mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2025-08-09 00:25:10 +00:00
304 lines
9.5 KiB
C++
304 lines
9.5 KiB
C++
#pragma once
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#include <cstdint>
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#include <array>
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#include <functional>
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#include <IntelProcessor.h>
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#include <EventArgs.h>
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#include <Signal.h>
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#include <Register.h>
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namespace EightBit {
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class Bus;
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class Z80 final : public IntelProcessor {
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public:
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struct refresh_t {
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bool high : 1;
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uint8_t variable : 7;
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refresh_t(const uint8_t value)
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: high(!!(value & Bit7)),
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variable(value & Mask7)
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{ }
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operator uint8_t() const {
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return (high << 7) | variable;
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}
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auto& operator++() {
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++variable;
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return *this;
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}
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};
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enum StatusBits {
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SF = Bit7,
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ZF = Bit6,
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YF = Bit5,
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HC = Bit4,
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XF = Bit3,
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PF = Bit2,
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VF = Bit2,
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NF = Bit1,
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CF = Bit0,
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};
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Z80(Bus& bus);
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Signal<Z80> ExecutingInstruction;
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Signal<Z80> ExecutedInstruction;
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Signal<EventArgs> ReadingMemory;
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Signal<EventArgs> ReadMemory;
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Signal<EventArgs> WritingMemory;
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Signal<EventArgs> WrittenMemory;
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Signal<EventArgs> ReadingIO;
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Signal<EventArgs> ReadIO;
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Signal<EventArgs> WritingIO;
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Signal<EventArgs> WrittenIO;
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int execute() final;
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int step() final;
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[[nodiscard]] register16_t& AF() final;
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[[nodiscard]] register16_t& BC() final;
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[[nodiscard]] register16_t& DE() final;
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[[nodiscard]] register16_t& HL() final;
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[[nodiscard]] auto& IX() { return m_ix; }
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[[nodiscard]] auto& IXH() { return IX().high; }
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[[nodiscard]] auto& IXL() { return IX().low; }
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[[nodiscard]] auto& IY() { return m_iy; }
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[[nodiscard]] auto& IYH() { return IY().high; }
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[[nodiscard]] auto& IYL() { return IY().low; }
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// ** From the Z80 CPU User Manual
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// Memory Refresh(R) Register.The Z80 CPU contains a memory refresh counter,
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// enabling dynamic memories to be used with the same ease as static memories.Seven bits
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// of this 8-bit register are automatically incremented after each instruction fetch.The eighth
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// bit remains as programmed, resulting from an LD R, A instruction. The data in the refresh
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// counter is sent out on the lower portion of the address bus along with a refresh control
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// signal while the CPU is decoding and executing the fetched instruction. This mode of refresh
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// is transparent to the programmer and does not slow the CPU operation.The programmer
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// can load the R register for testing purposes, but this register is normally not used by the
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// programmer. During refresh, the contents of the I Register are placed on the upper eight
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// bits of the address bus.
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[[nodiscard]] auto& REFRESH() { return m_refresh; }
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[[nodiscard]] auto& IV() { return iv; }
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[[nodiscard]] auto& IM() { return m_interruptMode; }
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[[nodiscard]] auto& IFF1() { return m_iff1; }
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[[nodiscard]] auto& IFF2() { return m_iff2; }
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void exx() { m_registerSet ^= 1; }
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void exxAF() { m_accumulatorFlagsSet ^= 1; }
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[[nodiscard]] auto requestingIO() const { return lowered(IORQ()); }
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[[nodiscard]] auto requestingMemory() const { return lowered(MREQ()); }
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[[nodiscard]] auto requestingRead() const { return lowered(RD()); }
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[[nodiscard]] auto requestingWrite() const { return lowered(WR()); }
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// ** From the Z80 CPU User Manual
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// RFSH.Refresh(output, active Low). RFSH, together with MREQ, indicates that the lower
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// seven bits of the system<65>s address bus can be used as a refresh address to the system<65>s
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// dynamic memories.
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DECLARE_PIN_OUTPUT(RFSH)
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DECLARE_PIN_INPUT(NMI)
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DECLARE_PIN_OUTPUT(M1)
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DECLARE_PIN_OUTPUT(MREQ)
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DECLARE_PIN_OUTPUT(IORQ)
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DECLARE_PIN_OUTPUT(RD)
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DECLARE_PIN_OUTPUT(WR)
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protected:
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void handleRESET() final;
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void handleINT() final;
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void pushWord(register16_t destination) final;
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void memoryWrite() final;
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uint8_t memoryRead() final;
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void busWrite() final;
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uint8_t busRead() final;
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void jr(int8_t offset) final;
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int jrConditional(int condition) final;
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private:
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DEFINE_PIN_ACTIVATOR_LOW(RFSH)
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DEFINE_PIN_ACTIVATOR_LOW(M1)
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DEFINE_PIN_ACTIVATOR_LOW(MREQ)
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DEFINE_PIN_ACTIVATOR_LOW(IORQ)
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DEFINE_PIN_ACTIVATOR_LOW(RD)
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DEFINE_PIN_ACTIVATOR_LOW(WR)
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enum { BC_IDX, DE_IDX, HL_IDX };
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std::array<std::array<register16_t, 3>, 2> m_registers;
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int m_registerSet = 0;
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std::array<register16_t, 2> m_accumulatorFlags;
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int m_accumulatorFlagsSet = 0;
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register16_t m_ix = 0xffff;
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register16_t m_iy = 0xffff;
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refresh_t m_refresh = 0x7f;
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uint8_t iv = 0xff;
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int m_interruptMode = 0;
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bool m_iff1 = false;
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bool m_iff2 = false;
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bool m_prefixCB = false;
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bool m_prefixDD = false;
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bool m_prefixED = false;
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bool m_prefixFD = false;
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int8_t m_displacement = 0;
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void handleNMI();
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void resetPrefixes();
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[[nodiscard]] auto displaced() const { return m_prefixDD || m_prefixFD; }
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[[nodiscard]] uint16_t displacedAddress();
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void fetchDisplacement();
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[[nodiscard]] uint8_t fetchOpCode();
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uint8_t readBusDataM1();
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typedef std::function<register16_t(void)> addresser_t;
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void loadAccumulatorIndirect(addresser_t addresser);
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void storeAccumulatorIndirect(addresser_t addresser);
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typedef std::function<uint8_t(void)> reader_t;
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void readInternalRegister(reader_t reader);
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[[nodiscard]] register16_t& HL2();
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[[nodiscard]] register16_t& RP(int rp);
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[[nodiscard]] register16_t& RP2(int rp);
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[[nodiscard]] uint8_t R(int r);
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void R(int r, uint8_t value);
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void R2(int r, uint8_t value);
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[[nodiscard]] static uint8_t adjustHalfCarryAdd(uint8_t f, uint8_t before, uint8_t value, int calculation);
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[[nodiscard]] static uint8_t adjustHalfCarrySub(uint8_t f, uint8_t before, uint8_t value, int calculation);
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[[nodiscard]] static uint8_t adjustOverflowAdd(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation);
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[[nodiscard]] static uint8_t adjustOverflowAdd(uint8_t f, int beforeNegative, int valueNegative, int afterNegative);
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[[nodiscard]] static uint8_t adjustOverflowSub(uint8_t f, uint8_t before, uint8_t value, uint8_t calculation);
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[[nodiscard]] static uint8_t adjustOverflowSub(uint8_t f, int beforeNegative, int valueNegative, int afterNegative);
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[[nodiscard]] static bool convertCondition(uint8_t f, int flag);
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static uint8_t subtract(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0);
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void executeCB(int x, int y, int z);
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void executeED(int x, int y, int z, int p, int q);
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void executeOther(int x, int y, int z, int p, int q);
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[[nodiscard]] static uint8_t increment(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t decrement(uint8_t& f, uint8_t operand);
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void di();
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void ei();
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void retn();
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void reti();
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void returnConditionalFlag(uint8_t f, int flag);
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void jrConditionalFlag(uint8_t f, int flag);
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void callConditionalFlag(uint8_t f, int flag);
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void jumpConditionalFlag(uint8_t f, int flag);
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[[nodiscard]] register16_t sbc(uint8_t& f, register16_t operand, register16_t value);
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[[nodiscard]] register16_t adc(uint8_t& f, register16_t operand, register16_t value);
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[[nodiscard]] register16_t add(uint8_t& f, register16_t operand, register16_t value, int carry = 0);
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[[nodiscard]] static uint8_t add(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0);
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[[nodiscard]] static uint8_t adc(uint8_t& f, uint8_t operand, uint8_t value);
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[[nodiscard]] static uint8_t sub(uint8_t& f, uint8_t operand, uint8_t value, int carry = 0);
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[[nodiscard]] static uint8_t sbc(uint8_t& f, uint8_t operand, uint8_t value);
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[[nodiscard]] static uint8_t andr(uint8_t& f, uint8_t operand, uint8_t value);
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[[nodiscard]] static uint8_t xorr(uint8_t& f, uint8_t operand, uint8_t value);
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[[nodiscard]] static uint8_t orr(uint8_t& f, uint8_t operand, uint8_t value);
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static void compare(uint8_t& f, uint8_t operand, uint8_t value);
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[[nodiscard]] static uint8_t rlc(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t rrc(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t rl(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t rr(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t sla(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t sra(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t sll(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t srl(uint8_t& f, uint8_t operand);
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static void bit(uint8_t& f, int n, uint8_t operand);
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[[nodiscard]] static uint8_t res(int n, uint8_t operand);
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[[nodiscard]] static uint8_t set(int n, uint8_t operand);
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[[nodiscard]] static uint8_t daa(uint8_t& f, uint8_t operand);
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static void scf(uint8_t& f, uint8_t operand);
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static void ccf(uint8_t& f, uint8_t operand);
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[[nodiscard]] static uint8_t cpl(uint8_t& f, uint8_t operand);
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void xhtl(register16_t& exchange);
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void blockCompare(uint8_t& f, uint8_t value, register16_t source, register16_t& counter);
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void cpi(uint8_t& f, uint8_t value);
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[[nodiscard]] bool cpir(uint8_t& f, uint8_t value);
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void cpd(uint8_t& f, uint8_t value);
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[[nodiscard]] bool cpdr(uint8_t& f, uint8_t value);
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void blockLoad(uint8_t& f, uint8_t a, register16_t source, register16_t destination, register16_t& counter);
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void ldi(uint8_t& f, uint8_t a);
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[[nodiscard]] bool ldir(uint8_t& f, uint8_t a);
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void ldd(uint8_t& f, uint8_t a);
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[[nodiscard]] bool lddr(uint8_t& f, uint8_t a);
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void blockIn(register16_t& source, register16_t destination);
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void ini();
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[[nodiscard]] bool inir();
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void ind();
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[[nodiscard]] bool indr();
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void blockOut(register16_t source, register16_t& destination);
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void outi();
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[[nodiscard]] bool otir();
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void outd();
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[[nodiscard]] bool otdr();
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[[nodiscard]] uint8_t neg(uint8_t& f, uint8_t operand);
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void rrd(uint8_t& f, register16_t address, uint8_t& update);
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void rld(uint8_t& f, register16_t address, uint8_t& update);
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void portWrite(uint8_t port);
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void portWrite();
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uint8_t portRead(uint8_t port);
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uint8_t portRead();
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};
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} |