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improved MBC3 overall performance
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@drhelius
drhelius committed Oct 28, 2012
1 parent f0e0164 commit 336f79a
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Showing 2 changed files with 139 additions and 116 deletions.
253 changes: 137 additions & 116 deletions src/MBC3MemoryRule.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -40,158 +40,177 @@ MBC3MemoryRule::~MBC3MemoryRule()

u8 MBC3MemoryRule::PerformRead(u16 address)
{
if (address >= 0x4000 && address < 0x8000)
switch (address & 0xE000)
{
u8* pROM = m_pCartridge->GetTheROM();
return pROM[(address - 0x4000) + (0x4000 * m_iCurrentROMBank)];
}
else if (address >= 0xA000 && address < 0xC000)
{
if (m_iCurrentRAMBank >= 0)
case 0x4000:
case 0x6000:
{
u8* pROM = m_pCartridge->GetTheROM();
return pROM[(address - 0x4000) + m_CurrentROMAddress];
}
case 0xA000:
{
if (m_bRamEnabled)
if (m_iCurrentRAMBank >= 0)
{
return m_pRAMBanks[(address - 0xA000) + (0x2000 * m_iCurrentRAMBank)];
if (m_bRamEnabled)
{
return m_pRAMBanks[(address - 0xA000) + m_CurrentRAMAddress];
}
else
{
Log("--> ** Attempting to read from disabled ram %X", address);
return 0xFF;
}
}
else
else if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
{
Log("--> ** Attempting to read from disabled ram %X", address);
return 0xFF;
switch (m_RTCRegister)
{
case 0x08:
return m_iRTCLatchedSeconds;
break;
case 0x09:
return m_iRTCLatchedMinutes;
break;
case 0x0A:
return m_iRTCLatchedHours;
break;
case 0x0B:
return m_iRTCLatchedDays;
break;
case 0x0C:
return m_iRTCLatchedControl;
break;
default:
return 0xFF;
}
}
}
else if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
{
switch (m_RTCRegister)
else
{
case 0x08:
return m_iRTCLatchedSeconds;
break;
case 0x09:
return m_iRTCLatchedMinutes;
break;
case 0x0A:
return m_iRTCLatchedHours;
break;
case 0x0B:
return m_iRTCLatchedDays;
break;
case 0x0C:
return m_iRTCLatchedControl;
break;
default:
return 0xFF;
Log("--> ** Attempting to read from disabled RTC %X", address);
return 0xFF;
}
}
else
default:
{
Log("--> ** Attempting to read from disabled RTC %X", address);
return 0xFF;
return m_pMemory->Retrieve(address);
}
}
else
return m_pMemory->Retrieve(address);
}

void MBC3MemoryRule::PerformWrite(u16 address, u8 value)
{
if (address < 0x2000)
{
if (m_pCartridge->GetRAMSize() > 0)
m_bRamEnabled = (value & 0x0F) == 0x0A;
m_bRTCEnabled = (value & 0x0F) == 0x0A;
}
else if (address >= 0x2000 && address < 0x4000)
switch (address & 0xE000)
{
m_iCurrentROMBank = value & 0x7F;
if (m_iCurrentROMBank == 0)
m_iCurrentROMBank = 1;
m_iCurrentROMBank &= (m_pCartridge->GetROMBankCount() - 1);
}
else if (address >= 0x4000 && address < 0x6000)
{
if ((value >= 0x08) && (value <= 0x0C))
case 0x0000:
{
// RTC
if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
{
m_RTCRegister = value;
m_iCurrentRAMBank = -1;
}
if (m_pCartridge->GetRAMSize() > 0)
m_bRamEnabled = (value & 0x0F) == 0x0A;
m_bRTCEnabled = (value & 0x0F) == 0x0A;
break;
}
else if (value <= 0x03)
case 0x2000:
{
if (m_bRamEnabled)
{
m_iCurrentRAMBank = value;
m_iCurrentRAMBank &= (m_pCartridge->GetRAMBankCount() - 1);
}
m_iCurrentROMBank = value & 0x7F;
if (m_iCurrentROMBank == 0)
m_iCurrentROMBank = 1;
m_iCurrentROMBank &= (m_pCartridge->GetROMBankCount() - 1);
m_CurrentROMAddress = m_iCurrentROMBank * 0x4000;
break;
}
}
else if (address >= 0x6000 && address < 0x8000)
{
if (m_pCartridge->IsRTCPresent())
case 0x4000:
{
// RTC Latch
if ((m_iRTCLatch == 0x00) && (value == 0x01))
if ((value >= 0x08) && (value <= 0x0C))
{
UpdateRTC();
m_iRTCLatchedSeconds = m_iRTCSeconds;
m_iRTCLatchedMinutes = m_iRTCMinutes;
m_iRTCLatchedHours = m_iRTCHours;
m_iRTCLatchedDays = m_iRTCDays;
m_iRTCLatchedControl = m_iRTCControl;
// RTC
if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
{
m_RTCRegister = value;
m_iCurrentRAMBank = -1;
}
}
if ((value == 0x00) || (value == 0x01))
else if (value <= 0x03)
{
m_iRTCLatch = value;
if (m_bRamEnabled)
{
m_iCurrentRAMBank = value;
m_iCurrentRAMBank &= (m_pCartridge->GetRAMBankCount() - 1);
m_CurrentRAMAddress = m_iCurrentRAMBank * 0x2000;
}
}
break;
}
}
else if (address >= 0xA000 && address < 0xC000)
{
if (m_iCurrentRAMBank >= 0)
case 0x6000:
{
if (m_bRamEnabled)
{
m_pRAMBanks[(address - 0xA000) + (0x2000 * m_iCurrentRAMBank)] = value;
}
else
if (m_pCartridge->IsRTCPresent())
{
Log("--> ** Attempting to write on RAM when ram is disabled %X %X", address, value);
// RTC Latch
if ((m_iRTCLatch == 0x00) && (value == 0x01))
{
UpdateRTC();
m_iRTCLatchedSeconds = m_iRTCSeconds;
m_iRTCLatchedMinutes = m_iRTCMinutes;
m_iRTCLatchedHours = m_iRTCHours;
m_iRTCLatchedDays = m_iRTCDays;
m_iRTCLatchedControl = m_iRTCControl;
}
if ((value == 0x00) || (value == 0x01))
{
m_iRTCLatch = value;
}
}
break;
}
else if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
case 0xA000:
{
m_RTCLastTime = m_pCartridge->GetCurrentRTC();
switch (m_RTCRegister)
if (m_iCurrentRAMBank >= 0)
{
if (m_bRamEnabled)
{
m_pRAMBanks[(address - 0xA000) + m_CurrentRAMAddress] = value;
}
else
{
Log("--> ** Attempting to write on RAM when ram is disabled %X %X", address, value);
}
}
else if (m_pCartridge->IsRTCPresent() && m_bRTCEnabled)
{
m_RTCLastTime = m_pCartridge->GetCurrentRTC();
switch (m_RTCRegister)
{
case 0x08:
m_iRTCSeconds = value;
break;
case 0x09:
m_iRTCMinutes = value;
break;
case 0x0A:
m_iRTCHours = value;
break;
case 0x0B:
m_iRTCDays = value;
break;
case 0x0C:
if (m_iRTCControl & 0x80)
m_iRTCControl = 0x80 | value;
else
m_iRTCControl = value;
break;
}
}
else
{
case 0x08:
m_iRTCSeconds = value;
break;
case 0x09:
m_iRTCMinutes = value;
break;
case 0x0A:
m_iRTCHours = value;
break;
case 0x0B:
m_iRTCDays = value;
break;
case 0x0C:
if (m_iRTCControl & 0x80)
m_iRTCControl = 0x80 | value;
else
m_iRTCControl = value;
break;
Log("--> ** Attempting to write on RTC when RTC is disabled %X %X", address, value);
}
break;
}
else
default:
{
Log("--> ** Attempting to write on RTC when RTC is disabled %X %X", address, value);
m_pMemory->Load(address, value);
break;
}
}
else
m_pMemory->Load(address, value);
}

void MBC3MemoryRule::Reset(bool bCGB)
Expand All @@ -217,9 +236,11 @@ void MBC3MemoryRule::Reset(bool bCGB)
m_RTCRegister = 0;
m_RTCLastTime = -1;
m_RTCLastTimeCache = 0;
m_CurrentROMAddress = 0x4000;
m_CurrentRAMAddress = 0;
}

void MBC3MemoryRule::SaveRam(std::ofstream &file)
void MBC3MemoryRule::SaveRam(std::ofstream & file)
{
Log("MBC3MemoryRule save RAM...");

Expand Down Expand Up @@ -248,7 +269,7 @@ void MBC3MemoryRule::SaveRam(std::ofstream &file)
Log("MBC3MemoryRule save RAM done");
}

void MBC3MemoryRule::LoadRam(std::ifstream &file)
void MBC3MemoryRule::LoadRam(std::ifstream & file)
{
Log("MBC3MemoryRule load RAM...");

Expand Down
2 changes: 2 additions & 0 deletions src/MBC3MemoryRule.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,8 @@ class MBC3MemoryRule : public MemoryRule
u8 m_RTCRegister;
time_t m_RTCLastTime;
time_t m_RTCLastTimeCache;
int m_CurrentROMAddress;
int m_CurrentRAMAddress;
};

#endif /* MBC3MEMORYRULE_H */
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