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T65_Pack.vhd
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T65_Pack.vhd
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-- ****
-- T65(b) core. In an effort to merge and maintain bug fixes ....
--
-- See list of changes in T65 top file (T65.vhd)...
--
-- ****
-- 65xx compatible microprocessor core
--
-- FPGAARCADE SVN: $Id: T65_Pack.vhd 1234 2015-02-28 20:14:50Z wolfgang.scherr $
--
-- Copyright (c) 2002...2015
-- Daniel Wallner (jesus <at> opencores <dot> org)
-- Mike Johnson (mikej <at> fpgaarcade <dot> com)
-- Wolfgang Scherr (WoS <at> pin4 <dot> at>
-- Morten Leikvoll ()
--
-- All rights reserved
--
-- Redistribution and use in source and synthezised forms, with or without
-- modification, are permitted provided that the following conditions are met:
--
-- Redistributions of source code must retain the above copyright notice,
-- this list of conditions and the following disclaimer.
--
-- Redistributions in synthesized form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution.
--
-- Neither the name of the author nor the names of other contributors may
-- be used to endorse or promote products derived from this software without
-- specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-- POSSIBILITY OF SUCH DAMAGE.
--
-- Please report bugs to the author(s), but before you do so, please
-- make sure that this is not a derivative work and that
-- you have the latest version of this file.
--
-- Limitations :
-- See in T65 top file (T65.vhd)...
library IEEE;
use IEEE.std_logic_1164.all;
package T65_Pack is
constant Flag_C : integer := 0;
constant Flag_Z : integer := 1;
constant Flag_I : integer := 2;
constant Flag_D : integer := 3;
constant Flag_B : integer := 4;
constant Flag_1 : integer := 5;
constant Flag_V : integer := 6;
constant Flag_N : integer := 7;
subtype T_Lcycle is std_logic_vector(2 downto 0);
constant Cycle_sync :T_Lcycle:="000";
constant Cycle_1 :T_Lcycle:="001";
constant Cycle_2 :T_Lcycle:="010";
constant Cycle_3 :T_Lcycle:="011";
constant Cycle_4 :T_Lcycle:="100";
constant Cycle_5 :T_Lcycle:="101";
constant Cycle_6 :T_Lcycle:="110";
constant Cycle_7 :T_Lcycle:="111";
function CycleNext(c:T_Lcycle) return T_Lcycle;
type T_Set_BusA_To is
(
Set_BusA_To_DI,
Set_BusA_To_ABC,
Set_BusA_To_X,
Set_BusA_To_Y,
Set_BusA_To_S,
Set_BusA_To_P,
Set_BusA_To_DA,
Set_BusA_To_DAO,
Set_BusA_To_DAX,
Set_BusA_To_AAX,
Set_BusA_To_DONTCARE
);
type T_Set_Addr_To is
(
Set_Addr_To_PBR,
Set_Addr_To_SP,
Set_Addr_To_ZPG,
Set_Addr_To_BA
);
type T_Write_Data is
(
Write_Data_DL,
Write_Data_ABC,
Write_Data_X,
Write_Data_Y,
Write_Data_S,
Write_Data_P,
Write_Data_PCL,
Write_Data_PCH,
Write_Data_AX,
Write_Data_AXB,
Write_Data_XB,
Write_Data_YB,
Write_Data_DONTCARE
);
type T_ALU_OP is
(
ALU_OP_OR, --"0000"
ALU_OP_AND, --"0001"
ALU_OP_EOR, --"0010"
ALU_OP_ADC, --"0011"
ALU_OP_EQ1, --"0100" EQ1 does not change N,Z flags, EQ2/3 does.
ALU_OP_EQ2, --"0101" Not sure yet whats the difference between EQ2&3. They seem to do the same ALU op
ALU_OP_CMP, --"0110"
ALU_OP_SBC, --"0111"
ALU_OP_ASL, --"1000"
ALU_OP_ROL, --"1001"
ALU_OP_LSR, --"1010"
ALU_OP_ROR, --"1011"
ALU_OP_BIT, --"1100"
-- ALU_OP_EQ3, --"1101"
ALU_OP_DEC, --"1110"
ALU_OP_INC, --"1111"
ALU_OP_ARR,
ALU_OP_ANC,
ALU_OP_SAX,
ALU_OP_XAA
-- ALU_OP_UNDEF--"----"--may be replaced with any?
);
type T_t65_dbg is record
I : std_logic_vector(7 downto 0); -- instruction
A : std_logic_vector(7 downto 0); -- A reg
X : std_logic_vector(7 downto 0); -- X reg
Y : std_logic_vector(7 downto 0); -- Y reg
S : std_logic_vector(7 downto 0); -- stack pointer
P : std_logic_vector(7 downto 0); -- processor flags
end record;
end;
package body T65_Pack is
function CycleNext(c:T_Lcycle) return T_Lcycle is
begin
case(c) is
when Cycle_sync=>
return Cycle_1;
when Cycle_1=>
return Cycle_2;
when Cycle_2=>
return Cycle_3;
when Cycle_3=>
return Cycle_4;
when Cycle_4=>
return Cycle_5;
when Cycle_5=>
return Cycle_6;
when Cycle_6=>
return Cycle_7;
when Cycle_7=>
return Cycle_sync;
when others=>
return Cycle_sync;
end case;
end CycleNext;
end T65_Pack;