mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2024-12-23 00:29:47 +00:00
112 lines
2.6 KiB
C++
112 lines
2.6 KiB
C++
#pragma once
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#include <cstdint>
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#include "Chip.h"
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#include "Bus.h"
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#include "Register.h"
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#include "EightBitCompilerDefinitions.h"
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namespace EightBit {
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class Processor : public Chip {
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public:
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// b: number of bits representing the number in x
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// x: sign extend this b-bit number to r
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static int8_t signExtend(int b, uint8_t x);
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auto& PC() { return m_pc; }
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auto& RESET() { return m_resetLine; }
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auto& HALT() { return m_haltLine; }
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auto& INT() { return m_intLine; }
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auto& IRQ() { return INT(); } // Synonym
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virtual void powerOn() override;
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void reset() { lower(RESET()); }
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int run(int limit);
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virtual int step() = 0;
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virtual int execute(uint8_t opcode) = 0;
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auto cycles() const { return m_cycles; }
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virtual register16_t peekWord(register16_t address) = 0;
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virtual void pokeWord(register16_t address, register16_t value) = 0;
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protected:
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Processor(Bus& memory);
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virtual ~Processor() = default;
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auto& BUS() { return m_bus; }
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auto halted() { return lowered(HALT()); }
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auto halt() { --PC(); lower(HALT()); }
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auto proceed() { ++PC(); raise(HALT()); }
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virtual void handleRESET();
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virtual void handleINT();
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virtual void handleIRQ();
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auto getBytePaged(const uint8_t page, const uint8_t offset) {
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return BUS().read(register16_t(offset, page));
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}
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void setBytePaged(const uint8_t page, const uint8_t offset, const uint8_t value) {
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BUS().write(register16_t(offset, page), value);
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}
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auto fetchByte() {
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return BUS().read(PC()++);
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}
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virtual register16_t getWord() = 0;
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virtual void setWord(register16_t value) = 0;
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virtual register16_t getWordPaged(uint8_t page, uint8_t offset) = 0;
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virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value) = 0;
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virtual register16_t fetchWord() = 0;
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virtual void push(uint8_t value) = 0;
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virtual uint8_t pop() = 0;
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virtual void pushWord(register16_t value) = 0;
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virtual register16_t popWord() = 0;
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auto getWord(const register16_t address) {
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BUS().ADDRESS() = address;
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return getWord();
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}
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void setWord(const register16_t address, const register16_t value) {
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BUS().ADDRESS() = address;
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return setWord(value);
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}
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void jump(const register16_t destination) {
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PC() = destination;
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}
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void call(const register16_t destination) {
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pushWord(PC());
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jump(destination);
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}
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virtual void ret();
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void resetCycles() { m_cycles = 0; }
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void addCycles(const int extra) { m_cycles += extra; }
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void addCycle() { ++m_cycles; }
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private:
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Bus& m_bus;
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int m_cycles = 0;
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register16_t m_pc;
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PinLevel m_intLine = Low;
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PinLevel m_haltLine = Low;
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PinLevel m_resetLine = Low;
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};
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}
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