Mesen/Core/Mapper106.h

69 lines
1.5 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class Mapper106 : public BaseMapper
{
private:
uint16_t _irqCounter;
bool _irqEnabled;
protected:
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
virtual uint16_t GetCHRPageSize() override { return 0x400; }
void InitMapper() override
{
_irqEnabled = false;
_irqCounter = 0;
SelectPRGPage(0, -1);
SelectPRGPage(1, -1);
SelectPRGPage(2, -1);
SelectPRGPage(3, -1);
}
void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
Stream(_irqCounter, _irqEnabled);
}
void ProcessCpuClock() override
{
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;
}
}
};