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--------------------------------------------------------------------------------
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--This file is part of fpga_gpib_controller.
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--
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-- Fpga_gpib_controller is free software: you can redistribute it and/or modify
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-- it under the terms of the GNU General Public License as published by
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-- the Free Software Foundation, either version 3 of the License, or
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-- (at your option) any later version.
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--
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-- Fpga_gpib_controller is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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-- You should have received a copy of the GNU General Public License
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-- along with Fpga_gpib_controller. If not, see <http://www.gnu.org/licenses/>.
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--------------------------------------------------------------------------------
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-- Entity: if_func_C
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-- Entity: if_func_C
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-- Date: 23:00:30 10/04/2011
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-- Date: 23:00:30 10/04/2011
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-- Author: apaluch
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-- Author: Andrzej Paluch
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--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use work.utilPkg.all;
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use work.utilPkg.all;
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entity commandEcoder is
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entity commandEcoder is
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port (
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port (
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-- data
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-- data
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data : in std_logic_vector (7 downto 0);
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data : in std_logic_vector (7 downto 0);
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-- status byte
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-- status byte
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status_byte : in std_logic_vector (7 downto 0);
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status_byte : in std_logic_vector (7 downto 0);
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-- PPR command data
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-- PPR command data
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ppBitValue : in std_logic;
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ppBitValue : in std_logic;
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ppLineNumber : in std_logic_vector (2 downto 0);
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ppLineNumber : in std_logic_vector (2 downto 0);
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-- func states
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-- func states
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APRS : in std_logic; -- affirmative poll response state
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APRS : in std_logic; -- affirmative poll response state
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CACS : in std_logic; -- controller active state (C)
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CACS : in std_logic; -- controller active state (C)
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-- commands
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-- commands
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ATN : in std_logic;
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ATN : in std_logic;
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END_OF : in std_logic;
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END_OF : in std_logic;
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IDY : in std_logic;
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IDY : in std_logic;
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DAC : in std_logic;
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DAC : in std_logic;
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RFD : in std_logic;
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RFD : in std_logic;
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DAV : in std_logic;
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DAV : in std_logic;
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IFC : in std_logic;
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IFC : in std_logic;
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REN : in std_logic;
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REN : in std_logic;
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SRQ : in std_logic; -- request for service
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SRQ : in std_logic; -- request for service
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DAB : in std_logic;
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DAB : in std_logic;
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EOS : in std_logic;
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EOS : in std_logic;
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RQS : in std_logic; -- part of STB
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RQS : in std_logic; -- part of STB
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STB : in std_logic;
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STB : in std_logic;
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TCT : in std_logic;
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TCT : in std_logic;
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PPR : in std_logic;
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PPR : in std_logic;
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-------------------------------------------
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-------------------------------------------
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-- data lines -----------------------------
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-- data lines -----------------------------
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-------------------------------------------
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-------------------------------------------
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DO : out std_logic_vector (7 downto 0);
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DO : out std_logic_vector (7 downto 0);
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output_valid : out std_logic;
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output_valid : out std_logic;
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-------------------------------------------
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-------------------------------------------
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-- control lines --------------------------
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-- control lines --------------------------
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-------------------------------------------
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-------------------------------------------
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-- DAV line
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-- DAV line
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DAV_line : out std_logic;
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DAV_line : out std_logic;
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-- NRFD line
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-- NRFD line
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NRFD_line : out std_logic;
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NRFD_line : out std_logic;
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-- NDAC line
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-- NDAC line
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NDAC_line : out std_logic;
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NDAC_line : out std_logic;
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-- ATN line
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-- ATN line
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ATN_line : out std_logic;
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ATN_line : out std_logic;
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-- EOI line
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-- EOI line
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EOI_line : out std_logic;
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EOI_line : out std_logic;
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-- SRQ line
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-- SRQ line
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SRQ_line : out std_logic;
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SRQ_line : out std_logic;
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-- IFC line
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-- IFC line
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IFC_line : out std_logic;
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IFC_line : out std_logic;
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-- REN line
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-- REN line
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REN_line : out std_logic
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REN_line : out std_logic
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);
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);
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end commandEcoder;
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end commandEcoder;
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architecture arch of commandEcoder is
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architecture arch of commandEcoder is
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signal modified_status_byte : std_logic_vector (7 downto 0);
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signal modified_status_byte : std_logic_vector (7 downto 0);
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signal PPR_resp : std_logic_vector (7 downto 0);
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signal PPR_resp : std_logic_vector (7 downto 0);
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begin
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begin
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ATN_line <= (ATN or IDY) and not END_OF;
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ATN_line <= (ATN or IDY) and not END_OF;
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EOI_line <= END_OF or IDY;
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EOI_line <= END_OF or IDY;
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DAV_line <= DAV;
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DAV_line <= DAV;
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NRFD_line <= not RFD;
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NRFD_line <= not RFD;
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NDAC_line <= not DAC;
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NDAC_line <= not DAC;
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SRQ_line <= SRQ;
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SRQ_line <= SRQ;
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IFC_line <= IFC;
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IFC_line <= IFC;
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REN_line <= REN;
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REN_line <= REN;
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output_valid <= STB or DAB or EOS or TCT or PPR or CACS;
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output_valid <= STB or DAB or EOS or TCT or PPR or CACS;
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DO <=
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DO <=
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data when DAB='1' or EOS='1' or CACS='1' else
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data when DAB='1' or EOS='1' or CACS='1' else
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"00001001" when TCT='1' else
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"00001001" when TCT='1' else
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PPR_resp when PPR='1' else
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PPR_resp when PPR='1' else
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modified_status_byte when STB='1' else
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modified_status_byte when STB='1' else
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"00000000";
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"00000000";
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-- modifies status byte
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-- modifies status byte
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process (status_byte, APRS) begin
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process (status_byte, APRS) begin
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modified_status_byte <= status_byte;
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modified_status_byte <= status_byte;
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modified_status_byte(6) <= APRS;
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modified_status_byte(6) <= APRS;
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end process;
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end process;
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-- sets PPR response
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-- sets PPR response
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process (ppBitValue, ppLineNumber) begin
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process (ppBitValue, ppLineNumber) begin
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PPR_resp <= "00000000";
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PPR_resp <= "00000000";
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case ppLineNumber is
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case ppLineNumber is
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------------------
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------------------
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when "000" =>
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when "000" =>
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PPR_resp(0) <= ppBitValue;
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PPR_resp(0) <= ppBitValue;
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------------------
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------------------
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when "001" =>
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when "001" =>
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PPR_resp(1) <= ppBitValue;
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PPR_resp(1) <= ppBitValue;
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------------------
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------------------
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when "010" =>
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when "010" =>
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PPR_resp(2) <= ppBitValue;
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PPR_resp(2) <= ppBitValue;
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------------------
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------------------
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when "011" =>
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when "011" =>
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PPR_resp(3) <= ppBitValue;
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PPR_resp(3) <= ppBitValue;
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------------------
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------------------
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when "100" =>
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when "100" =>
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PPR_resp(4) <= ppBitValue;
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PPR_resp(4) <= ppBitValue;
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------------------
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------------------
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when "101" =>
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when "101" =>
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PPR_resp(5) <= ppBitValue;
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PPR_resp(5) <= ppBitValue;
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------------------
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------------------
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when "110" =>
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when "110" =>
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PPR_resp(6) <= ppBitValue;
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PPR_resp(6) <= ppBitValue;
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------------------
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------------------
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when others =>
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when others =>
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PPR_resp(7) <= ppBitValue;
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PPR_resp(7) <= ppBitValue;
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end case;
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end case;
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end process;
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end process;
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end arch;
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end arch;
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