Mesen2/Core/NES/Mappers/Whirlwind/Smb2j.h
2024-10-01 20:57:06 +09:00

69 lines
No EOL
1.7 KiB
C++

#pragma once
#include "pch.h"
#include "NES/BaseMapper.h"
#include "NES/NesConsole.h"
#include "NES/NesCpu.h"
class Smb2j : public BaseMapper
{
private:
uint16_t _irqCounter = 0;
bool _irqEnabled = false;
protected:
uint16_t GetPrgPageSize() override { return 0x1000; }
uint16_t GetChrPageSize() override { return 0x2000; }
uint16_t RegisterStartAddress() override { return 0x4122; }
uint16_t RegisterEndAddress() override { return 0x4122; }
bool EnableCpuClockHook() override { return true; }
void InitMapper() override
{
SelectPrgPage4x(0, 0);
SelectPrgPage4x(1, 4);
SelectChrPage(0, 0);
if(_prgSize >= 0x10000) {
AddRegisterRange(0x4022, 0x4022, MemoryOperation::Write);
}
SetCpuMemoryMapping(0x5000, 0x5FFF, GetPrgPageCount() - 3, PrgMemoryType::PrgRom);
SetCpuMemoryMapping(0x6000, 0x6FFF, GetPrgPageCount() - 2, PrgMemoryType::PrgRom);
SetCpuMemoryMapping(0x7000, 0x7FFF, GetPrgPageCount() - 1, PrgMemoryType::PrgRom);
_irqCounter = 0;
_irqEnabled = false;
}
void Serialize(Serializer& s) override
{
BaseMapper::Serialize(s);
SV(_irqCounter);
SV(_irqEnabled);
}
void ProcessCpuClock() override
{
BaseProcessCpuClock();
if(_irqEnabled) {
_irqCounter = (_irqCounter + 1) & 0xFFF;
if(_irqCounter == 0) {
_irqEnabled = false;
_console->GetCpu()->SetIrqSource(IRQSource::External);
}
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
if(addr == 0x4022) {
SelectPrgPage4x(0, (value & 0x01) << 2);
SelectPrgPage4x(1, ((value & 0x01) << 2) + 4);
} else if(addr == 0x4122) {
_irqEnabled = (value & 0x03) != 0;
_irqCounter = 0;
_console->GetCpu()->ClearIrqSource(IRQSource::External);
}
}
};