Mesen2/Core/NES/Mappers/Unlicensed/Mapper106.h
2024-10-01 20:57:06 +09:00

75 lines
No EOL
1.6 KiB
C++

#pragma once
#include "pch.h"
#include "NES/BaseMapper.h"
#include "NES/NesCpu.h"
#include "NES/NesConsole.h"
class Mapper106 : public BaseMapper
{
private:
uint16_t _irqCounter = 0;
bool _irqEnabled = false;
protected:
uint16_t GetPrgPageSize() override { return 0x2000; }
uint16_t GetChrPageSize() override { return 0x400; }
bool EnableCpuClockHook() override { return true; }
void InitMapper() override
{
_irqEnabled = false;
_irqCounter = 0;
SelectPrgPage(0, -1);
SelectPrgPage(1, -1);
SelectPrgPage(2, -1);
SelectPrgPage(3, -1);
}
void Serialize(Serializer& s) override
{
BaseMapper::Serialize(s);
SV(_irqCounter);
SV(_irqEnabled);
}
void ProcessCpuClock() override
{
BaseProcessCpuClock();
if(_irqEnabled) {
_irqCounter++;
if(_irqCounter == 0) {
_console->GetCpu()->SetIrqSource(IRQSource::External);
_irqEnabled = false;
}
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
switch(addr & 0x0F) {
case 0: case 2: SelectChrPage(addr & 0x0F, value & 0xFE); break;
case 1: case 3: SelectChrPage(addr & 0x0F, value | 0x01); break;
case 4: case 5: case 6: case 7: SelectChrPage(addr & 0x0F, value); break;
case 8: case 0x0B: SelectPrgPage((addr & 0x0F) - 8, (value & 0x0F) | 0x10); break;
case 9: case 0x0A: SelectPrgPage((addr & 0x0F) - 8, value & 0x1F); break;
case 0x0D:
_irqEnabled = false;
_irqCounter = 0;
_console->GetCpu()->ClearIrqSource(IRQSource::External);
break;
case 0x0E:
_irqCounter = (_irqCounter & 0xFF00) | value;
break;
case 0x0F:
_irqCounter = (_irqCounter & 0xFF) | (value << 8);
_irqEnabled = true;
break;
}
}
};