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FDS: Improved IRQ emulation (based on hardware tests)

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This commit is contained in:
Souryo 2017-09-23 12:07:57 -04:00
parent 5b2467b205
commit 3a02d6cd50
2 changed files with 24 additions and 25 deletions
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46
Core/FDS.cpp
View file

@ -62,20 +62,15 @@ void FDS::WriteFdsDisk(uint8_t value)
void FDS::ClockIrq()
{
if(_needIrq) {
CPU::SetIRQSource(IRQSource::External);
_needIrq = false;
}
if(_irqEnabled && _irqCounter > 0) {
_irqCounter--;
if(_irqEnabled) {
if(_irqCounter == 0) {
_needIrq = true;
if(_irqReloadEnabled) {
_irqCounter = _irqReloadValue;
} else {
CPU::SetIRQSource(IRQSource::External);
_irqCounter = _irqReloadValue;
if(!_irqRepeatEnabled) {
_irqEnabled = false;
}
} else {
_irqCounter--;
}
}
}
@ -308,29 +303,32 @@ void FDS::WriteRegister(uint16_t addr, uint8_t value)
switch(addr) {
case 0x4020:
_irqReloadValue = (_irqReloadValue & 0xFF00) | value;
CPU::ClearIRQSource(IRQSource::External);
break;
case 0x4021:
_irqReloadValue = (_irqReloadValue & 0x00FF) | (value << 8);
CPU::ClearIRQSource(IRQSource::External);
break;
case 0x4022:
_irqReloadEnabled = (value & 0x01) == 0x01;
_irqEnabled = (value & 0x02) == 0x02;
_irqCounter = _irqReloadValue;
if(_irqEnabled && !_irqReloadEnabled) {
//Needed by Kaettekita Mario Bros
//If done when _irqEnabled is false, Lutter breaks
_irqReloadValue = 0;
_irqRepeatEnabled = (value & 0x01) == 0x01;
_irqEnabled = (value & 0x02) == 0x02 && _diskRegEnabled;
if(_irqEnabled) {
_irqCounter = _irqReloadValue;
} else {
CPU::ClearIRQSource(IRQSource::External);
}
CPU::ClearIRQSource(IRQSource::External);
break;
case 0x4023:
_diskRegEnabled = (value & 0x01) == 0x01;
_soundRegEnabled = (value & 0x02) == 0x02;
if(!_diskRegEnabled) {
_irqEnabled = false;
CPU::ClearIRQSource(IRQSource::External);
CPU::ClearIRQSource(IRQSource::FdsDisk);
}
break;
case 0x4024:
@ -430,10 +428,12 @@ void FDS::StreamState(bool saving)
{
BaseMapper::StreamState(saving);
bool unusedNeedIrq = false;
SnapshotInfo audio{ _audio.get() };
Stream(_irqReloadValue, _irqCounter, _irqEnabled, _irqReloadEnabled, _diskRegEnabled, _soundRegEnabled, _writeDataReg, _motorOn, _resetTransfer,
Stream(_irqReloadValue, _irqCounter, _irqEnabled, _irqRepeatEnabled, _diskRegEnabled, _soundRegEnabled, _writeDataReg, _motorOn, _resetTransfer,
_readMode, _crcControl, _diskReady, _diskIrqEnabled, _extConWriteReg, _badCrc, _endOfHead, _readWriteEnabled, _readDataReg, _diskWriteProtected,
_diskNumber, _newDiskNumber, _newDiskInsertDelay, _diskPosition, _delay, _previousCrcControlFlag, _gapEnded, _scanningDisk, _needIrq,
_diskNumber, _newDiskNumber, _newDiskInsertDelay, _diskPosition, _delay, _previousCrcControlFlag, _gapEnded, _scanningDisk, unusedNeedIrq,
_transferComplete, _isDirty, audio);
if(!saving) {

3
Core/FDS.h
View file

@ -24,7 +24,7 @@ private:
uint16_t _irqReloadValue = 0;
uint16_t _irqCounter = 0;
bool _irqEnabled = false;
bool _irqReloadEnabled = false;
bool _irqRepeatEnabled = false;
bool _diskRegEnabled = true;
bool _soundRegEnabled = true;
@ -62,7 +62,6 @@ private:
bool _previousCrcControlFlag = false;
bool _gapEnded = true;
bool _scanningDisk = false;
bool _needIrq = false;
bool _transferComplete = false;
bool _isDirty = false;