Subversion Repositories gpib_controller

--------------------------------------------------------------------------------

--This file is part of fpga_gpib_controller.

--

-- Fpga_gpib_controller is free software: you can redistribute it and/or modify

-- it under the terms of the GNU General Public License as published by

-- the Free Software Foundation, either version 3 of the License, or

-- (at your option) any later version.

--

-- Fpga_gpib_controller 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 General Public License for more details.

-- You should have received a copy of the GNU General Public License

-- along with Fpga_gpib_controller.  If not, see <http://www.gnu.org/licenses/>.

--------------------------------------------------------------------------------

-- Entity: commandDecoder

-- Date:2011-10-07  

-- Author: Andrzej Paluch

--------------------------------------------------------------------------------

library ieee;

use ieee.std_logic_1164.all;

use work.utilPkg.all;

entity commandDecoder is

        port (

                -------------------------------------------

                -- data lines -----------------------------

                -------------------------------------------

                DI : in std_logic_vector (7 downto 0);

                -------------------------------------------

                -- control lines --------------------------

                -------------------------------------------

                -- DAV line

                DAV_line : in std_logic;

                -- NRFD line

                NRFD_line : in std_logic;

                -- NDAC line

                NDAC_line : in std_logic;

                -- ATN line

                ATN_line : in std_logic;

                -- EOI line

                EOI_line : in std_logic;

                -- SRQ line

                SRQ_line : in std_logic;

                -- IFC line

                IFC_line : in std_logic;

                -- REN line

                REN_line : in std_logic;

                -------------------------------------------

                -- internal settiongs ---------------------

                -------------------------------------------

                -- eos mark

                eosMark : in std_logic_vector (7 downto 0);

                -- eos used

                eosUsed : in std_logic;

                -- my listen address

                myListAddr : in std_logic_vector (4 downto 0);

                -- my talk address

                myTalkAddr : in std_logic_vector (4 downto 0);

                -- secondary address detected

                secAddrDetected : in std_logic;

                -------------------------------------------

                -- internal states ------------------------

                -------------------------------------------

                -- serial poll active state (T or TE)

                SPAS : in std_logic;

                -------------------------------------------

                -- single line commands -------------------

                -------------------------------------------

                -- attention

                ATN : out std_logic;

                -- data accepted

                DAC : out std_logic;

                -- data valid

                DAV : out std_logic;

                -- end

                END_c : out std_logic;

                -- identify

                IDY : out std_logic;

                -- interface clear

                IFC : out std_logic;

                -- remote enable

                REN : out std_logic;

                -- ready for data

                RFD : out std_logic;

                -- service request

                SRQ : out std_logic;

                -------------------------------------------

                -- multi line commands --------------------

                -------------------------------------------

                -- addressed command group

                ACG : out std_logic;

                -- data byte

                DAB : out std_logic;

                -- device clear

                DCL : out std_logic;

                -- end of string

                EOS : out std_logic;

                -- group execute trigger

                GET : out std_logic;

                -- go to local

                GTL : out std_logic;

                -- listen address group

                LAG : out std_logic;

                -- local lockout

                LLO : out std_logic;

                -- my listen address

                MLA : out std_logic;

                -- my talk address

                MTA : out std_logic;

                -- my secondary address

                MSA : out std_logic;

                -- null byte

                NUL : out std_logic;

                -- other secondary address

                OSA : out std_logic;

                -- other talk address

                OTA : out std_logic;

                -- primary command group

                PCG : out std_logic;

                -- parallel poll configure

                PPC : out std_logic;

                -- parallel poll enable

                PPE : out std_logic;

                -- parallel poll disable

                PPD : out std_logic;

                -- parallel poll response

                PPR : out std_logic;

                -- parallel poll unconfigure

                PPU : out std_logic;

                -- request service

                RQS : out std_logic;

                -- secondary command group

                SCG : out std_logic;

                -- selected device clear

                SDC : out std_logic;

                -- serial poll disable

                SPD : out std_logic;

                -- serial poll enable

                SPE : out std_logic;

                -- status byte

                STB : out std_logic;

                -- talk address group

                TAG : out std_logic;

                -- take control

                TCT : out std_logic;

                -- universal command group

                UCG : out std_logic;

                -- unlisten

                UNL : out std_logic;

                -- untalk

                UNT : out std_logic

        );

end commandDecoder;

architecture arch of commandDecoder is

        signal ATN_int, IDY_int : std_logic;

        signal SCG_int, MSA_int, TAG_int, MTA_int, ACG_int, UCG_int,

                LAG_int, STB_int : std_logic;

begin

        --------------------------------------

        -- single line

        --------------------------------------

        ATN_int <= ATN_line;

        ATN <= ATN_int;

        ----------------------

        DAC <= not NDAC_line;

        ----------------------

        DAV <= DAV_line;

        ----------------------

        END_c <= not ATN_line and EOI_line;

        ----------------------

        IDY_int <= ATN_line and EOI_line;

        IDY <= IDY_int;

        ----------------------

        IFC <= IFC_line;

        ----------------------

        REN <= REN_line;

        ----------------------

        RFD <= not NRFD_line;

        ----------------------

        SRQ <= SRQ_line;

        ---------------------------------------

        -- multiple line

        ---------------------------------------

        ACG_int <= ATN_int and to_stdl(DI(6 downto 4) = "000");

        ACG <= ACG_int;

        ---------------------------------------

        DAB <= not ATN_int and ((eosUsed and to_stdl(DI /= eosMark)) or not eosUsed);

        ---------------------------------------

        DCL <= ATN_int and to_stdl(DI(6 downto 0) = "0010100");

        ---------------------------------------

        EOS <= not ATN_int and eosUsed and to_stdl(DI = eosMark);

        ---------------------------------------

        GET <= ATN_int and to_stdl(DI(6 downto 0) = "0001000");

        ---------------------------------------

        GTL <= ATN_int and to_stdl(DI(6 downto 0) = "0000001");

        ---------------------------------------

        LAG_int <= ATN_int and to_stdl(DI(6 downto 5) = "01");

        LAG <= LAG_int;

        ---------------------------------------

        LLO <= ATN_int and to_stdl(DI(6 downto 0) = "0010001");

        ---------------------------------------

        MLA <= LAG_int and to_stdl(DI(4 downto 0) = myListAddr);

        ---------------------------------------

        MTA_int <= TAG_int and to_stdl(DI(4 downto 0) = myTalkAddr);

        MTA <= MTA_int;

        ---------------------------------------

        MSA_int <= SCG_int and secAddrDetected;

        MSA <= MSA_int;

        ---------------------------------------

        NUL <= ATN_int and to_stdl(DI = "00000000");

        ---------------------------------------

        OSA <= SCG_int and not MSA_int;

        ---------------------------------------

        OTA <= TAG_int and not MTA_int;

        ---------------------------------------

        PCG <= ACG_int or UCG_int or LAG_int or TAG_int;

        ---------------------------------------

        PPC <= ATN_int and to_stdl(DI(6 downto 0) = "0000101");

        ---------------------------------------

        PPE <= ATN_int and to_stdl(DI(6 downto 4) = "110");

        ---------------------------------------

        PPD <= ATN_int and to_stdl(DI(6 downto 4) = "111"); -- "-1110000" ?

        ---------------------------------------

        PPR <= ATN_int and IDY_int;

        ---------------------------------------

        PPU <= ATN_int and to_stdl(DI(6 downto 0) = "0010101");

        ---------------------------------------

        RQS <= STB_int and to_stdl(DI(6) = '1');

        ---------------------------------------

        SCG_int <= ATN_int and to_stdl(DI(6 downto 5) = "11");

        SCG <= SCG_int;

        ---------------------------------------

        SDC <= ATN_int and to_stdl(DI(6 downto 0) = "0000100");

        ---------------------------------------

        SPD <= ATN_int and to_stdl(DI(6 downto 0) = "0011001");

        ---------------------------------------

        SPE <= ATN_int and to_stdl(DI(6 downto 0) = "0011000");

        ---------------------------------------

        STB_int <= not ATN_int and SPAS;

        STB <= STB_int;

        ---------------------------------------

        TAG_int <= ATN_int and to_stdl(DI(6 downto 5) = "10");

        TAG <= TAG_int;

        ---------------------------------------

        TCT <= ATN_int and to_stdl(DI(6 downto 0) = "0001001");

        ---------------------------------------

        UCG_int <= ATN_int and to_stdl(DI(6 downto 4) = "001");

        UCG <= UCG_int;

        ---------------------------------------

        UNL <= ATN_int and to_stdl(DI(6 downto 0) = "0111111");

        ---------------------------------------

        UNT <= ATN_int and to_stdl(DI(6 downto 0) = "1011111");

end arch;