 us to 6,35 us;
-- 3. The following signals were swapped:
--	      Stop_T1: (pin_204) <-> Target (pin_206);
--	      Stop_T2: (pin_202) <-> GTE_IN (pin_199).

-- Modifications to the version 1.1:
--
-- 1. Signals "Target", "Stop_T1", "Stop_T2" and
--    "GTE_IN" are back to their original layout
--    on the front-panel of the CAMAC #1 station;
-- 2. Mapping change of the IO signals for
--    the new NIM <-> TTL level adapter;
-- 3. The pile-up registers for the SPAC_1 and
--    PSAC_2 signals are set when more than one
--    pulse is registered during the TOF blocking
--    interval (KOI gate was the former pile-up
--    expectation time)
-- 4. The Pile-up bit is added for the target: the
--    first target pulse starts the TOF blocking
--    interval, during which this bit is set by any
--    other pulses. The register is cleared at the
--    end of the blocking interval interval, if no
--    physical events were registered, otherwise
--    its content is kept.
-- 5. The neutron gate output is multiplexed:
--        when NA(4)F(24) = 'N_Gate OFF', Gate = I_Gate;
--        when NA(4)F(26) = 'N_Gate ON',  Gate = N_Gate;
-- 6. The neutron counter A(6)F(0)/F(2) is added
--    to count pulses within a chosen gate. It
--    increments continuously for zero gate width. 
-- 7. The minimum width of the internally generated
--    ion gates (by the built-in delay line or by
--    the clock counter) is equal to the trigger
--    pulse width to let the first signal opening
--    this gate by the leading edge, latch itself
--    into KOI register by the trailing egde. The
--    externally-formed gate has no limitations.
-- 8. Fixing of gitter of the trailing edges of
--    the timing signals for the TOF-spectrometry:
--    the standard (original) pulse width results
--    in a correct start-stop sequence for the
--    KA-251M TDCs.

-- Module functions:
--------------------------------------------
-- NA(I)F(0) - read physics data;
-- NA(J)F(1) - survey board steering;
-- NA(I)F(2) - read and clear physics data;
-- NA(X)F(8) - test LAM ('X' - any);
-- NA(X)F(10) - test and clear LAM ('X' - any);
-- NA(J)F(11) - set steering defaults;
-- NA(I)F(16) - overwrite physics;
-- NA(J)F(17) - change steerings;
-- NA(K)F(24) - disable detector channels and LAM;
-- NA(K)F(26) - enable detector channels and LAM;
-- NA(K)F(27) - test detector channels;
--------------------------------------------

-- Group #1 (I) registers (physics data):
--------------------------------------------
-- KOI_REG (RW)	A(0)F(0)/F(2)/F(16)	- KOI register;
-- PIL_REG (RW)	A(1)F(0)/F(2)/F(16)	- Pile-up register;

-- EVT_CNT (R)	A(2)F(0)/F(2) - event counter;
-- SP1_CNT (R)	A(3)F(0)/F(2) - rate counter (left arm);
-- SP2_CNT (R)	A(4)F(0)/F(2) - rate counter (right arm);
-- TAR_CNT (R)	A(5)F(0)/F(2) - rate counter (target);
-- NEU_CNT (R)  A(6)F(0)/F(2) - flux counter (He3 detector)
--------------------------------------------

-- Group #2 (J) registers (board steerings):
--------------------------------------------
-- IGD_REG (RW) A(0)F(1)/F(17) - collecting time for ions;
-- NGD_REG (RW) A(1)F(1)/F(17) - collecting time for neutrons;
-- ADC_REG (RW) A(2)F(1)/F(17) - dE integrating time;

-- BLK_REG (RW) A(3)F(1)/F(17) - next TOF blocking time;
-- BDP_REG (RW) A(4)F(1)/F(17) - BDP start delay;
-- LAM_REG (RW) A(5)F(1)/F(17) - LAM assert time;

-- ION_REG (RW) A(6)F(1)/F(17) - multiplicity scheme;
-- SIN_REG (RW) A(7)F(1)/F(17) - scaling for single events;
--------------------------------------------

-- Control (K) registers:
--------------------------------------------
-- ENA_LAM (X) A(0)F(24)/F(26)			- L1 trigger OFF/ON;
-- ENA_CH1 (X) A(1)F(24)/F(26)/F(27)	- left  PSAC OFF/ON/Test;
-- ENA_CH2 (X) A(2)F(24)/F(26)/F(27)	- right PSAC OFF/ON/Test;
-- ENA_TAR (X) A(3)F(24)/F(26)/F(27)	- central PSAC OFF/ON/Test;
-- ENA_NEU (X) A(4)F(24)/F(26)/F(27)	- Neutron gate OFF/ON/Test;
--------------------------------------------

-- Bit assignment of the KOI register:
--------------------------------------------
-- Bit_0	Left  PSAC;
-- Bit_1	Right PSAC;
-- Bit_2	Target;
-- Bit_3	System bit (not cleared by SYS_RES);
--------------------------------------------

-- Bit assignment of the pile-up register:
--------------------------------------------
-- Bit_0	Left  PSAC;
-- Bit_1	Right PSAC;
-- Bit_2	Target;
--------------------------------------------

-- Bit assignment of the counters:
--------------------------------------------
-- Bit_0 ... Bit14 - counter's value (0 to 32767);
-- Bit_15          - overflow condition;
--------------------------------------------


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

--	OK. Here the entity starts...
--------------------------------------------
entity Selector is

port(

-- CAMAC signals
--------------------------------------------
	N_COM: in std_logic;
	B_COM: in std_logic;
	Z_COM: in std_logic;
	C_COM: in std_logic;
	I_COM: in std_logic;

	Strobe1: in std_logic;
	Strobe2: in std_logic;

	X_RES: out std_logic;
	Q_RES: out std_logic;
	L_RES: out std_logic;

	WRI_DAT: in std_logic_vector(23 downto 0);
	RDA_DAT: out std_logic_vector(23 downto 0);

	F_BUS: in std_logic_vector(4 downto 0);
	A_BUS: in std_logic_vector(3 downto 0);
--------------------------------------------

-- Detector signals
--------------------------------------------
	Target: in std_logic;

	Stop_T1: in std_logic;
	Stop_T2: in std_logic;

	Start_TDC1: out std_logic;
	Start_TDC2: out std_logic;
	
	Stop_TDC1: out std_logic;
	Stop_TDC2: out std_logic;

	Clear_TDC1: out std_logic;
	Clear_TDC2: out std_logic;

	Start_BDP1: out std_logic;
	Start_BDP2: out std_logic;

	Clear_BDP1: out std_logic;
	Clear_BDP2: out std_logic;
	
	Clear_TDC3: out std_logic;

	Start_DE: out std_logic;
	Clear_DE: out std_logic;

	N_Flux: in std_logic;
--------------------------------------------

-- Steering signals
--------------------------------------------
	GTE_IN: in std_logic;
	GTE_OUT: out std_logic;
	GTE_CTL: out std_logic;

	DEL_OUT: out std_logic;
	DEL_TAP: in std_logic_vector(9 downto 0);
--------------------------------------------	

-- Indicators
--------------------------------------------
	LAM_OUT: out std_logic;
	EVT_LED: out std_logic;
	BLK_GT1: out std_logic;
	BLK_GT2: out std_logic;
--------------------------------------------

-- Clock frequency
--------------------------------------------
	Clock: in std_logic
	);

	attribute pinnum: string;
	
	attribute pinnum of N_COM: signal is "18";
	attribute pinnum of B_COM: signal is "7";
	attribute pinnum of Z_COM: signal is "27";
	attribute pinnum of C_COM: signal is "16";
	attribute pinnum of I_COM: signal is "14";

	attribute pinnum of Strobe1: signal is "26";
	attribute pinnum of Strobe2: signal is "28";

	attribute pinnum of X_RES: signal is "12";
	attribute pinnum of Q_RES: signal is "29";
	attribute pinnum of L_RES: signal is "24";
	
	attribute pinnum of WRI_DAT: signal is "30,31,36,37,38,39,40,41,44,45,46,47,53,54,55,56,57,58,60,61,62,63,64,65";
	attribute pinnum of RDA_DAT: signal is "67,68,69,70,71,73,74,75,83,85,86,87,88,89,90,92,93,94,95,96,97,99,100,101";

	attribute pinnum of F_BUS: signal is "8,9,10,11,13";
	attribute pinnum of A_BUS: signal is "15,17,19,25";

	attribute pinnum of Target: signal is "141";

	attribute pinnum of Stop_T1: signal is "140";
	attribute pinnum of Stop_T2: signal is "139";

	attribute pinnum of Start_BDP1: signal is "204";
	attribute pinnum of Start_BDP2: signal is "203";

	attribute pinnum of Clear_BDP1: signal is "199";
	attribute pinnum of Clear_BDP2: signal is "198";

	attribute pinnum of LAM_OUT: signal is "206";
	attribute pinnum of EVT_LED: signal is "207";

	attribute pinnum of Start_TDC1: signal is "187";
	attribute pinnum of Start_TDC2: signal is "149";

	attribute pinnum of Stop_TDC1: signal is "148";
	attribute pinnum of Stop_TDC2: signal is "147";

	attribute pinnum of Start_DE: signal is "144";

	attribute pinnum of Clear_TDC1: signal is "191";
	attribute pinnum of Clear_TDC2: signal is "190";

	attribute pinnum of Clear_DE: signal is "142";
	attribute pinnum of Clear_TDC3: signal is "197";

	attribute pinnum of GTE_CTL: signal is "196";
	attribute pinnum of N_flux: signal is "195";

	attribute pinnum of BLK_GT1: signal is "202";
	attribute pinnum of BLK_GT2: signal is "200";

	attribute pinnum of GTE_IN: signal is "136";
	attribute pinnum of GTE_OUT: signal is "143";
	attribute pinnum of DEL_OUT: signal is "104";
	attribute pinnum of DEL_TAP: signal is "125,121,122,119,120,115,116,113,114,111";

	attribute pinnum of Clock: signal is "208";

end;

architecture behavior of Selector is

-- Start-up variables
--------------------------------------------
	signal INI_CNT: natural range 0 to 524287;
	signal DUM_RES: std_logic;
	signal PWR_ON: std_logic;
--------------------------------------------

-- CAMAC variables
--------------------------------------------
	signal COM_SET: std_logic;
	signal SEL_SET: std_logic;

	signal R29_KOI: std_logic;
	signal R29_PIL: std_logic;
	signal R29_EVT: std_logic;
	signal R29_SP1: std_logic;
	signal R29_SP2: std_logic;
	signal R29_TAR: std_logic;
	signal R29_NEU: std_logic;

	signal KOI_RG0: std_logic;
	signal KOI_RG1: std_logic;
	signal KOI_RG2: std_logic;
	signal KOI_RG3: std_logic;

	signal ARM: std_logic_vector(1 downto 0);

	signal PIL_RG0: std_logic;
	signal PIL_RG1: std_logic;
	signal PIL_RG2: std_logic;

	signal IGD_REG: natural range 0 to 127;		-- used #7 bit  -> 6.35 us;
	signal NGD_REG: natural range 0 to 2047;	-- used #11 bit -> 102 us;
	signal ADC_REG: natural range 0 to 2047;	-- used #11 bit -> 102 us;

	signal BLK_REG: natural range 0 to 127;		-- used #7 bit  -> 6.35 us;
	signal BDP_REG: natural range 0 to 127;		-- used #7 bit  -> 6.35 us;
	signal LAM_REG: natural range 0 to 2047;	-- used #11 bit -> 102 us;

	signal ION_REG: natural range 0 to 3;		-- #2 bit;
	signal SIN_REG: natural range 0 to 127;		-- #7 bit;

	signal ENA_LAM: std_logic;
	signal ENA_CH1: std_logic;
	signal ENA_CH2: std_logic;
	signal ENA_TAR: std_logic;
	signal ENA_NEU: std_logic;
--------------------------------------------

-- Physics variables
--------------------------------------------
-- TAR_STP - pulse synchronous to the leading  edge of the Target signal
-- TAR_KOI - pulse synchronous to the trailing edge of the Target signal
-- DM1_STP - pulse synchronous to the leading  edge of the PSAC_1 signal
-- DM1_KOI - pulse synchronous to the trailing edge of the PSAC_1 signal
-- DM2_STP - pulse synchronous to the leading  edge of the PSAC_2 signal
-- DM2_KOI - pulse synchronous to the trailing edge of the PSAC_2 signal

	signal TAR_STP: std_logic;
	signal TAR_KOI: std_logic;

	signal DM1_STP: std_logic;
	signal DM1_KOI: std_logic;
	signal DM1_OUT: std_logic;

	signal DM2_STP: std_logic;
	signal DM2_KOI: std_logic;
	signal DM2_OUT: std_logic;

	signal M1F_CLR: std_logic;
	signal M2F_CLR: std_logic;
	signal TAR_CLR: std_logic;

	signal HIS_KEP: std_logic;
	signal HIS_RES: std_logic;

	signal TF_CNT: natural range 0 to 255;
	signal M1F_CNT: natural range 0 to 255;
	signal M2F_CNT: natural range 0 to 255;

	signal BLK_LIM: natural range 0 to 255;

	signal CHAN_OR: std_logic;
	signal BACK_OR: std_logic;

	signal INT_CNT: natural range 0 to 255;
	signal INT_GTE: std_logic;
	signal INT_STB: std_logic;
	signal INT_CLR: std_logic;

	signal EXT_CNT: natural range 0 to 3;
	signal EXT_STB: std_logic;
	signal EXT_CLR: std_logic;

	signal DEL_CNT: natural range 0 to 3;
	signal DEL_STB: std_logic;
	signal DEL_CLR: std_logic;

	signal SHUT_GT: std_logic;
	signal ION_GTE: std_logic;
	signal NEU_GTE: std_logic;

	signal RDO_CNT: natural range 0 to 4095;
	signal RDO_LIM: natural range 0 to 4095;
	
	signal RDO_CYC: std_logic;

	signal ION_MUL: natural range 0 to 3;
	signal CNT_SIN: natural range 0 to 127;
	signal SIN_DEL: natural range 0 to 127;

	signal SIN_EVT: std_logic;
	signal BIN_EVT: std_logic;

	signal Event_OK: std_logic;
	signal L1_TRIG: std_logic;

	signal FST_CLR: std_logic;
	signal LAM_CLR: std_logic;
	signal SYS_RES: std_logic;
	signal RES_FAN: std_logic;
	signal DET_BSY: std_logic;

	signal RES_CNT: natural range 0 to 31;

	signal WRI_KOI: std_logic;
	signal WRI_PIL: std_logic;

	signal BDP_CN1: natural range 0 to 255;
	signal BDP_CN2: natural range 0 to 255;

	signal BDP_TM1: std_logic;
	signal BDP_TM2: std_logic;

	signal BDP_ST1: std_logic;
	signal BDP_ST2: std_logic;

	signal ADC_CNT: natural range 0 to 2047;
	signal ADC_GTE: std_logic;

	signal LED_CNT: natural range 0 to 131071;
	signal LAM_IND: std_logic;
--------------------------------------------

-- Spark counters
--------------------------------------------
	signal EVT_CNT: natural range 0 to 32767;
	signal SP1_CNT: natural range 0 to 32767;
	signal SP2_CNT: natural range 0 to 32767;
	signal TAR_CNT: natural range 0 to 32767;
	signal NEU_CNT: natural range 0 to 32767;

	signal EVT_OVF: std_logic;
	signal SP1_OVF: std_logic;
	signal SP2_OVF: std_logic;
	signal TAR_OVF: std_logic;
	signal NEU_OVF: std_logic;
--------------------------------------------

-- function declarations
--------------------------

-- Data type conversion:
-- binary#11 -> natural
--------------------------------------------
	function BIT11_inv_to_NUM(BIT_ARR: std_logic_vector(10 downto 0)) return natural is
		variable TEMP: natural range 0 to 2047;
	begin
			TEMP:=0;
		for I in BIT_ARR'range loop
			TEMP:= TEMP * 2;
			if (BIT_ARR(I) = '0') then
				TEMP:= TEMP + 1;
			else
				null;
			end if;
		end loop;
	return TEMP;
	end BIT11_inv_to_NUM;
--------------------------------------------

-- Data type conversion:
-- binary#7 -> natural
--------------------------------------------
	function BIT7_inv_to_NUM(BIT_ARR: std_logic_vector(6 downto 0)) return natural is
		variable TEMP: natural range 0 to 127;
	begin
			TEMP:=0;
		for I in BIT_ARR'range loop
			TEMP:= TEMP * 2;
			if (BIT_ARR(I) = '0') then
				TEMP:= TEMP + 1;
			else
				null;
			end if;
		end loop;
	return TEMP;
	end BIT7_inv_to_NUM;
--------------------------------------------

-- Data type conversion:
-- binary#2 -> natural
--------------------------------------------
	function BIT2_inv_to_NUM(BIT_ARR: std_logic_vector(1 downto 0)) return natural is
		variable TEMP: natural range 0 to 3;
	begin
			TEMP:=0;
		for I in BIT_ARR'range loop
			TEMP:= TEMP * 2;
			if (BIT_ARR(I) = '0') then
				TEMP:= TEMP + 1;
			else
				null;
			end if;
		end loop;
	return TEMP;
	end BIT2_inv_to_NUM;
--------------------------------------------

-- SUM_of_ONES_2 is used to count 
-- the number of PSACs triggered
--------------------------------------------
	function SUM_of_ONES_2(INP_DAT: std_logic_vector(1 downto 0)) return natural is
		variable TEMP: natural range 0 to 3;
	begin
		TEMP:= 0;
		for Index in INP_DAT'range loop
			if (INP_DAT(Index) = '1') then
				TEMP:= TEMP + 1;
			end if;
		end loop;
	return TEMP;
	end SUM_of_ONES_2;
--------------------------------------------


begin

-- Permanent statements
--------------------------------------------
	DUM_RES <= '0';
-------------------------
	ARM(0) <= KOI_RG0;
	ARM(1) <= KOI_RG1;
--------------------------------------------

-- Start-up reset
--------------------------------------------
	process(DUM_RES, Clock, PWR_ON)
	begin
		if (DUM_RES = '1') then
			INI_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (PWR_ON = '1') then
				INI_CNT <= INI_CNT + 1;
			else
				null;
			end if;
		end if;
	end process;
-------------------------
	process(DUM_RES, Clock, INI_CNT)
	begin
		if (DUM_RES = '1') then
			PWR_ON <= '1';
		elsif (Clock'event and Clock = '0') then
			if (INI_CNT = 524287) then
				PWR_ON <= '0';
			else
				PWR_ON <= '1';
			end if;
		end if;
	end process;
--------------------------------------------

-- Common CAMAC reset
-- (clear registers group #1)
-- (init  registers group #2)
--------------------------------------------
	process(PWR_ON, Z_COM, Strobe2)
	begin
		if (PWR_ON = '1' or Z_COM = '1') then
			COM_SET <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			COM_SET <= '1';
		end if;
	end process;
--------------------------------------------

-- Selective CAMAC reset
-- (clear registers group #1)
-- (init  registers group #2)
--------------------------------------------
	process(PWR_ON, C_COM, Strobe2)
	begin
		if (PWR_ON = '1' or C_COM = '1') then
			SEL_SET <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			SEL_SET <= '1';
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(0)F(2)S(2) or NA(0)F(9)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_KOI <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if ((F_BUS = "11101" or F_BUS = "10110") and A_BUS = "1111") then
				R29_KOI <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(1)F(2)S(2) or NA(1)F(9)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_PIL <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if ((F_BUS = "11101" or F_BUS = "10110") and A_BUS = "1110") then
				R29_PIL <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(2)F(2)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_EVT <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "11101" and A_BUS = "1101") then
				R29_EVT <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(3)F(2)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_SP1 <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "11101" and A_BUS = "1100") then
				R29_SP1 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(4)F(2)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_SP2 <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "11101" and A_BUS = "1011") then
				R29_SP2 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(5)F(2)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_TAR <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "11101" and A_BUS = "1010") then
				R29_TAR <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset group #1 by NA(6)F(2)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			R29_NEU <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "11101" and A_BUS = "1001") then
				R29_NEU <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset LAM by NA(X)F(10)S(2)
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, Strobe2, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			LAM_CLR <= '0';
		elsif (Strobe2'event and Strobe2 = '0') then
			if (F_BUS = "10101") then
				LAM_CLR <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Write group #2 registers (board steering)

-- Registers are  set to default values:
-- selected by a command NA(I)F(11)S(1);
-- all by a command ZS(2);
-- all by a command CS(2);
-- all after the power ON;

-- Registers are overwritten
-- by a command NA(I)F(17)S(1);
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, Strobe1,
			N_COM, F_BUS, A_BUS, WRI_DAT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1') then
			IGD_REG <= 11;
			NGD_REG <= 2000;
			ADC_REG <= 200;
			BLK_REG <= 100;
			BDP_REG <= 40;
			LAM_REG <= 400;
			ION_REG <= 3;
			SIN_REG <= 100;
		elsif (Strobe1'event and Strobe1 = '0') then
			if (N_COM = '0' and F_BUS = "10100") then
				if (A_BUS = "1111") then
					IGD_REG <= 11;
				elsif (A_BUS = "1110") then
					NGD_REG <= 2000;
				elsif (A_BUS = "1101") then
					ADC_REG <= 200;
				elsif (A_BUS = "1100") then
					BLK_REG <= 100;
				elsif (A_BUS = "1011") then
					BDP_REG <= 40;
				elsif (A_BUS = "1010") then
					LAM_REG <= 400;
				elsif (A_BUS = "1001") then
					ION_REG <= 3;
				elsif (A_BUS = "1000") then
					SIN_REG <= 100;
				else
					null;
				end if;
			elsif (N_COM = '0' and F_BUS = "01110") then
				if (A_BUS = "1111") then
					IGD_REG <= BIT7_inv_to_NUM(WRI_DAT(6 downto 0));
				elsif (A_BUS = "1110") then
					NGD_REG <= BIT11_inv_to_NUM(WRI_DAT(10 downto 0));
				elsif (A_BUS = "1101") then
					ADC_REG <= BIT11_inv_to_NUM(WRI_DAT(10 downto 0));
				elsif (A_BUS = "1100") then
					BLK_REG <= BIT7_inv_to_NUM(WRI_DAT(6 downto 0));
				elsif (A_BUS = "1011") then
					BDP_REG <= BIT7_inv_to_NUM(WRI_DAT(6 downto 0));
				elsif (A_BUS = "1010") then
					LAM_REG <= BIT11_inv_to_NUM(WRI_DAT(10 downto 0));
				elsif (A_BUS = "1001") then
					ION_REG <= BIT2_inv_to_NUM(WRI_DAT(1 downto 0));
				elsif (A_BUS = "1000") then
					SIN_REG <= BIT7_inv_to_NUM(WRI_DAT(6 downto 0));
				else
					null;
				end if;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Write group #3 registers (detector control)

-- Registers are  set to default values:
-- all by a command ZS(2);
-- all after the power ON;

-- Registers are overwritten
-- by commands NA(I)F(24)S(1)
-- and NA(I)F(26)S(1);
--------------------------------------------
	process(PWR_ON, COM_SET, Strobe1, N_COM, F_BUS, A_BUS)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			ENA_LAM <= '1';
			ENA_CH1 <= '1';
			ENA_CH2 <= '1';
			ENA_TAR <= '1';
			ENA_NEU <= '1';
		elsif (Strobe1'event and Strobe1 = '0') then
			if (N_COM = '0' and F_BUS = "00111") then
				if (A_BUS = "1111") then
					ENA_LAM <= '0';
				elsif (A_BUS = "1110") then
					ENA_CH1 <= '0';
				elsif (A_BUS = "1101") then
					ENA_CH2 <= '0';
				elsif (A_BUS = "1100") then
					ENA_TAR <= '0';
				elsif (A_BUS = "1011") then
					ENA_NEU <= '0';
				else
					null;
				end if;
			elsif (N_COM = '0' and F_BUS = "00101") then
				if (A_BUS = "1111") then
					ENA_LAM <= '1';
				elsif (A_BUS = "1110") then
					ENA_CH1 <= '1';
				elsif (A_BUS = "1101") then
					ENA_CH2 <= '1';
				elsif (A_BUS = "1100") then
					ENA_TAR <= '1';
				elsif (A_BUS = "1011") then
					ENA_NEU <= '1';
				else
					null;
				end if;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Read registers
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, F_BUS, A_BUS, KOI_RG0,
			KOI_RG1, KOI_RG2, KOI_RG3, PIL_RG0, PIL_RG1,
			PIL_RG2, EVT_OVF, EVT_CNT, SP1_OVF, SP1_CNT,
			SP2_OVF, SP2_CNT, TAR_OVF, TAR_CNT, NEU_OVF,
			NEU_CNT, IGD_REG, NGD_REG, ADC_REG, BLK_REG,
			BDP_REG, LAM_REG, ION_REG, SIN_REG)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			RDA_DAT <= (others => 'Z');

-- group #1 registers
--------------------------------------------
		elsif (F_BUS = "11111" or F_BUS = "11101") then
			if (A_BUS = "1111") then
				RDA_DAT(23 downto 4) <= (others => 'Z');
				RDA_DAT(3) <= not KOI_RG3;
				RDA_DAT(2) <= not KOI_RG2;
				RDA_DAT(1) <= not KOI_RG1;
				RDA_DAT(0) <= not KOI_RG0;
			elsif (A_BUS = "1110") then
				RDA_DAT(23 downto 3) <= (others => 'Z');
				RDA_DAT(2) <= not PIL_RG2;
				RDA_DAT(1) <= not PIL_RG1;
				RDA_DAT(0) <= not PIL_RG0;
			elsif (A_BUS = "1101") then
				RDA_DAT(23 downto 16) <= (others => 'Z');
				RDA_DAT(15) <= not EVT_OVF;
				RDA_DAT(14 downto 0) <= conv_std_logic_vector((32767 - EVT_CNT), 15);
			elsif (A_BUS = "1100") then
				RDA_DAT(23 downto 16) <= (others => 'Z');
				RDA_DAT(15) <= not SP1_OVF;
				RDA_DAT(14 downto 0) <= conv_std_logic_vector((32767 - SP1_CNT), 15);
			elsif (A_BUS = "1011") then
				RDA_DAT(23 downto 16) <= (others => 'Z');
				RDA_DAT(15) <= not SP2_OVF;
				RDA_DAT(14 downto 0) <= conv_std_logic_vector((32767 - SP2_CNT), 15);
			elsif (A_BUS = "1010") then
				RDA_DAT(23 downto 16) <= (others => 'Z');
				RDA_DAT(15) <= not TAR_OVF;
				RDA_DAT(14 downto 0) <= conv_std_logic_vector((32767 - TAR_CNT), 15);
			elsif (A_BUS = "1001") then
				RDA_DAT(23 downto 16) <= (others => 'Z');
				RDA_DAT(15) <= not NEU_OVF;
				RDA_DAT(14 downto 0) <= conv_std_logic_vector((32767 - NEU_CNT), 15);
			else
				RDA_DAT <= (others => 'Z');
			end if;

-- group #2 registers
--------------------------------------------
		elsif (F_BUS = "11110") then
			if (A_BUS = "1111") then
				RDA_DAT(23 downto 7) <= (others => 'Z');
				RDA_DAT(6 downto 0) <= conv_std_logic_vector((127 - IGD_REG), 7);
			elsif (A_BUS = "1110") then
				RDA_DAT(23 downto 11) <= (others => 'Z');
				RDA_DAT(10 downto 0) <= conv_std_logic_vector((2047 - NGD_REG), 11);
			elsif (A_BUS = "1101") then
				RDA_DAT(23 downto 11) <= (others => 'Z');
				RDA_DAT(10 downto 0) <= conv_std_logic_vector((2047 - ADC_REG), 11);
			elsif (A_BUS = "1100") then
				RDA_DAT(23 downto 7) <= (others => 'Z');
				RDA_DAT(6 downto 0) <= conv_std_logic_vector((127 - BLK_REG), 7);
			elsif (A_BUS = "1011") then
				RDA_DAT(23 downto 7) <= (others => 'Z');
				RDA_DAT(6 downto 0) <= conv_std_logic_vector((127 - BDP_REG), 7);
			elsif (A_BUS = "1010") then
				RDA_DAT(23 downto 11) <= (others => 'Z');
				RDA_DAT(10 downto 0) <= conv_std_logic_vector((2047 - LAM_REG), 11);
			elsif (A_BUS = "1001") then
				RDA_DAT(23 downto 2) <= (others => 'Z');
				RDA_DAT(1 downto 0) <= conv_std_logic_vector((3 - ION_REG), 2);
			elsif (A_BUS = "1000") then
				RDA_DAT(23 downto 7) <= (others => 'Z');
				RDA_DAT(6 downto 0) <= conv_std_logic_vector((127 - SIN_REG), 7);
			else
				RDA_DAT <= (others => 'Z');
			end if;
		else
			RDA_DAT <= (others => 'Z');
		end if;
	end process;
--------------------------------------------

-- Genarating X - command response

-- NA(I)F(0)  - read physics data;
-- NA(I)F(2)  - read and clear physics data;
-- NA(I)F(9)  - clear physics data;
-- NA(I)F(16) - overwrite physics;

-- NA(J)F(1)  - survey board steering;
-- NA(J)F(11) - set steering defaults;
-- NA(J)F(17) - change steerings;

-- NA(K)F(24) - disable detector channels and LAM;
-- NA(K)F(26) - enable detector channels and LAM;
-- NA(K)F(27) - test detector channels;

-- NA(X)F(8)  - test LAM ('X' - any);
-- NA(X)F(10) - test and clear LAM ('X' - any);
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, F_BUS, A_BUS)
	begin
		if (PWR_ON = '0' and Z_COM = '1' and N_COM = '0') then

-- overwrite or read group #1 registers
--------------------------------------------
			if (F_BUS = "11111" or F_BUS = "11101") then
				if (A_BUS = "1111") then
					X_RES <= '0';
				elsif (A_BUS = "1110") then
					X_RES <= '0';
				elsif (A_BUS = "1101") then
					X_RES <= '0';
				elsif (A_BUS = "1100") then
					X_RES <= '0';
				elsif (A_BUS = "1011") then
					X_RES <= '0';
				elsif (A_BUS = "1010") then
					X_RES <= '0';
				elsif (A_BUS = "1001") then
					X_RES <= '0';
				else
					X_RES <= 'Z';
				end if;
			elsif (F_BUS = "10110" or F_BUS = "01111") then
				if (A_BUS = "1111") then
					X_RES <= '0';
				elsif (A_BUS = "1110") then
					X_RES <= '0';
				else
					X_RES <= 'Z';
				end if;

-- overwrite or read group #2 registers
--------------------------------------------
			elsif (F_BUS = "11110" or F_BUS = "10100" or F_BUS = "01110") then
				if (A_BUS = "1111") then
					X_RES <= '0';
				elsif (A_BUS = "1110") then
					X_RES <= '0';
				elsif (A_BUS = "1101") then
					X_RES <= '0';
				elsif (A_BUS = "1100") then
					X_RES <= '0';
				elsif (A_BUS = "1011") then
					X_RES <= '0';
				elsif (A_BUS = "1010") then
					X_RES <= '0';
				elsif (A_BUS = "1001") then
					X_RES <= '0';
				elsif (A_BUS = "1000") then
					X_RES <= '0';
				else
					X_RES <= 'Z';
				end if;

-- disable or enable group #3 registers
--------------------------------------------
			elsif (F_BUS = "00111" or F_BUS = "00101") then
				if (A_BUS = "1111") then
					X_RES <= '0';
				elsif (A_BUS = "1110") then
					X_RES <= '0';
				elsif (A_BUS = "1101") then
					X_RES <= '0';
				elsif (A_BUS = "1100") then
					X_RES <= '0';
				elsif (A_BUS = "1011") then
					X_RES <= '0';
				else
					X_RES <= 'Z';
				end if;

-- test group #3 registers except LAM
--------------------------------------------
			elsif (F_BUS = "00100") then
				if (A_BUS = "1110") then
					X_RES <= '0';
				elsif (A_BUS = "1101") then
					X_RES <= '0';
				elsif (A_BUS = "1100") then
					X_RES <= '0';
				elsif (A_BUS = "1011") then
					X_RES <= '0';
				else
					X_RES <= 'Z';
				end if;
				
-- test or clear LAM
--------------------------------------------
			elsif (F_BUS = "10111" or F_BUS = "10101") then
				X_RES <= '0';
			else
				X_RES <= 'Z';
			end if;
		else
			X_RES <= 'Z';
		end if;
	end process;
--------------------------------------------

-- Genarating Q - status response
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, F_BUS, L1_TRIG, A_BUS, 
			ENA_CH1, ENA_CH2, ENA_TAR, ENA_NEU)
	begin
		if (PWR_ON = '0' and Z_COM = '1' and N_COM = '0') then
			if (F_BUS = "10111" or F_BUS = "10101") then
				Q_RES <= not L1_TRIG;
			elsif (F_BUS = "00100") then
				if (A_BUS = "1110") then
					Q_RES <= not ENA_CH1;
				elsif (A_BUS = "1101") then
					Q_RES <= not ENA_CH2;
				elsif (A_BUS = "1100") then
					Q_RES <= not ENA_TAR;
				elsif (A_BUS = "1011") then
					Q_RES <= not ENA_NEU;
				else
					Q_RES <= 'Z';
				end if;
			else
				Q_RES <= 'Z';
			end if;
		else
			Q_RES <= 'Z';
		end if;
	end process;
--------------------------------------------
--------------------------------------------

-- minimum channel blocking time = 200 ns
-- (blocking gate itself plus clear pulse) 
--------------------------------------------
	process(BLK_REG)
	begin
		case BLK_REG is
			when 0 to 2 =>
				BLK_LIM <= 3;
			when others =>
				BLK_LIM <= BLK_REG;
		end case;
	end process;
--------------------------------------------

-- Latching the leading edge of the target signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_TAR, TAR_CLR, Target, I_COM)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_TAR = '0' or TAR_CLR = '1') then
				TAR_STP <= '0';
		elsif (Target'event and Target = '1') then
			if (I_COM = '1') then
				TAR_STP <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Latching the trailing edge of the target signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_TAR, TAR_CLR, Target, I_COM)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_TAR = '0' or TAR_CLR = '1') then
				TAR_KOI <= '0';
		elsif (Target'event and Target = '0') then
			if (I_COM = '1') then
				TAR_KOI <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Extending the leading target pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, TAR_STP)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			TF_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (TAR_STP = '1') then
				TF_CNT <= TF_CNT + 1;
			else
				TF_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Synchronizing the leading target
-- pulse to the clock frequency
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, TF_CNT, BLK_LIM)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			TAR_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (TF_CNT = BLK_LIM) then
				TAR_CLR <= '1';
			else
				TAR_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- Latching the leading edge of the PSAC_1 signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_CH1, M1F_CLR, Stop_T1, I_COM, DET_BSY)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_CH1 = '0' or M1F_CLR = '1') then
				DM1_STP <= '0';
		elsif (Stop_T1'event and Stop_T1 = '1') then
			if (I_COM = '1' and DET_BSY = '0') then
				DM1_STP <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Latching the trailing edge of the PSAC_1 signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_CH1, M1F_CLR, Stop_T1, I_COM, DET_BSY)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_CH1 = '0' or M1F_CLR = '1') then
				DM1_KOI <= '0';
		elsif (Stop_T1'event and Stop_T1 = '0') then
			if (I_COM = '1' and DET_BSY = '0') then
				DM1_KOI <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Extending the leading PSAC_1 pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, DM1_STP)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			M1F_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (DM1_STP = '1') then
				M1F_CNT <= M1F_CNT + 1;
			else
				M1F_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Synchronizing the leading PSAC_1
-- pulse to the clock frequency
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, M1F_CNT, BLK_LIM)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			M1F_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (M1F_CNT = BLK_LIM) then
				M1F_CLR <= '1';
			else
				M1F_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- Latching the leading edge of the PSAC_2 signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_CH2, M2F_CLR, Stop_T2, I_COM, DET_BSY)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_CH2 = '0' or M2F_CLR = '1') then
				DM2_STP <= '0';
		elsif (Stop_T2'event and Stop_T2 = '1') then
			if (I_COM = '1' and DET_BSY = '0') then
				DM2_STP <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Latching the trailing edge of the PSAC_2 signal
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, ENA_CH2, M2F_CLR, Stop_T2, I_COM, DET_BSY)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or
			ENA_CH2 = '0' or M2F_CLR = '1') then
				DM2_KOI <= '0';
		elsif (Stop_T2'event and Stop_T2 = '0') then
			if (I_COM = '1' and DET_BSY = '0') then
				DM2_KOI <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Extending the leading PSAC_2 pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, DM2_STP)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			M2F_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (DM2_STP = '1') then
				M2F_CNT <= M2F_CNT + 1;
			else
				M2F_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Synchronizing the leading PSAC_2
-- pulse to the clock frequency
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, M2F_CNT, BLK_LIM)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			M2F_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (M2F_CNT = BLK_LIM) then
				M2F_CLR <= '1';
			else
				M2F_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- logical OR of all channels
-------------------------------------------
	CHAN_OR <= DM1_STP or DM2_STP;
	BACK_OR <= DM1_KOI or DM2_KOI;
-------------------------------------------

-- Forming the ion collection gate
--------------------------------------------
	process(PWR_ON, COM_SET, SHUT_GT, CHAN_OR)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SHUT_GT = '1') then
			ION_GTE <= '0';
		elsif (CHAN_OR'event and CHAN_OR = '1') then
			ION_GTE <= '1';
		end if;
	end process;
--------------------------------------------

-- Select a source to shut down the ion gate
-------------------------------------------
	process(IGD_REG, GTE_IN, DEL_TAP, INT_STB)
	begin
		case IGD_REG is
			when 0 =>
				SHUT_GT <= GTE_IN;
			when 1 =>
				SHUT_GT <= DEL_TAP(0);
			when 2 =>
				SHUT_GT <= DEL_TAP(1);
			when 3 =>
				SHUT_GT <= DEL_TAP(2);
			when 4 =>
				SHUT_GT <= DEL_TAP(3);
			when 5 =>
				SHUT_GT <= DEL_TAP(4);
			when 6 =>
				SHUT_GT <= DEL_TAP(5);
			when 7 =>
				SHUT_GT <= DEL_TAP(6);
			when 8 =>
				SHUT_GT <= DEL_TAP(7);
			when 9 =>
				SHUT_GT <= DEL_TAP(8);
			when 10 =>
				SHUT_GT <= DEL_TAP(9);
			when others =>
				SHUT_GT <= INT_STB;
		end case;
	end process;
-------------------------------------------

-- Start an external strobe to close the
-- ion gate
--------------------------------------------
	process(PWR_ON, COM_SET, EXT_CLR, CHAN_OR)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or EXT_CLR = '1') then
			EXT_STB <= '0';
		elsif (CHAN_OR'event and CHAN_OR = '1') then
			EXT_STB <= '1';
		end if;
	end process;
--------------------------------------------

-- External strobe counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, EXT_STB)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			EXT_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (EXT_STB = '1') then
				EXT_CNT <= EXT_CNT + 1;
			else
				EXT_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Finishing the external strobe
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, EXT_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			EXT_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (EXT_CNT = 1) then
				EXT_CLR <= '1';
			else
				EXT_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- Start a delay line strobe to close the
-- ion gate
--------------------------------------------
	process(PWR_ON, COM_SET, DEL_CLR, BACK_OR)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or DEL_CLR = '1') then
			DEL_STB <= '0';
		elsif (BACK_OR'event and BACK_OR = '1') then
			DEL_STB <= '1';
		end if;
	end process;
--------------------------------------------

-- Delay line strobe counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, DEL_STB)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			DEL_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (DEL_STB = '1') then
				DEL_CNT <= DEL_CNT + 1;
			else
				DEL_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Finishing the delay line strobe
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, DEL_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			DEL_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (DEL_CNT = 3) then
				DEL_CLR <= '1';
			else
				DEL_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- Start an internal gate
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, INT_CLR, BACK_OR)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or INT_CLR = '1') then
			INT_GTE <= '0';
		elsif (BACK_OR'event and BACK_OR = '1') then
			INT_GTE <= '1';
		end if;
	end process;
--------------------------------------------

-- Internal gate counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, INT_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			INT_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (INT_GTE = '1') then
				INT_CNT <= INT_CNT + 1;
			else
				INT_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Stop the internal gate
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, INT_CNT, IGD_REG)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			INT_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (INT_CNT = IGD_REG + 2) then
				INT_CLR <= '1';
			else
				INT_CLR <= '0';
			end if;
		end if;
	end process;
--------------------------------------------

-- Internal strobe to close the ion gate
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, INT_CNT, IGD_REG)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			INT_STB <= '0';
		elsif (Clock'event and Clock = '0') then
			if (INT_CNT = IGD_REG + 2) then
				INT_STB <= '0';
			elsif (INT_CNT = IGD_REG) then
				INT_STB <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Scaler for single events
--------------------------------------------
	ION_MUL <= SUM_of_ONES_2(ARM(1 downto 0));
--------------------------
	process(PWR_ON, COM_SET, SHUT_GT, SIN_REG, SIN_DEL, ION_MUL)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			CNT_SIN <= 0;
		elsif (SHUT_GT'event and SHUT_GT = '1') then
			if (ION_MUL = 1) then
				if (SIN_REG = 0 or SIN_REG = SIN_DEL) then
					CNT_SIN <= 0;
				else
					CNT_SIN <= CNT_SIN + 1;
				end if;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Begin the new scaler's cycle
--------------------------------------------
	process(PWR_ON, COM_SET, SHUT_GT, CNT_SIN)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			SIN_DEL <= 0;
		elsif (SHUT_GT'event and SHUT_GT = '0') then
			SIN_DEL <= CNT_SIN;
		end if;
	end process;
--------------------------------------------

-- Single event validation
--------------------------------------------
	process(ION_MUL, SIN_REG, CNT_SIN)
	begin
		if (ION_MUL = 1 and SIN_REG = CNT_SIN) then
			SIN_EVT <= '1';
		else
			SIN_EVT <= '0';
		end if;
	end process;
--------------------------------------------

-- Binary event validation
--------------------------------------------
	process(ION_MUL)
	begin
		if (ION_MUL = 2) then
			BIN_EVT <= '1';
		else
			BIN_EVT <= '0';
		end if;
	end process;
--------------------------------------------

-- Majority scheme
--------------------------------------------
	process(PWR_ON, COM_SET, SHUT_GT, ION_REG, SIN_EVT, BIN_EVT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			Event_OK <= '0';
		elsif (SHUT_GT'event and SHUT_GT = '0') then
			case ION_REG is
				when 1 =>
					Event_OK <= SIN_EVT;
				when 2 =>
					Event_OK <= BIN_EVT;
				when 3 =>
					Event_OK <= SIN_EVT or BIN_EVT;
				when others =>
					Event_OK <= '0';
			end case;
		end if;
	end process;
--------------------------------------------

-- Readout counter limits 
--------------------------------------------
	process(Event_OK, ENA_NEU, LAM_REG, NGD_REG)
	begin
		if (Event_OK = '1') then
			if (ENA_NEU = '1' and LAM_REG <= NGD_REG) then
				RDO_LIM <= NGD_REG + 2;
			else
				RDO_LIM <= LAM_REG + 1;
			end if;
		else
			RDO_LIM <= 3;
		end if;
	end process;
--------------------------------------------

-- Readout cycle
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, RDO_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			RDO_CYC <= '0';
		elsif (Clock'event and Clock = '0') then
			if (RDO_CNT = RDO_LIM + 1) then
				RDO_CYC <= '0';
			else
				RDO_CYC <= '1';
			end if;
		end if;
	end process;
--------------------------------------------

-- Readout counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SHUT_GT, RDO_CYC)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			RDO_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (SHUT_GT = '1') then
				RDO_CNT <= 0;
			elsif (RDO_CYC = '1') then
				RDO_CNT <= RDO_CNT + 1;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Event trigger (LAM)
--------------------------------------------
	process(PWR_ON, COM_SET, LAM_CLR, Clock, Event_OK, ENA_LAM, RDO_CNT, RDO_LIM)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or LAM_CLR = '1') then
			L1_TRIG <= '0';
		elsif (Clock'event and Clock = '0') then
			if (Event_OK = '1' and ENA_LAM = '1' and RDO_CNT = RDO_LIM) then
				L1_TRIG <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Fast clear pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, Event_OK, RDO_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			FST_CLR <= '0';
		elsif (Clock'event and Clock = '0') then
			if (Event_OK = '0') then
				if (RDO_CNT = 2) then
					FST_CLR <= '1';
				elsif (RDO_CNT = 3) then
					FST_CLR <= '0';
				else
					null;
				end if;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset DAQ and clear LAM
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, FST_CLR, LAM_CLR, RES_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			SYS_RES <= '0';
			RES_FAN <= '0';
		elsif (Clock'event and Clock = '1') then
			if (FST_CLR = '1' or LAM_CLR = '1') then
				SYS_RES <= '1';
				RES_FAN <= '1';
			elsif (RES_CNT = 31) then
				SYS_RES <= '0';
				RES_FAN <= '0';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset width counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			RES_CNT <= 0;
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1') then
				RES_CNT <= RES_CNT + 1;
			else
				RES_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Detector busy status:
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, SHUT_GT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1') then
			DET_BSY <= '0';
		elsif (SHUT_GT'event and SHUT_GT = '1') then
			DET_BSY <= '1';
		end if;
	end process;
--------------------------------------------

-- Group #1 registers write enable
--------------------------------------------
	process(PWR_ON, Z_COM, N_COM, F_BUS, Strobe1, A_BUS)
	begin
		if (PWR_ON = '1' or Z_COM = '0' or N_COM = '1') then
			WRI_KOI <= '0';
			WRI_PIL <= '0';
		elsif (F_BUS = "01111" and Strobe1 = '0') then
			if (A_BUS = "1111") then
				WRI_KOI <= '1';
				WRI_PIL <= '0';
			elsif (A_BUS = "1110") then
				WRI_KOI <= '0';
				WRI_PIL <= '1';
			else
				WRI_KOI <= '0';
				WRI_PIL <= '0';
			end if;
		else
			WRI_KOI <= '0';
			WRI_PIL <= '0';
		end if;
	end process;
--------------------------------------------

-- KOI register
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_KOI,
			WRI_KOI, WRI_DAT(0), DM1_KOI, ION_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1' or R29_KOI = '1') then
			KOI_RG0 <= '0';
		elsif (WRI_KOI = '1') then
			KOI_RG0 <= not WRI_DAT(0);
		elsif (DM1_KOI'event and DM1_KOI = '1') then
			if (ION_GTE = '1') then
				KOI_RG0 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_KOI,
			WRI_KOI, WRI_DAT(1), DM2_KOI, ION_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1' or R29_KOI = '1') then
			KOI_RG1 <= '0';
		elsif (WRI_KOI = '1') then
			KOI_RG1 <= not WRI_DAT(1);
		elsif (DM2_KOI'event and DM2_KOI = '1') then
			if (ION_GTE = '1') then
				KOI_RG1 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_KOI,
			WRI_KOI, WRI_DAT(2), TAR_KOI, ION_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1' or R29_KOI = '1') then
			KOI_RG2 <= '0';
		elsif (WRI_KOI = '1') then
			KOI_RG2 <= not WRI_DAT(2);
		elsif (TAR_KOI'event and TAR_KOI = '1') then
			if (ION_GTE = '1') then
				KOI_RG2 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_KOI,
			Strobe1, N_COM, F_BUS, A_BUS, WRI_DAT(3))
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or R29_KOI = '1') then
			KOI_RG3 <= '0';
		elsif (Strobe1'event and Strobe1 = '0') then
			if (N_COM = '0' and F_BUS = "01111" and A_BUS = "1111") then
				KOI_RG3 <= not WRI_DAT(3);
			else
				null;
			end if;
		else
			null;
		end if;
	end process;
--------------------------------------------

-- Pile-up register
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_PIL,
			WRI_PIL, WRI_DAT(0), Stop_T1, DM1_KOI)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1' or R29_PIL = '1') then
			PIL_RG0 <= '0';
		elsif (WRI_PIL = '1') then
			PIL_RG0 <= not WRI_DAT(0);
		elsif (Stop_T1'event and Stop_T1 = '1') then
			if (DM1_KOI = '1') then
				PIL_RG0 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_PIL,
			WRI_PIL, WRI_DAT(1), Stop_T2, DM2_KOI)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1' or R29_PIL = '1') then
			PIL_RG1 <= '0';
		elsif (WRI_PIL = '1') then
			PIL_RG1 <= not WRI_DAT(1);
		elsif (Stop_T2'event and Stop_T2 = '1') then
			if (DM2_KOI = '1') then
				PIL_RG1 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, R29_PIL, HIS_RES,
			WRI_PIL, WRI_DAT(2), Target, TAR_KOI)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			SYS_RES = '1' or R29_PIL = '1' or HIS_RES = '1') then
			PIL_RG2 <= '0';
		elsif (WRI_PIL = '1') then
			PIL_RG2 <= not WRI_DAT(2);
		elsif (Target'event and Target = '1') then
			if (TAR_KOI = '1') then
				PIL_RG2 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Reset the target pile-up when no event
-- in the PSAC_1 nor PSAC_2 occured during
-- the blocking time
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, SYS_RES, CHAN_OR)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or
			SEL_SET = '1' or SYS_RES = '1') then
			HIS_KEP <= '1';
		elsif (CHAN_OR'event and CHAN_OR = '1') then
			HIS_KEP <= '0';
		end if;
	end process;
--------------------------
	HIS_RES <= TAR_CLR and HIS_KEP;
--------------------------------------------

-- Counters for the discriminated pulses
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_EVT, ENA_LAM, L1_TRIG)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_EVT = '1' or ENA_LAM = '0') then
			EVT_CNT <= 0;
		elsif (L1_TRIG'event and L1_TRIG = '1') then
			EVT_CNT <= EVT_CNT + 1;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_SP1, ENA_CH1, Stop_T1)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_SP1 = '1' or ENA_CH1 = '0') then
			SP1_CNT <= 0;
		elsif (Stop_T1'event and Stop_T1 = '1') then
			SP1_CNT <= SP1_CNT + 1;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_SP2, ENA_CH2, Stop_T2)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_SP2 = '1' or ENA_CH2 = '0') then
			SP2_CNT <= 0;
		elsif (Stop_T2'event and Stop_T2 = '1') then
			SP2_CNT <= SP2_CNT + 1;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_TAR, ENA_TAR, Target)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or 
			R29_TAR = '1' or ENA_TAR = '0') then
			TAR_CNT <= 0;
		elsif (Target'event and Target = '1') then
			TAR_CNT <= TAR_CNT + 1;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_NEU, ENA_NEU, N_Flux, NGD_REG, NEU_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or 
			R29_NEU = '1' or ENA_NEU = '0') then
			NEU_CNT <= 0;
		elsif (N_Flux'event and N_Flux = '1') then
			if (NGD_REG = 0) then
				NEU_CNT <= NEU_CNT + 1;
			elsif (NEU_GTE = '1') then
				NEU_CNT <= NEU_CNT + 1;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- counter overflows
--------------------------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_EVT, ENA_LAM, L1_TRIG, EVT_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_EVT = '1' or ENA_LAM = '0') then
			EVT_OVF <= '0';
		elsif (L1_TRIG'event and L1_TRIG = '0') then
			if (EVT_CNT = 32767) then
				EVT_OVF <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_SP1, ENA_CH1, Stop_T1, SP1_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_SP1 = '1' or ENA_CH1 = '0') then
			SP1_OVF <= '0';
		elsif (Stop_T1'event and Stop_T1 = '0') then
			if (SP1_CNT = 32767) then
				SP1_OVF <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_SP2, ENA_CH2, Stop_T2, SP2_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or
			R29_SP2 = '1' or ENA_CH2 = '0') then
			SP2_OVF <= '0';
		elsif (Stop_T2'event and Stop_T2 = '0') then
			if (SP2_CNT = 32767) then
				SP2_OVF <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_TAR, ENA_TAR, Target, TAR_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or 
			R29_TAR = '1' or ENA_TAR = '0') then
			TAR_OVF <= '0';
		elsif (Target'event and Target = '0') then
			if (TAR_CNT = 32767) then
				TAR_OVF <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------
	process(PWR_ON, COM_SET, SEL_SET, R29_NEU, ENA_NEU, N_Flux, NEU_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SEL_SET = '1' or 
			R29_NEU = '1' or ENA_NEU = '0') then
			NEU_OVF <= '0';
		elsif (N_Flux'event and N_Flux = '0') then
			if (NEU_CNT = 32767) then
				NEU_OVF <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Shortening the TOF_1 pulse
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, DM1_KOI, DM1_STP)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or DM1_KOI = '1') then
			DM1_OUT <= '0';
		elsif (DM1_STP'event and DM1_STP = '1') then
			DM1_OUT <= '1';
		end if;
	end process;
--------------------------------------------

-- Shortening the TOF_2 pulse
--------------------------------------------
	process(PWR_ON, COM_SET, SYS_RES, DM2_KOI, DM2_STP)
	begin
		if (PWR_ON = '1' or COM_SET = '1' or SYS_RES = '1' or DM2_KOI = '1') then
			DM2_OUT <= '0';
		elsif (DM2_STP'event and DM2_STP = '1') then
			DM2_OUT <= '1';
		end if;
	end process;
--------------------------------------------

-- BDP_1 starting gate
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES, BDP_CN1, BDP_REG, M1F_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_TM1 <= '0';
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1' or BDP_CN1 = BDP_REG + 15) then
				BDP_TM1 <= '0';
			elsif (M1F_CNT = 1) then
				BDP_TM1 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- BDP_2 starting gate
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES, BDP_CN2, BDP_REG, M2F_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_TM2 <= '0';
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1' or BDP_CN2 = BDP_REG + 15) then
				BDP_TM2 <= '0';
			elsif (M2F_CNT = 1) then
				BDP_TM2 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- BDP_1 starting counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, BDP_TM1)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_CN1 <= 0;
		elsif (Clock'event and Clock = '1') then
			if (BDP_TM1 = '1') then
				BDP_CN1 <= BDP_CN1 + 1;
			else
				BDP_CN1 <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- BDP_2 starting counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, BDP_TM2)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_CN2 <= 0;
		elsif (Clock'event and Clock = '1') then
			if (BDP_TM2 = '1') then
				BDP_CN2 <= BDP_CN2 + 1;
			else
				BDP_CN2 <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- BDP_1 starting pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES, BDP_CN1, BDP_REG, M1F_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_ST1 <= '0';
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1' or BDP_CN1 = BDP_REG + 15) then
				BDP_ST1 <= '0';
			elsif (BDP_REG = 0) then
				if (M1F_CNT = 1) then
					BDP_ST1 <= '1';
				else
					null;
				end if;	
			elsif (BDP_CN1 = BDP_REG) then
				BDP_ST1 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- BDP_2 starting pulse
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES, BDP_CN2, BDP_REG, M2F_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			BDP_ST2 <= '0';
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1' or BDP_CN2 = BDP_REG + 15) then
				BDP_ST2 <= '0';
			elsif (BDP_REG = 0) then
				if (M2F_CNT = 1) then
					BDP_ST2 <= '1';
				else
					null;
				end if;
			elsif (BDP_CN2 = BDP_REG) then
				BDP_ST2 <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- ADC gate for the energy loss measurements
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, SYS_RES, ADC_CNT, ADC_REG)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			ADC_GTE <= '0';
		elsif (Clock'event and Clock = '0') then
			if (SYS_RES = '1' or ADC_CNT = ADC_REG) then
				ADC_GTE <= '0';
			elsif (EXT_CNT = 1) then
				ADC_GTE <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- ADC gate counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, ADC_GTE)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			ADC_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (ADC_GTE = '1') then
				ADC_CNT <= ADC_CNT + 1;
			else
				ADC_CNT <= 0;
			end if;
		end if;
	end process;
--------------------------------------------

-- Forming the gate for neutrons
-- (starts after the event decision)
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, RDO_CNT, NGD_REG, Event_OK, ENA_NEU)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			NEU_GTE <= '0';
		elsif (Clock'event and Clock = '0') then
			if (RDO_CNT = NGD_REG + 2) then
				NEU_GTE <= '0';
			elsif (Event_OK = '1' and ENA_NEU = '1' and RDO_CNT = 2) then
				NEU_GTE <= '1';
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- LAM indicator
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, LED_CNT)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			LAM_IND <= '0';
		elsif (Clock'event and Clock = '0') then
			if (LED_CNT = 131071) then
				LAM_IND <= '0';
			else
				LAM_IND <= '1';
			end if;
		end if;
	end process;
--------------------------------------------

-- LAM indicator counter
--------------------------------------------
	process(PWR_ON, COM_SET, Clock, L1_TRIG, LAM_IND)
	begin
		if (PWR_ON = '1' or COM_SET = '1') then
			LED_CNT <= 0;
		elsif (Clock'event and Clock = '1') then
			if (L1_TRIG = '1') then
				LED_CNT <= 0;
			elsif (LAM_IND = '1') then
				LED_CNT <= LED_CNT + 1;
			else
				null;
			end if;
		end if;
	end process;
--------------------------------------------

-- Pulse for the external gate delay
--------------------------------------------
	GTE_OUT <= not EXT_STB;						-- Socket 12
	DEL_OUT <= DEL_STB;
--------------------------------------------

-- starting TDCs
--------------------------------------------
	Start_TDC1 <= not DM1_OUT;					-- Socket 7
	Start_TDC2 <= not DM2_OUT;					-- Socket 8
--------------------------------------------

-- stopping TDCs
--------------------------------------------
	Stop_TDC1 <= not (ENA_CH1 and ENA_TAR and Target); -- Socket 9
	Stop_TDC2 <= not (ENA_CH2 and ENA_TAR and Target); -- Socket 10
--------------------------------------------

-- starting BDPs
--------------------------------------------
	Start_BDP1 <= not BDP_ST1;					-- Socket 5
	Start_BDP2 <= not BDP_ST2;					-- Socket 6
--------------------------------------------

-- starting ADC
--------------------------------------------
	Start_DE <= not ADC_GTE;					-- Socket 11
--------------------------------------------

-- System clear
--------------------------------------------
	Clear_DE <= not RES_FAN;					-- Socket 13

	Clear_TDC1 <= not ENA_CH1 and RES_FAN;
	Clear_TDC2 <= not ENA_CH2 and RES_FAN;

	Clear_TDC3 <= not RES_FAN;					-- Socket 14

	Clear_BDP1 <= not(ENA_CH1 and RES_FAN);
	Clear_BDP2 <= not(ENA_CH2 and RES_FAN);
--------------------------------------------

-- Gates
--------------------------------------------
	process(ENA_NEU, ION_GTE, NEU_GTE)
	begin
		if (ENA_NEU = '1') then
			GTE_CTL <= NEU_GTE;					-- Socket 15
		else
			GTE_CTL <= ION_GTE;					-- Socket 15
		end if;
	end process;
--------------------------------------------

-- L1 trigger request
--------------------------------------------
	L_RES <= not L1_TRIG;
--------------------------------------------

-- Indicators
--------------------------------------------
	LAM_OUT <= L1_TRIG;
	EVT_LED <= LAM_IND;
	BLK_GT1 <= DM1_STP;
	BLK_GT2 <= DM2_STP;
--------------------------------------------

end;