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[/] [t400/] [tags/] [rel_0_1_beta/] [rtl/] [vhdl/] [t400_opc_table.vhd] - Blame information for rev 2

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1 2 arniml 
-------------------------------------------------------------------------------
2 
--
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-- The opcode decoder table.
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-- Maps the binary opcodes to the mnemonic type.
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--
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-- $Id: t400_opc_table.vhd,v 1.1.1.1 2006-05-06 01:56:44 arniml Exp $
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--
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-- Copyright (c) 2006 Arnim Laeuger (arniml@opencores.org)
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--
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-- All rights reserved
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--
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-- Redistribution and use in source and synthezised forms, with or without
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-- modification, are permitted provided that the following conditions are met:
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--
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-- Redistributions of source code must retain the above copyright notice,
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-- this list of conditions and the following disclaimer.
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--
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-- Redistributions in synthesized form must reproduce the above copyright
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-- notice, this list of conditions and the following disclaimer in the
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-- documentation and/or other materials provided with the distribution.
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--
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-- Neither the name of the author nor the names of other contributors may
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-- be used to endorse or promote products derived from this software without
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-- specific prior written permission.
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--
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-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
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-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- POSSIBILITY OF SUCH DAMAGE.
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--
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-- Please report bugs to the author, but before you do so, please
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-- make sure that this is not a derivative work and that
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-- you have the latest version of this file.
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--
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-- The latest version of this file can be found at:
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--      http://www.opencores.org/cvsweb.shtml/t400/
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--
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-------------------------------------------------------------------------------
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library ieee;
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use ieee.std_logic_1164.all;
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use work.t400_opt_pack.all;
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use work.t400_pack.all;
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entity t400_opc_table is
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  generic (
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    opt_type_g   : integer := t400_opt_type_420_c
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  );
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  port (
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    opcode_i     : in  byte_t;
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    mnemonic_o   : out mnemonic_t;
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    multi_byte_o : out boolean
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  );
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end t400_opc_table;
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architecture rtl of t400_opc_table is
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begin
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  -----------------------------------------------------------------------------
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  -- Process opc_decode
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  --
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  -- Purpose:
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  --   Decodes the opcode to the set of mnemonics.
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  --
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  opc_decode: process (opcode_i)
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    variable t41x_type_v : boolean;
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  begin
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    -- default assignment
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    mnemonic_o   <= MN_NOP;
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    multi_byte_o <= false;
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    -- determine type
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    t41x_type_v  := opt_type_g = t400_opt_type_410_c;
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    case opcode_i is
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      -- Mnemonic ASC----------------------------------------------------------
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      when "00110000" =>
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        mnemonic_o   <= MN_ASC;
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      -- Mnemonic ADD ---------------------------------------------------------
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      when "00110001" =>
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        mnemonic_o   <= MN_ADD;
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      -- Mnemonic ADT ---------------------------------------------------------
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      when "01001010" =>
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        if not t41x_type_v then
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          mnemonic_o <= MN_ADT;
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        end if;
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      -- Mnemonic AISC --------------------------------------------------------
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      when "01010001" | "01010010" | "01010011" |
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           "01010100" | "01010101" | "01010110" | "01010111" |
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           "01011000" | "01011001" | "01011010" | "01011011" |
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           "01011100" | "01011101" | "01011110" | "01011111" =>
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        mnemonic_o   <= MN_AISC;
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      -- Mnemonic CASC --------------------------------------------------------
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      when "00010000" =>
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        if not t41x_type_v then
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          mnemonic_o <= MN_CASC;
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        end if;
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      -- Mnemonic CLRA --------------------------------------------------------
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      when "00000000" =>
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        mnemonic_o   <= MN_CLRA;
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      -- Mnemonic COMP --------------------------------------------------------
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      when "01000000" =>
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        mnemonic_o   <= MN_COMP;
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      -- Mnemonic NOP ---------------------------------------------------------
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      when "01000100" =>
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        mnemonic_o   <= MN_NOP;
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      -- Mnemonic C -----------------------------------------------------------
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      when "00110010" |                                         -- RC
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           "00100010" =>                                        -- SC
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        mnemonic_o   <= MN_C;
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      -- Mnemonic XOR ---------------------------------------------------------
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      when "00000010" =>
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        mnemonic_o   <= MN_XOR;
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      -- Mnemonic JID ---------------------------------------------------------
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      when "11111111" =>
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        mnemonic_o   <= MN_JID;
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      -- Mnemonic JMP ---------------------------------------------------------
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      when "01100000" | "01100001" | "01100010" | "01100011" =>
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        mnemonic_o   <= MN_JMP;
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        multi_byte_o <= true;
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      -- Mnemonic JP_JSRP -----------------------------------------------------
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      when "10000000" | "10000001" | "10000010" | "10000011" |
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           "10000100" | "10000101" | "10000110" | "10000111" |
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           "10001000" | "10001001" | "10001010" | "10001011" |
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           "10001100" | "10001101" | "10001110" | "10001111" |
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           "10010000" | "10010001" | "10010010" | "10010011" |
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           "10010100" | "10010101" | "10010110" | "10010111" |
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           "10011000" | "10011001" | "10011010" | "10011011" |
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           "10011100" | "10011101" | "10011110" | "10011111" |
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           "10100000" | "10100001" | "10100010" | "10100011" |
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           "10100100" | "10100101" | "10100110" | "10100111" |
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           "10101000" | "10101001" | "10101010" | "10101011" |
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           "10101100" | "10101101" | "10101110" | "10101111" |
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           "10110000" | "10110001" | "10110010" | "10110011" |
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           "10110100" | "10110101" | "10110110" | "10110111" |
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           "10111000" | "10111001" | "10111010" | "10111011" |
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           "10111100" | "10111101" | "10111110" |
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           "11000000" | "11000001" | "11000010" | "11000011" |
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           "11000100" | "11000101" | "11000110" | "11000111" |
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           "11001000" | "11001001" | "11001010" | "11001011" |
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           "11001100" | "11001101" | "11001110" | "11001111" |
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           "11010000" | "11010001" | "11010010" | "11010011" |
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           "11010100" | "11010101" | "11010110" | "11010111" |
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           "11011000" | "11011001" | "11011010" | "11011011" |
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           "11011100" | "11011101" | "11011110" | "11011111" |
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           "11100000" | "11100001" | "11100010" | "11100011" |
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           "11100100" | "11100101" | "11100110" | "11100111" |
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           "11101000" | "11101001" | "11101010" | "11101011" |
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           "11101100" | "11101101" | "11101110" | "11101111" |
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           "11110000" | "11110001" | "11110010" | "11110011" |
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           "11110100" | "11110101" | "11110110" | "11110111" |
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           "11111000" | "11111001" | "11111010" | "11111011" |
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           "11111100" | "11111101" | "11111110" =>
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        mnemonic_o   <= MN_JP_JSRP;
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      -- Mnemonic JSR ---------------------------------------------------------
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      when "01101000" | "01101001" | "01101010" | "01101011" =>
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        mnemonic_o   <= MN_JSR;
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        multi_byte_o <= true;
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      -- Mnemonic RET ---------------------------------------------------------
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      when "01001000" =>
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        mnemonic_o   <= MN_RET;
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      -- Mnemonic RETSK -------------------------------------------------------
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      when "01001001" =>
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        mnemonic_o   <= MN_RETSK;
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      -- Mnemonic LD ----------------------------------------------------------
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      when "00000101" | "00010101" | "00100101" | "00110101" =>
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        mnemonic_o   <= MN_LD;
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      -- Mnemonic LDD_XAD -----------------------------------------------------
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      when "00100011" =>
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        mnemonic_o   <= MN_LDD_XAD;
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        multi_byte_o <= true;
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      -- Mnemonic LQID --------------------------------------------------------
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      when "10111111" =>
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        mnemonic_o   <= MN_LQID;
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      -- Mnemonic RMB ---------------------------------------------------------
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      when "01001100" | "01000101" | "01000010" | "01000011" =>
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        mnemonic_o   <= MN_RMB;
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      -- Mnemonic SMB ---------------------------------------------------------
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      when "01001101" | "01000111" | "01000110" | "01001011" =>
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        mnemonic_o   <= MN_SMB;
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      -- Mnemonic STII --------------------------------------------------------
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      when "01110000" | "01110001" | "01110010" | "01110011" |
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           "01110100" | "01110101" | "01110110" | "01110111" |
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           "01111000" | "01111001" | "01111010" | "01111011" |
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           "01111100" | "01111101" | "01111110" | "01111111" =>
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        mnemonic_o   <= MN_STII;
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      -- Mnemonic X -----------------------------------------------------------
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      when "00000110" | "00010110" | "00100110" | "00110110" =>
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        mnemonic_o   <= MN_X;
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      -- Mnemonic XDS ---------------------------------------------------------
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      when "00000111" | "00010111" | "00100111" | "00110111" =>
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        mnemonic_o   <= MN_XDS;
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      -- Mnemonic XIS ---------------------------------------------------------
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      when "00000100" | "00010100" | "00100100" | "00110100" =>
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        mnemonic_o   <= MN_XIS;
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      -- Mnemonic CAB ---------------------------------------------------------
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      when "01010000" =>
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        mnemonic_o   <= MN_CAB;
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      -- Mnemonic CBA ---------------------------------------------------------
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      when "01001110" =>
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        mnemonic_o   <= MN_CBA;
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      -- Mnemonic LBI ---------------------------------------------------------
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      when "00001000" | "00001001" | "00001010" | "00001011" |
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           "00001100" | "00001101" | "00001110" | "00001111" |
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           "00011000" | "00011001" | "00011010" | "00011011" |
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           "00011100" | "00011101" | "00011110" | "00011111" |
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           "00101000" | "00101001" | "00101010" | "00101011" |
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           "00101100" | "00101101" | "00101110" | "00101111" |
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           "00111000" | "00111001" | "00111010" | "00111011" |
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           "00111100" | "00111101" | "00111110" | "00111111" =>
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        mnemonic_o   <= MN_LBI;
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      -- Mnemonic XABR --------------------------------------------------------
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      when "00010010" =>
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        if not t41x_type_v then
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          mnemonic_o <= MN_XABR;
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        end if;
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      -- Mnemonic SKC ---------------------------------------------------------
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      when "00100000" =>
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        mnemonic_o   <= MN_SKC;
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      -- Mnemonic SKE ---------------------------------------------------------
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      when "00100001" =>
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        mnemonic_o   <= MN_SKE;
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      -- Mnemonic SKMBZ -------------------------------------------------------
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      when "00000001" | "00010001" | "00000011" | "00010011" =>
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        mnemonic_o   <= MN_SKMBZ;
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      -- Mnemonic SKT ---------------------------------------------------------
270 
      when "01000001" =>
271 
        if not t41x_type_v then
272 
          mnemonic_o <= MN_SKT;
273 
        end if;
274 
 
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      -- Mnemonic XAS ---------------------------------------------------------
276 
      when "01001111" =>
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        mnemonic_o   <= MN_XAS;
278 
 
279 
      -- Mnemonic EXT ---------------------------------------------------------
280 
      when "00110011" =>
281 
        mnemonic_o   <= MN_EXT;
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        multi_byte_o <= true;
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284 
 
285 
      when others =>
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        null;
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    end case;
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  end process opc_decode;
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  --
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  -----------------------------------------------------------------------------
291 
 
292 
end rtl;
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-------------------------------------------------------------------------------
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-- File History:
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--
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-- $Log: not supported by cvs2svn $
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