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6502: Update T65 to latest version (same as AtomFpga) 

Change-Id: I580c5aff7bd4c7cd234f82c25519a081d20b239f
This commit is contained in:
David Banks 2019-11-03 12:14:21 +00:00
parent cd89e92a16
commit 5699d02d3d
4 changed files with 1459 additions and 1537 deletions
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298
src/T6502/T65.vhd
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@ -1,32 +1,65 @@
-- ****
-- T65(b) core. In an effort to merge and maintain bug fixes ....
--
-- Ver 313 WoS January 2015
-- Fixed issue that NMI has to be first if issued the same time as a BRK instruction is latched in
-- Now all Lorenz CPU tests on FPGAARCADE C64 core (sources used: SVN version 1021) are OK! :D :D :D
-- This is just a starting point to go for optimizations and detailed fixes (the Lorenz test can't find)
--
-- Ver 312 WoS January 2015
-- Undoc opcode timing fixes for $B3 (LAX iy) and $BB (LAS ay)
-- Added comments in MCode section to find handling of individual opcodes more easily
-- All "basic" Lorenz instruction test (individual functional checks, CPUTIMING check) work now with
-- actual FPGAARCADE C64 core (sources used: SVN version 1021).
--
-- Ver 305, 306, 307, 308, 309, 310, 311 WoS January 2015
-- Undoc opcode fixes (now all Lorenz test on instruction functionality working, except timing issues on $B3 and $BB):
-- SAX opcode
-- SHA opcode
-- SHX opcode
-- SHY opcode
-- SHS opcode
-- LAS opcode
-- alternate SBC opcode
-- fixed NOP with immediate param (caused Lorenz trap test to fail)
-- IRQ and NMI timing fixes (in conjuction with branches)
--
-- Ver 304 WoS December 2014
-- Undoc opcode fixes:
-- ARR opcode
-- ANE/XAA opcode
-- Corrected issue with NMI/IRQ prio (when asserted the same time)
--
-- Ver 303 ost(ML) July 2014
-- (Sorry for some scratchpad comments that may make little sense)
-- Mods and some 6502 undocumented instructions.
--
-- Not correct opcodes acc. to Lorenz tests (incomplete list):
-- Not correct opcodes acc. to Lorenz tests (incomplete list):
-- NOPN (nop)
-- NOPZX (nop + byte 172)
-- NOPAX (nop + word da ... da: byte 0)
-- ASOZ (byte $07 + byte 172)
--
-- Wolfgang April 2014
-- Ver 303 Bugfixes for NMI from foft
-- Ver 302 Bugfix for BRK command
-- Wolfgang January 2014
-- Ver 301 more merging
-- Ver 300 Bugfixes by ehenciak added, started tidyup *bust*
-- MikeJ March 2005
-- Latest version from www.fpgaarcade.com (original www.opencores.org)
-- Ver 303,302 WoS April 2014
-- Bugfixes for NMI from foft
-- Bugfix for BRK command (and its special flag)
--
-- Ver 300,301 WoS January 2014
-- More merging
-- Bugfixes by ehenciak added, started tidyup *bust*
--
-- MikeJ March 2005
-- Latest version from www.fpgaarcade.com (original www.opencores.org)
-- ****
--
-- 65xx compatible microprocessor core
--
-- Version : 0246
-- FPGAARCADE SVN: $Id: T65.vhd 1347 2015-05-27 20:07:34Z wolfgang.scherr $
--
-- Copyright (c) 2002 Daniel Wallner (jesus@opencores.org)
-- 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
--
@ -56,22 +89,37 @@
-- 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, but before you do so, please
-- 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.
--
-- The latest version of this file can be found at:
-- http://www.opencores.org/cvsweb.shtml/t65/
-- ----- IMPORTANT NOTES -----
--
-- Limitations :
-- Limitations:
-- 65C02 and 65C816 modes are incomplete (and definitely untested after all 6502 undoc fixes)
-- 65C02 supported : inc, dec, phx, plx, phy, ply
-- 65D02 missing : bra, ora, lda, cmp, sbc, tsb*2, trb*2, stz*2, bit*2, wai, stp, jmp, bbr*8, bbs*8
-- Some interface signals behave incorrect
-- NMI interrupt handling not nice, needs further rework (to cycle-based encoding).
--
-- 65C02 and 65C816 modes are incomplete
-- Undocumented instructions are not supported
-- Some interface signals behaves incorrect
-- Usage:
-- The enable signal allows clock gating / throttling without using the ready signal.
-- Set it to constant '1' when using the Clk input as the CPU clock directly.
--
-- File history :
-- TAKE CARE you route the DO signal back to the DI signal while R_W_n='0',
-- otherwise some undocumented opcodes won't work correctly.
-- EXAMPLE:
-- CPU : entity work.T65
-- port map (
-- R_W_n => cpu_rwn_s,
-- [....all other ports....]
-- DI => cpu_din_s,
-- DO => cpu_dout_s
-- );
-- cpu_din_s <= cpu_dout_s when cpu_rwn_s='0' else
-- [....other sources from peripherals and memories...]
--
-- 0246 : First release
-- ----- IMPORTANT NOTES -----
--
library IEEE;
@ -79,8 +127,6 @@ library IEEE;
use IEEE.numeric_std.all;
use work.T65_Pack.all;
-- ehenciak 2-23-2005 : Added the enable signal so that one doesn't have to use
-- the ready signal to limit the CPU.
entity T65 is
port(
Mode : in std_logic_vector(1 downto 0); -- "00" => 6502, "01" => 65C02, "10" => 65C816
@ -102,17 +148,18 @@ entity T65 is
VDA : out std_logic;
VPA : out std_logic;
A : out std_logic_vector(23 downto 0);
DI : in std_logic_vector(7 downto 0);--NOTE:Make sure DI equals DO when writing. This is important for DCP/DCM undoc instruction. TODO:convert to inout
DI : in std_logic_vector(7 downto 0);
DO : out std_logic_vector(7 downto 0);
-- 6502 registers (MSB) PC, SP, P, Y, X, A (LSB)
Regs : out std_logic_vector(63 downto 0)
Regs : out std_logic_vector(63 downto 0);
DEBUG : out T_t65_dbg
);
end T65;
architecture rtl of T65 is
-- Registers
signal ABC, X, Y, D : std_logic_vector(15 downto 0);
signal ABC, X, Y : std_logic_vector(15 downto 0);
signal P, AD, DL : std_logic_vector(7 downto 0) := x"00";
signal PwithB : std_logic_vector(7 downto 0);--ML:New way to push P with correct B state to stack
signal BAH : std_logic_vector(7 downto 0);
@ -149,6 +196,7 @@ architecture rtl of T65 is
signal BusA : std_logic_vector(7 downto 0);
signal BusA_r : std_logic_vector(7 downto 0);
signal BusB : std_logic_vector(7 downto 0);
signal BusB_r : std_logic_vector(7 downto 0);
signal ALU_Q : std_logic_vector(7 downto 0);
signal P_Out : std_logic_vector(7 downto 0);
@ -178,37 +226,39 @@ architecture rtl of T65 is
signal LDBAH : std_logic;
signal SaveP : std_logic;
signal Write : std_logic;
signal ALUmore : std_logic;
signal really_rdy : std_logic;
signal R_W_n_i : std_logic;
signal R_W_n_i_d : std_logic;
signal NMIActClear : std_logic; -- MWW hack
signal Res_n_i : std_logic;
signal Res_n_d : std_logic;
signal really_rdy : std_logic;
signal WRn_i : std_logic;
signal NMI_entered : std_logic;
begin
-- workaround for ready-handling
-- ehenciak : Drive R_W_n_i off chip.
R_W_n <= R_W_n_i;
-- ehenciak : gate Rdy with read/write to make an "OK, it's
-- really OK to stop the processor now if Rdy is
-- deasserted" signal
really_rdy <= Rdy or not(R_W_n_i);
----
-- gate Rdy with read/write to make an "OK, it's really OK to stop the processor
really_rdy <= Rdy or not(WRn_i);
Sync <= '1' when MCycle = "000" else '0';
EF <= EF_i;
MF <= MF_i;
XF <= XF_i;
R_W_n <= WRn_i;
ML_n <= '0' when IR(7 downto 6) /= "10" and IR(2 downto 1) = "11" and MCycle(2 downto 1) /= "00" else '1';
VP_n <= '0' when IRQCycle = '1' and (MCycle = "101" or MCycle = "110") else '1';
VDA <= '1' when Set_Addr_To_r /= Set_Addr_To_PBR else '0'; -- Incorrect !!!!!!!!!!!!
VPA <= '1' when Jump(1) = '0' else '0'; -- Incorrect !!!!!!!!!!!!
VDA <= '1' when Set_Addr_To_r /= Set_Addr_To_PBR else '0';
VPA <= '1' when Jump(1) = '0' else '0';
Regs <= std_logic_vector(PC) & std_logic_vector(S)& P & Y(7 downto 0) & X(7 downto 0) & ABC(7 downto 0);
-- debugging signals
DEBUG.I <= IR;
DEBUG.A <= ABC(7 downto 0);
DEBUG.X <= X(7 downto 0);
DEBUG.Y <= Y(7 downto 0);
DEBUG.S <= std_logic_vector(S(7 downto 0));
DEBUG.P <= P;
mcode : T65_MCode
Regs <= std_logic_vector(PC) & std_logic_vector(S)& P & Y(7 downto 0) & X(7 downto 0) & ABC(7 downto 0);
mcode : entity work.T65_MCode
port map(
--inputs
Mode => Mode_r,
@ -240,11 +290,10 @@ begin
LDBAL => LDBAL,
LDBAH => LDBAH,
SaveP => SaveP,
ALUmore => ALUmore,
Write => Write
);
alu : T65_ALU
alu : entity work.T65_ALU
port map(
Mode => Mode_r,
Op => ALU_Op_r,
@ -255,14 +304,25 @@ begin
Q => ALU_Q
);
-- the 65xx design requires at least two clock cycles before
-- starting its reset sequence (according to datasheet)
process (Res_n, Clk)
begin
if Res_n = '0' then
Res_n_i <= '0';
Res_n_d <= '0';
elsif Clk'event and Clk = '1' then
Res_n_i <= Res_n_d;
Res_n_d <= '1';
end if;
end process;
process (Res_n_i, Clk)
begin
if Res_n_i = '0' then
PC <= (others => '0'); -- Program Counter
IR <= "00000000";
S <= (others => '0'); -- Dummy !!!!!!!!!!!!!!!!!!!!!
D <= (others => '0');
S <= (others => '0'); -- Dummy
PBR <= (others => '0');
DBR <= (others => '0');
@ -271,7 +331,7 @@ begin
Write_Data_r <= Write_Data_DL;
Set_Addr_To_r <= Set_Addr_To_PBR;
R_W_n_i <= '1';
WRn_i <= '1';
EF_i <= '1';
MF_i <= '1';
XF_i <= '1';
@ -279,9 +339,8 @@ begin
elsif Clk'event and Clk = '1' then
if (Enable = '1') then
if (really_rdy = '1') then
R_W_n_i <= not Write or RstCycle;
WRn_i <= not Write or RstCycle;
D <= (others => '1'); -- Dummy
PBR <= (others => '1'); -- Dummy
DBR <= (others => '1'); -- Dummy
EF_i <= '0'; -- Dummy
@ -300,6 +359,10 @@ begin
else
IR <= DI;
end if;
if LDS = '1' then -- LAS won't work properly if not limited to machine cycle 0
S(7 downto 0) <= unsigned(ALU_Q);
end if;
end if;
ALU_Op_r <= ALU_Op;
@ -316,9 +379,6 @@ begin
if Dec_S = '1' and RstCycle = '0' then
S <= S - 1;
end if;
if LDS = '1' then
S(7 downto 0) <= unsigned(ALU_Q);
end if;
if IR = "00000000" and MCycle = "001" and IRQCycle = '0' and NMICycle = '0' then
PC <= PC + 1;
@ -329,10 +389,8 @@ begin
case Jump is
when "01" =>
PC <= PC + 1;
when "10" =>
PC <= unsigned(DI & DL);
when "11" =>
if PCAdder(8) = '1' then
if DL(7) = '0' then
@ -342,7 +400,6 @@ begin
end if;
end if;
PC(7 downto 0) <= PCAdder(7 downto 0);
when others => null;
end case;
end if;
@ -353,13 +410,13 @@ begin
PCAdder <= resize(PC(7 downto 0),9) + resize(unsigned(DL(7) & DL),9) when PCAdd = '1'
else "0" & PC(7 downto 0);
process (Res_n, Clk)
variable tmpP:std_logic_vector(7 downto 0);--ML:Lets try to handle loading P at mcycle=0 and set/clk flags at same cycle
process (Res_n_i, Clk)
variable tmpP:std_logic_vector(7 downto 0);--Lets try to handle loading P at mcycle=0 and set/clk flags at same cycle
begin
if Res_n = '0' then
P <= x"00"; -- ensure we have nothing set on reset (e.g. B flag!)
if Res_n_i = '0' then
P <= x"00"; -- ensure we have nothing set on reset
elsif Clk'event and Clk = '1' then
tmpP:=P;
tmpP:=P;
if (Enable = '1') then
if (really_rdy = '1') then
if MCycle = "000" then
@ -373,82 +430,59 @@ begin
Y(7 downto 0) <= ALU_Q;
end if;
if (LDA or LDX or LDY) = '1' then
-- P <= P_Out;-- Replaced with:
tmpP:=P_Out;
end if;
end if;
if SaveP = '1' then
-- P <= P_Out;-- Replaced with:
tmpP:=P_Out;
end if;
if LDP = '1' then
-- P <= ALU_Q;-- Replaced with: --ML:no need anymore: AND x"EF"; -- NEVER set B on RTI and PLP
tmpP:=ALU_Q;
end if;
if IR(4 downto 0) = "11000" then
case IR(7 downto 5) is
when "000" =>--0x18(clc)
-- P(Flag_C) <= '0';-- Replaced with:
tmpP(Flag_C) := '0';
when "001" =>--0x38(sec)
-- P(Flag_C) <= '1';
tmpP(Flag_C) := '1';
when "010" =>--0x58(cli)
-- P(Flag_I) <= '0';
tmpP(Flag_I) := '0';
when "011" =>--0x78(sei)
-- P(Flag_I) <= '1';
tmpP(Flag_I) := '1';
when "101" =>--0xb8(clv)
-- P(Flag_V) <= '0';
tmpP(Flag_V) := '0';
when "110" =>--0xd8(cld)
-- P(Flag_D) <= '0';
tmpP(Flag_D) := '0';
when "111" =>--0xf8(sed)
-- P(Flag_D) <= '1';
tmpP(Flag_D) := '1';
when others =>
end case;
end if;
--ML:Removed change of B flag, its constant '1' in P
--ML:The B flag appears to be locked to '1', but when pushed to stack, the SR data on the stack has the B flag cleared on interrupts, set on BRK instr.
--ML:The state of the B flag on warm reset apparently is unchanged (not confirmed, please do if you know)
--ML:The state of the B flag on cold reset is uncertain, but my guess would be set, unless it can be used to detect cold from warm reset.
--Since we cant (well, won't) simulate B=0 on cold reset, we just behave as if it was constant 1.
-- P(Flag_B) <= '1';
tmpP(Flag_B) := '1';
-- if IR = "00000000" and MCycle = "011" and RstCycle = '0' and NMICycle = '0' and IRQCycle = '0' then -- BRK
-- P(Flag_B) <= '1';
-- elsif IR = "00001000" then -- PHP
-- P(Flag_B) <= '1';
-- else
-- P(Flag_B) <= '0'; --> not the best way, but we keep B zero except for BRK and PHP opcodes
-- end if;
if IR = "00000000" and MCycle = "100" and RstCycle = '0' then --and (NMICycle = '1' or IRQCycle = '1') then
if IR = "00000000" and MCycle = "100" and RstCycle = '0' then
--This should happen after P has been pushed to stack
-- P(Flag_I) <= '1';
tmpP(Flag_I) := '1';
end if;
if SO_n_o = '1' and SO_n = '0' then
-- P(Flag_V) <= '1';
tmpP(Flag_V) := '1';
end if;
if RstCycle = '1' then
-- P(Flag_I) <= '0';
-- P(Flag_D) <= '0';
tmpP(Flag_I) := '1';
tmpP(Flag_D) := '0';
end if;
-- P(Flag_1) <= '1';
tmpP(Flag_1) := '1';
P<=tmpP;--new way
SO_n_o <= SO_n;
IRQ_n_o <= IRQ_n;
if IR(4 downto 0)/="10000" or Jump/="01" then -- delay interrupts during branches (checked with Lorenz test and real 6510), not best way yet, though - but works...
IRQ_n_o <= IRQ_n;
end if;
end if;
-- detect nmi even if not rdy
if IR(4 downto 0)/="10000" or Jump/="01" then -- delay interrupts during branches (checked with Lorenz test and real 6510) not best way yet, though - but works...
NMI_n_o <= NMI_n;
end if;
NMI_n_o <= NMI_n; -- MWW: detect nmi even if not rdy
end if;
end if;
end process;
@ -459,24 +493,26 @@ begin
--
---------------------------------------------------------------------------
process (Res_n, Clk)
process (Res_n_i, Clk)
begin
if Res_n = '0' then
if Res_n_i = '0' then
BusA_r <= (others => '0');
BusB <= (others => '0');
BusB_r <= (others => '0');
AD <= (others => '0');
BAL <= (others => '0');
BAH <= (others => '0');
DL <= (others => '0');
elsif Clk'event and Clk = '1' then
if (Enable = '1') then
NMI_entered <= '0';
if (really_rdy = '1') then
--if (Rdy = '1') then
BusA_r <= BusA;
if ALUmore='1' then
BusB <= ALU_Q;
else
BusB <= DI;
BusB <= DI;
-- not really nice, but no better way found yet !
if Set_Addr_To_r = Set_Addr_To_PBR or Set_Addr_To_r = Set_Addr_To_ZPG then
BusB_r <= std_logic_vector(unsigned(DI(7 downto 0)) + 1); -- required for SHA
end if;
case BAAdd is
@ -495,26 +531,25 @@ begin
when others =>
end case;
-- ehenciak : modified to use Y register as well (bugfix)
-- modified to use Y register as well
if ADAdd = '1' then
if (AddY = '1') then
AD <= std_logic_vector(unsigned(AD) + unsigned(Y(7 downto 0)));
AD <= std_logic_vector(unsigned(AD) + unsigned(Y(7 downto 0)));
else
AD <= std_logic_vector(unsigned(AD) + unsigned(X(7 downto 0)));
AD <= std_logic_vector(unsigned(AD) + unsigned(X(7 downto 0)));
end if;
end if;
NMIActClear <= '0';
if IR = "00000000" then
BAL <= (others => '1');
BAH <= (others => '1');
if RstCycle = '1' then
BAL(2 downto 0) <= "100";
elsif NMICycle = '1' then
BAL(2 downto 0) <= "100";
elsif NMICycle = '1' or (NMIAct = '1' and MCycle="100") or NMI_entered='1' then
BAL(2 downto 0) <= "010";
elsif NMIAct = '1' then -- MWW, force this to be changed by NMI, even if in midstream IRQ/brk
BAL(2 downto 0) <= "010";
NMIActClear <= '1';
if MCycle="100" then
NMI_entered <= '1';
end if;
else
BAL(2 downto 0) <= "110";
end if;
@ -523,7 +558,6 @@ begin
end if;
end if;
if LDDI = '1' then
DL <= DI;
end if;
@ -554,16 +588,20 @@ begin
Y(7 downto 0) when Set_BusA_To_Y,
std_logic_vector(S(7 downto 0)) when Set_BusA_To_S,
P when Set_BusA_To_P,
ABC(7 downto 0) and DI when Set_BusA_To_DA,
(ABC(7 downto 0) or x"ee") and DI when Set_BusA_To_DAO,--ee for OAL instruction. constant may be different on other platforms.TODO:Move to generics
(ABC(7 downto 0) or x"ee") and DI and X(7 downto 0) when Set_BusA_To_DAX,--XAA, ee for OAL instruction. constant may be different on other platforms.TODO:Move to generics
ABC(7 downto 0) and X(7 downto 0) when Set_BusA_To_AAX,--SAX, SHA
(others => '-') when Set_BusA_To_DONTCARE;--Can probably remove this
with Set_Addr_To_r select
A <=
"0000000000000001" & std_logic_vector(S(7 downto 0)) when Set_Addr_To_S,
DBR & "00000000" & AD when Set_Addr_To_AD,
"0000000000000001" & std_logic_vector(S(7 downto 0)) when Set_Addr_To_SP,
DBR & "00000000" & AD when Set_Addr_To_ZPG,
"00000000" & BAH & BAL(7 downto 0) when Set_Addr_To_BA,
PBR & std_logic_vector(PC(15 downto 8)) & std_logic_vector(PCAdder(7 downto 0)) when Set_Addr_To_PBR;
--ML:This is the P that gets pushed on stack with correct B flag. I'm not sure if NMI also clears B, but I guess it does.
-- This is the P that gets pushed on stack with correct B flag. I'm not sure if NMI also clears B, but I guess it does.
PwithB<=(P and x"ef") when (IRQCycle='1' or NMICycle='1') else P;
with Write_Data_r select
@ -576,6 +614,10 @@ begin
PwithB when Write_Data_P,
std_logic_vector(PC(7 downto 0)) when Write_Data_PCL,
std_logic_vector(PC(15 downto 8)) when Write_Data_PCH,
ABC(7 downto 0) and X(7 downto 0) when Write_Data_AX,
ABC(7 downto 0) and X(7 downto 0) and BusB_r(7 downto 0) when Write_Data_AXB, -- no better way found yet...
X(7 downto 0) and BusB_r(7 downto 0) when Write_Data_XB, -- no better way found yet...
Y(7 downto 0) and BusB_r(7 downto 0) when Write_Data_YB, -- no better way found yet...
(others=>'-') when Write_Data_DONTCARE;--Can probably remove this
@ -585,9 +627,9 @@ begin
--
-------------------------------------------------------------------------
process (Res_n, Clk)
process (Res_n_i, Clk)
begin
if Res_n = '0' then
if Res_n_i = '0' then
MCycle <= "001";
RstCycle <= '1';
IRQCycle <= '0';
@ -596,31 +638,29 @@ begin
elsif Clk'event and Clk = '1' then
if (Enable = '1') then
if (really_rdy = '1') then
if (NMIActClear = '1') then
NMIAct <= '0';
end if;
if MCycle = LCycle or Break = '1' then
MCycle <= "000";
RstCycle <= '0';
IRQCycle <= '0';
NMICycle <= '0';
if NMIAct = '1' then
if NMIAct = '1' and IR/=x"00" then -- delay NMI further if we just executed a BRK
NMICycle <= '1';
NMIAct <= '0'; -- reset NMI edge detector if we start processing the NMI
elsif IRQ_n_o = '0' and P(Flag_I) = '0' then
IRQCycle <= '1';
end if;
else
MCycle <= std_logic_vector(unsigned(MCycle) + 1);
end if;
if NMICycle = '1' then
NMIAct <= '0';
end if;
end if;
if NMI_n_o = '1' and NMI_n = '0' then -- MWW: detect nmi even if not rdy
end if;
--detect NMI even if not rdy
if NMI_n_o = '1' and (NMI_n = '0' and (IR(4 downto 0)/="10000" or Jump/="01")) then -- branches have influence on NMI start (not best way yet, though - but works...)
NMIAct <= '1';
end if;
-- we entered NMI during BRK instruction
if NMI_entered='1' then
NMIAct <= '0';
end if;
end if;
end if;
end process;

201
src/T6502/T65_ALU.vhd
View File

@ -1,20 +1,18 @@
-- ****
-- T65(b) core. In an effort to merge and maintain bug fixes ....
--
--
-- Ver 303 ost(ML) July 2014
-- ALU opcodes to vhdl types
-- Ver 300 Bugfixes by ehenciak added
-- MikeJ March 2005
-- Latest version from www.fpgaarcade.com (original www.opencores.org)
-- See list of changes in T65 top file (T65.vhd)...
--
-- ****
-- 65xx compatible microprocessor core
--
-- 6502 compatible microprocessor core
-- FPGAARCADE SVN: $Id: T65_ALU.vhd 1234 2015-02-28 20:14:50Z wolfgang.scherr $
--
-- Version : 0245
--
-- Copyright (c) 2002 Daniel Wallner (jesus@opencores.org)
-- 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
--
@ -44,19 +42,12 @@
-- 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, but before you do so, please
-- 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.
--
-- The latest version of this file can be found at:
-- http://www.opencores.org/cvsweb.shtml/t65/
--
-- Limitations :
--
-- File history :
--
-- 0245 : First version
--
-- See in T65 top file (T65.vhd)...
library IEEE;
use IEEE.std_logic_1164.all;
@ -88,6 +79,7 @@ architecture rtl of T65_ALU is
signal SBC_V : std_logic;
signal SBC_N : std_logic;
signal SBC_Q : std_logic_vector(7 downto 0);
signal SBX_Q : std_logic_vector(7 downto 0);
begin
@ -146,7 +138,7 @@ begin
Op=ALU_OP_SBC or --"0111"
Op=ALU_OP_ROL or --"1001"
Op=ALU_OP_ROR or --"1011"
Op=ALU_OP_EQ3 or --"1101"
-- Op=ALU_OP_EQ3 or --"1101"
Op=ALU_OP_INC --"1111"
) then
CT:='1';
@ -156,10 +148,10 @@ begin
AL := resize(unsigned(BusA(3 downto 0) & C), 7) - resize(unsigned(BusB(3 downto 0) & "1"), 6);
AH := resize(unsigned(BusA(7 downto 4) & "0"), 6) - resize(unsigned(BusB(7 downto 4) & AL(5)), 6);
-- pragma translate_off
if is_x(std_logic_vector(AL)) then AL := "0000000"; end if;
if is_x(std_logic_vector(AH)) then AH := "000000"; end if;
-- pragma translate_on
-- pragma translate_off
if is_x(std_logic_vector(AL)) then AL := "0000000"; end if;
if is_x(std_logic_vector(AH)) then AH := "000000"; end if;
-- pragma translate_on
if AL(4 downto 1) = 0 and AH(4 downto 1) = 0 then
SBC_Z <= '1';
@ -171,6 +163,8 @@ begin
SBC_V <= (AH(4) xor BusA(7)) and (BusA(7) xor BusB(7));
SBC_N <= AH(4);
SBX_Q <= std_logic_vector(AH(4 downto 1) & AL(4 downto 1));
if P_In(Flag_D) = '1' then
if AL(5) = '1' then
AL(5 downto 1) := AL(5 downto 1) - 6;
@ -186,79 +180,114 @@ begin
process (Op, P_In, BusA, BusB,
ADC_Z, ADC_C, ADC_V, ADC_N, ADC_Q,
SBC_Z, SBC_C, SBC_V, SBC_N, SBC_Q)
SBC_Z, SBC_C, SBC_V, SBC_N, SBC_Q,
SBX_Q)
variable Q_t : std_logic_vector(7 downto 0);
variable Q2_t : std_logic_vector(7 downto 0);
begin
-- ORA, AND, EOR, ADC, NOP, LD, CMP, SBC
-- ASL, ROL, LSR, ROR, BIT, LD, DEC, INC
P_Out <= P_In;
Q_t := BusA;
Q_t := BusA;
Q2_t := BusA;
case Op is
when ALU_OP_OR=>
Q_t := BusA or BusB;
when ALU_OP_AND=>
Q_t := BusA and BusB;
when ALU_OP_EOR=>
Q_t := BusA xor BusB;
when ALU_OP_ADC=>
P_Out(Flag_V) <= ADC_V;
P_Out(Flag_C) <= ADC_C;
Q_t := ADC_Q;
when ALU_OP_EQ2|ALU_OP_EQ3=>
-- LDA
when ALU_OP_CMP=>
P_Out(Flag_C) <= SBC_C;
when ALU_OP_SBC=>
P_Out(Flag_V) <= SBC_V;
P_Out(Flag_C) <= SBC_C;
Q_t := SBC_Q;
when ALU_OP_ASL=>
Q_t := BusA(6 downto 0) & "0";
P_Out(Flag_C) <= BusA(7);
when ALU_OP_ROL=>
Q_t := BusA(6 downto 0) & P_In(Flag_C);
P_Out(Flag_C) <= BusA(7);
when ALU_OP_LSR=>
Q_t := "0" & BusA(7 downto 1);
P_Out(Flag_C) <= BusA(0);
when ALU_OP_ROR=>
Q_t := P_In(Flag_C) & BusA(7 downto 1);
P_Out(Flag_C) <= BusA(0);
when ALU_OP_BIT=>
P_Out(Flag_V) <= BusB(6);
when ALU_OP_DEC=>
Q_t := std_logic_vector(unsigned(BusA) - 1);
when ALU_OP_INC=>
Q_t := std_logic_vector(unsigned(BusA) + 1);
when others =>
--EQ1,EQ2,EQ3 passes BusA to Q_t
when ALU_OP_OR=>
Q_t := BusA or BusB;
when ALU_OP_AND=>
Q_t := BusA and BusB;
when ALU_OP_EOR=>
Q_t := BusA xor BusB;
when ALU_OP_ADC=>
P_Out(Flag_V) <= ADC_V;
P_Out(Flag_C) <= ADC_C;
Q_t := ADC_Q;
when ALU_OP_CMP=>
P_Out(Flag_C) <= SBC_C;
when ALU_OP_SAX=>
P_Out(Flag_C) <= SBC_C;
Q_t := SBX_Q; -- undoc: subtract (A & X) - (immediate)
when ALU_OP_SBC=>
P_Out(Flag_V) <= SBC_V;
P_Out(Flag_C) <= SBC_C;
Q_t := SBC_Q; -- undoc: subtract (A & X) - (immediate), then decimal correction
when ALU_OP_ASL=>
Q_t := BusA(6 downto 0) & "0";
P_Out(Flag_C) <= BusA(7);
when ALU_OP_ROL=>
Q_t := BusA(6 downto 0) & P_In(Flag_C);
P_Out(Flag_C) <= BusA(7);
when ALU_OP_LSR=>
Q_t := "0" & BusA(7 downto 1);
P_Out(Flag_C) <= BusA(0);
when ALU_OP_ROR=>
Q_t := P_In(Flag_C) & BusA(7 downto 1);
P_Out(Flag_C) <= BusA(0);
when ALU_OP_ARR=>
Q_t := P_In(Flag_C) & (BusA(7 downto 1) and BusB(7 downto 1));
P_Out(Flag_V) <= Q_t(5) xor Q_t(6);
Q2_t := Q_t;
if P_In(Flag_D)='1' then
if (BusA(3 downto 0) and BusB(3 downto 0)) > "0100" then
Q2_t(3 downto 0) := std_logic_vector(unsigned(Q_t(3 downto 0)) + x"6");
end if;
if (BusA(7 downto 4) and BusB(7 downto 4)) > "0100" then
Q2_t(7 downto 4) := std_logic_vector(unsigned(Q_t(7 downto 4)) + x"6");
P_Out(Flag_C) <= '1';
else
P_Out(Flag_C) <= '0';
end if;
else
P_Out(Flag_C) <= Q_t(6);
end if;
when ALU_OP_BIT=>
P_Out(Flag_V) <= BusB(6);
when ALU_OP_DEC=>
Q_t := std_logic_vector(unsigned(BusA) - 1);
when ALU_OP_INC=>
Q_t := std_logic_vector(unsigned(BusA) + 1);
when others =>
null;
--EQ1,EQ2,EQ3 passes BusA to Q_t and P_in to P_out
end case;
case Op is
when ALU_OP_ADC=>
P_Out(Flag_N) <= ADC_N;
P_Out(Flag_Z) <= ADC_Z;
when ALU_OP_CMP|ALU_OP_SBC=>
P_Out(Flag_N) <= SBC_N;
P_Out(Flag_Z) <= SBC_Z;
when ALU_OP_EQ1=>
when ALU_OP_BIT=>
P_Out(Flag_N) <= BusB(7);
if (BusA and BusB) = "00000000" then
P_Out(Flag_Z) <= '1';
else
P_Out(Flag_Z) <= '0';
end if;
when others =>
P_Out(Flag_N) <= Q_t(7);
if Q_t = "00000000" then
P_Out(Flag_Z) <= '1';
else
P_Out(Flag_Z) <= '0';
end if;
when ALU_OP_ADC=>
P_Out(Flag_N) <= ADC_N;
P_Out(Flag_Z) <= ADC_Z;
when ALU_OP_CMP|ALU_OP_SBC|ALU_OP_SAX=>
P_Out(Flag_N) <= SBC_N;
P_Out(Flag_Z) <= SBC_Z;
when ALU_OP_EQ1=>--dont touch P
when ALU_OP_BIT=>
P_Out(Flag_N) <= BusB(7);
if (BusA and BusB) = "00000000" then
P_Out(Flag_Z) <= '1';
else
P_Out(Flag_Z) <= '0';
end if;
when ALU_OP_ANC=>
P_Out(Flag_N) <= Q_t(7);
P_Out(Flag_C) <= Q_t(7);
if Q_t = "00000000" then
P_Out(Flag_Z) <= '1';
else
P_Out(Flag_Z) <= '0';
end if;
when others =>
P_Out(Flag_N) <= Q_t(7);
if Q_t = "00000000" then
P_Out(Flag_Z) <= '1';
else
P_Out(Flag_Z) <= '0';
end if;
end case;
Q <= Q_t;
if Op=ALU_OP_ARR then
-- handled above in ARR code
Q <= Q2_t;
else
Q <= Q_t;
end if;
end process;
end;

2325
src/T6502/T65_MCode.vhd
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File diff suppressed because it is too large Load Diff

172
src/T6502/T65_Pack.vhd
View File

@ -1,20 +1,18 @@
-- ****
-- T65(b) core. In an effort to merge and maintain bug fixes ....
--
--
-- Ver 303 ost(ML) July 2014
-- "magic" constants converted to vhdl types
-- Ver 300 Bugfixes by ehenciak added
-- MikeJ March 2005
-- Latest version from www.fpgaarcade.com (original www.opencores.org)
-- See list of changes in T65 top file (T65.vhd)...
--
-- ****
--
-- 65xx compatible microprocessor core
--
-- Version : 0246
-- FPGAARCADE SVN: $Id: T65_Pack.vhd 1234 2015-02-28 20:14:50Z wolfgang.scherr $
--
-- Copyright (c) 2002 Daniel Wallner (jesus@opencores.org)
-- 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
--
@ -44,17 +42,12 @@
-- 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, but before you do so, please
-- 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.
--
-- The latest version of this file can be found at:
-- http://www.opencores.org/cvsweb.shtml/t65/
--
-- Limitations :
--
-- File history :
--
-- See in T65 top file (T65.vhd)...
library IEEE;
use IEEE.std_logic_1164.all;
@ -70,6 +63,18 @@ package T65_Pack is
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,
@ -78,15 +83,21 @@ package T65_Pack is
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_S,
Set_Addr_To_AD,
Set_Addr_To_PBR,
Set_Addr_To_SP,
Set_Addr_To_ZPG,
Set_Addr_To_BA
);
type T_Write_Data is
(
Write_Data_DL,
@ -97,74 +108,73 @@ package T65_Pack is
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_UNDEF--"----"--may be replaced with any?
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?
);
component T65_MCode
port(
Mode : in std_logic_vector(1 downto 0); -- "00" => 6502, "01" => 65C02, "10" => 65816
IR : in std_logic_vector(7 downto 0);
MCycle : in std_logic_vector(2 downto 0);
P : in std_logic_vector(7 downto 0);
LCycle : out std_logic_vector(2 downto 0);
ALU_Op : out T_ALU_Op;
Set_BusA_To : out T_Set_BusA_To;-- DI,A,X,Y,S,P
Set_Addr_To : out T_Set_Addr_To;-- PC Adder,S,AD,BA
Write_Data : out T_Write_Data;-- DL,A,X,Y,S,P,PCL,PCH
Jump : out std_logic_vector(1 downto 0); -- PC,++,DIDL,Rel
BAAdd : out std_logic_vector(1 downto 0); -- None,DB Inc,BA Add,BA Adj
BreakAtNA : out std_logic;
ADAdd : out std_logic;
AddY : out std_logic;
PCAdd : out std_logic;
Inc_S : out std_logic;
Dec_S : out std_logic;
LDA : out std_logic;
LDP : out std_logic;
LDX : out std_logic;
LDY : out std_logic;
LDS : out std_logic;
LDDI : out std_logic;
LDALU : out std_logic;
LDAD : out std_logic;
LDBAL : out std_logic;
LDBAH : out std_logic;
SaveP : out std_logic;
ALUmore : out std_logic;
Write : out std_logic
);
end component;
component T65_ALU
port(
Mode : in std_logic_vector(1 downto 0); -- "00" => 6502, "01" => 65C02, "10" => 65C816
Op : in T_ALU_Op;
BusA : in std_logic_vector(7 downto 0);
BusB : in std_logic_vector(7 downto 0);
P_In : in std_logic_vector(7 downto 0);
P_Out : out std_logic_vector(7 downto 0);
Q : out std_logic_vector(7 downto 0)
);
end component;
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;