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https://github.com/bsnes-emu/bsnes.git
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50411a17d1
byuu says:
Changelog:
- md/ym2612: initialize DAC sample to center volume [Cydrak]
- processor/arm: add accumulate mode extra cycle to mlal [Jonas
Quinn]
- processor/huc6280: split off algorithms, improve naming of functions
- processor/mos6502: split off algorithms
- processor/spc700: major revamp of entire core (~50% completed)
- processor/wdc65816: fixed several bugs introduced by rewrite
For the SPC700, this turns out to be very old code as well, with global
object state variables, those annoying `{Boolean,Natural}BitField` types,
`under_case` naming conventions, heavily abbreviated function names, etc.
I'm working to get the code to be in the same design as the MOS6502,
HuC6280, WDC65816 cores, since they're all extremely similar in terms of
architectural design (the SPC700 is more of an off-label
reimplementation of a 6502 core, but still.)
The main thing left is that about 90% of the actual instructions still
need to be adapted to not use the internal state (`aa`, `rd`, `dp`,
`sp`, `bit` variables.) I wanted to finish this today, but ran out of
time before work.
I wouldn't suggest too much testing just yet. We should wait until the
SPC700 core is finished for that. However, if some does want to and
spots regressions, please let me know.
132 lines
3.9 KiB
C++
132 lines
3.9 KiB
C++
//MOS Technologies MOS6502
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#pragma once
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namespace Processor {
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struct MOS6502 {
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virtual auto read(uint16 addr) -> uint8 = 0;
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virtual auto write(uint16 addr, uint8 data) -> void = 0;
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virtual auto lastCycle() -> void = 0;
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virtual auto nmi(uint16& vector) -> void = 0;
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virtual auto readDebugger(uint16 addr) -> uint8 { return 0; }
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//mos6502.cpp
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auto mdr() const -> uint8;
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auto power() -> void;
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//memory.cpp
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auto idle() -> void;
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auto idlePageCrossed(uint16, uint16) -> void;
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auto idlePageAlways(uint16, uint16) -> void;
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auto opcode() -> uint8;
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auto operand() -> uint8;
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auto load(uint8 addr) -> uint8;
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auto store(uint8 addr, uint8 data) -> void;
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auto push(uint8 data) -> void;
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auto pull() -> uint8;
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//algorithms.cpp
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using fp = auto (MOS6502::*)(uint8) -> uint8;
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auto algorithmADC(uint8) -> uint8;
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auto algorithmAND(uint8) -> uint8;
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auto algorithmASL(uint8) -> uint8;
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auto algorithmBIT(uint8) -> uint8;
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auto algorithmCMP(uint8) -> uint8;
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auto algorithmCPX(uint8) -> uint8;
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auto algorithmCPY(uint8) -> uint8;
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auto algorithmDEC(uint8) -> uint8;
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auto algorithmEOR(uint8) -> uint8;
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auto algorithmINC(uint8) -> uint8;
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auto algorithmLD (uint8) -> uint8;
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auto algorithmLSR(uint8) -> uint8;
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auto algorithmORA(uint8) -> uint8;
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auto algorithmROL(uint8) -> uint8;
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auto algorithmROR(uint8) -> uint8;
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auto algorithmSBC(uint8) -> uint8;
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//instruction.cpp
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auto interrupt() -> void;
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auto instruction() -> void;
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//instructions.cpp
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auto instructionAbsoluteModify(fp alu) -> void;
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auto instructionAbsoluteModify(fp alu, uint8 index) -> void;
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auto instructionAbsoluteRead(fp alu, uint8& data) -> void;
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auto instructionAbsoluteRead(fp alu, uint8& data, uint8 index) -> void;
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auto instructionAbsoluteWrite(uint8& data) -> void;
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auto instructionAbsoluteWrite(uint8& data, uint8 index) -> void;
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auto instructionBranch(bool take) -> void;
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auto instructionClear(bool& flag) -> void;
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auto instructionImmediate(fp alu, uint8& data) -> void;
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auto instructionImplied(fp alu, uint8& data) -> void;
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auto instructionIndirectXRead(fp alu, uint8& data) -> void;
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auto instructionIndirectXWrite(uint8& data) -> void;
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auto instructionIndirectYRead(fp alu, uint8& data) -> void;
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auto instructionIndirectYWrite(uint8& data) -> void;
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auto instructionPull(uint8& data) -> void;
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auto instructionPush(uint8& data) -> void;
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auto instructionSet(bool& flag) -> void;
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auto instructionTransfer(uint8& source, uint8& target, bool flag) -> void;
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auto instructionZeroPageModify(fp alu) -> void;
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auto instructionZeroPageModify(fp alu, uint8 index) -> void;
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auto instructionZeroPageRead(fp alu, uint8& data) -> void;
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auto instructionZeroPageRead(fp alu, uint8& data, uint8 index) -> void;
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auto instructionZeroPageWrite(uint8& data) -> void;
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auto instructionZeroPageWrite(uint8& data, uint8 index) -> void;
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auto instructionBRK() -> void;
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auto instructionJMPAbsolute() -> void;
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auto instructionJMPIndirect() -> void;
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auto instructionJSRAbsolute() -> void;
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auto instructionNOP() -> void;
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auto instructionPHP() -> void;
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auto instructionPLP() -> void;
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auto instructionRTI() -> void;
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auto instructionRTS() -> void;
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//serialization.cpp
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auto serialize(serializer&) -> void;
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//disassembler.cpp
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auto disassemble(uint16 pc) -> string;
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//set to false to disable BCD mode in ADC, SBC instructions
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bool BCD = true;
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struct Flags {
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bool c; //carry
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bool z; //zero
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bool i; //interrupt disable
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bool d; //decimal mode
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bool v; //overflow
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bool n; //negative
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inline operator uint() const {
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return c << 0 | z << 1 | i << 2 | d << 3 | v << 6 | n << 7;
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}
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inline auto& operator=(uint8 data) {
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c = data.bit(0);
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z = data.bit(1);
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i = data.bit(2);
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d = data.bit(3);
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v = data.bit(6);
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n = data.bit(7);
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return *this;
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}
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};
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struct Registers {
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uint8 a;
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uint8 x;
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uint8 y;
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uint8 s;
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uint16 pc;
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Flags p;
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uint8 mdr;
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} r;
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};
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}
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