Mesen/Core/TaitoTc0690.h
2016-07-16 23:19:02 -04:00

83 lines
1.6 KiB
C++

#pragma once
#include "stdafx.h"
#include "TaitoTc0190.h"
#include "MMC3.h"
class TaitoTc0690 : public MMC3
{
private:
uint8_t _irqDelay;
protected:
virtual void InitMapper()
{
_irqDelay = 0;
SelectPRGPage(2, -2);
SelectPRGPage(3, -1);
}
virtual void StreamState(bool saving)
{
MMC3::StreamState(saving);
Stream(_irqDelay);
}
virtual void TriggerIrq()
{
//"The IRQ seems to trip a little later than it does on MMC3. It looks like about a 4 CPU cycle delay from the normal MMC3 IRQ time."
//A value of 5 removes the shaking from The Jetsons
_irqDelay = 5;
}
void ProcessCpuClock()
{
if(_irqDelay > 0) {
_irqDelay--;
if(_irqDelay == 0) {
CPU::SetIRQSource(IRQSource::External);
}
}
}
virtual void WriteRegister(uint16_t addr, uint8_t value)
{
switch(addr & 0xE003) {
case 0x8000:
SelectPRGPage(0, value & 0x3F);
break;
case 0x8001:
SelectPRGPage(1, value & 0x3F);
break;
case 0x8002:
SelectCHRPage(0, value * 2);
SelectCHRPage(1, value * 2 + 1);
break;
case 0x8003:
SelectCHRPage(2, value * 2);
SelectCHRPage(3, value * 2 + 1);
break;
case 0xA000: case 0xA001: case 0xA002: case 0xA003:
SelectCHRPage(4 + (addr & 0x03), value);
break;
case 0xC000:
_irqReloadValue = (0x100 - value) & 0xFF;
break;
case 0xC001:
_irqCounter = 0;
_irqReload = true;
break;
case 0xC002:
_irqEnabled = true;
break;
case 0xC003:
_irqEnabled = false;
CPU::ClearIRQSource(IRQSource::External);
break;
case 0xE000:
SetMirroringType((value & 0x40) == 0x40 ? MirroringType::Horizontal : MirroringType::Vertical);
break;
}
}
};