mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2024-11-19 02:08:25 +00:00
103 lines
2.1 KiB
C++
103 lines
2.1 KiB
C++
#pragma once
|
|
|
|
#include <array>
|
|
#include <cstdint>
|
|
#include <string>
|
|
|
|
#include "Signal.h"
|
|
#include "AddressEventArgs.h"
|
|
|
|
#if defined(_M_X64) || defined(_M_IX86 )
|
|
# define HOST_LITTLE_ENDIAN
|
|
#else
|
|
# define HOST_BIG_ENDIAN
|
|
#endif
|
|
|
|
namespace EightBit {
|
|
|
|
typedef union {
|
|
struct {
|
|
#ifdef HOST_LITTLE_ENDIAN
|
|
uint8_t low;
|
|
uint8_t high;
|
|
#endif
|
|
#ifdef HOST_BIG_ENDIAN
|
|
uint8_t high;
|
|
uint8_t low;
|
|
#endif
|
|
};
|
|
uint16_t word;
|
|
} register16_t;
|
|
|
|
class Memory {
|
|
public:
|
|
|
|
static uint8_t highByte(uint16_t value) {
|
|
return value >> 8;
|
|
}
|
|
|
|
static uint8_t lowByte(uint16_t value) {
|
|
return value & 0xff;
|
|
}
|
|
|
|
Memory(uint16_t addressMask);
|
|
|
|
// Only fired with read/write methods
|
|
Signal<AddressEventArgs> WrittenByte;
|
|
Signal<AddressEventArgs> ReadingByte;
|
|
|
|
register16_t& ADDRESS() { return m_address; }
|
|
uint8_t& DATA() { return *m_data; }
|
|
|
|
uint8_t& placeDATA(uint8_t value) {
|
|
m_temporary = value;
|
|
m_data = &m_temporary;
|
|
return DATA();
|
|
}
|
|
|
|
uint8_t& referenceDATA(uint8_t& value) {
|
|
m_data = &value;
|
|
return DATA();
|
|
}
|
|
|
|
virtual uint8_t peek(uint16_t address) const;
|
|
virtual uint16_t peekWord(uint16_t address) const;
|
|
|
|
virtual uint8_t& reference() {
|
|
auto effective = effectiveAddress(ADDRESS().word);
|
|
return m_locked[effective] ? placeDATA(m_bus[effective]) : referenceDATA(m_bus[effective]);
|
|
}
|
|
|
|
virtual uint16_t effectiveAddress(uint16_t address) const {
|
|
return address & m_addressMask;
|
|
}
|
|
|
|
uint8_t read(uint16_t offset) {
|
|
ADDRESS().word = offset;
|
|
const auto content = reference();
|
|
ReadingByte.fire(AddressEventArgs(offset, content));
|
|
return content;
|
|
}
|
|
|
|
void write(uint16_t offset, uint8_t value) {
|
|
ADDRESS().word = offset;
|
|
reference() = value;
|
|
WrittenByte.fire(AddressEventArgs(offset, value));
|
|
}
|
|
|
|
void clear();
|
|
void loadRom(const std::string& path, uint16_t offset);
|
|
void loadRam(const std::string& path, uint16_t offset);
|
|
|
|
protected:
|
|
std::array<uint8_t, 0x10000> m_bus;
|
|
std::array<bool, 0x10000> m_locked;
|
|
|
|
uint16_t m_addressMask; // Mirror
|
|
uint8_t m_temporary; // Used to simulate ROM
|
|
register16_t m_address;
|
|
uint8_t* m_data;
|
|
|
|
int loadMemory(const std::string& path, uint16_t offset);
|
|
};
|
|
} |