Mesen/Core/UnlBj56.h
2023-05-12 20:37:50 -05:00

60 lines
1.2 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class UnlBj56 : public BaseMapper
{
private:
uint16_t _irqCounter;
protected:
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
virtual uint16_t GetCHRPageSize() override { return 0x400; }
void InitMapper() override
{
_irqCounter = 0;
SelectPRGPage(0, -4);
SelectPRGPage(1, -3);
SelectPRGPage(2, -2);
SelectPRGPage(3, -1);
SetMirroringType(MirroringType::Vertical);
RemoveRegisterRange(0x9000, 0xFFFF, MemoryOperation::Write);
}
void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
Stream(_irqCounter);
}
void ProcessCpuClock() override
{
_irqCounter++;
if(_irqCounter & 4096) {
_console->GetCpu()->SetIrqSource(IRQSource::External);
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
switch(addr & 0xF) {
case 0: case 1: case 2: case 3:
case 4: case 5: case 6: case 7:
SelectCHRPage(addr & 0x07, value);
break;
case 8: case 9: case 0xA: case 0xB:
SelectPRGPage(addr & 0x03, value);
break;
case 0xD: case 0xF:
_irqCounter = 0;
_console->GetCpu()->ClearIrqSource(IRQSource::External);
break;
}
}
};