/*
* This file is part of the 65816 Emulator Library.
* Copyright (c) 2018 Francesco Rigoni.
*
* https://github.com/FrancescoRigoni/Lib65816
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#include "../Interrupt.hpp"
#include "../Cpu65816.hpp"
#define LOG_TAG "Cpu::executeInterrupt"
/**
* This file contains the implementation for all OpCodes
* that deal with interrupts.
*/
void Cpu65816::executeInterrupt(OpCode &opCode) {
switch (opCode.getCode()) {
case(0x00): // BRK
{
if (mCpuStatus.emulationFlag()) {
mStack.push16Bit(static_cast(mProgramAddress.getOffset() + 2));
mCpuStatus.setBreakFlag();
mStack.push8Bit(mCpuStatus.getRegisterValue());
mCpuStatus.setInterruptDisableFlag();
#ifdef EMU_65C02
mCpuStatus.clearDecimalFlag();
#endif
setProgramAddress(Address(0x00, mEmulationInterrupts->brkIrq));
addToCycles(7);
} else {
mStack.push8Bit(mProgramAddress.getBank());
mStack.push16Bit(static_cast(mProgramAddress.getOffset() + 2));
mStack.push8Bit(mCpuStatus.getRegisterValue());
mCpuStatus.setInterruptDisableFlag();
mCpuStatus.clearDecimalFlag();
Address newAddress(0x00, mNativeInterrupts->brk);
setProgramAddress(newAddress);
addToCycles(8);
}
break;
}
case(0x02): // COP
{
if (mCpuStatus.emulationFlag()) {
mStack.push16Bit(static_cast(mProgramAddress.getOffset() + 2));
mStack.push8Bit(mCpuStatus.getRegisterValue());
mCpuStatus.setInterruptDisableFlag();
setProgramAddress(Address(0x00, mEmulationInterrupts->coProcessorEnable));
addToCycles(7);
} else {
mStack.push8Bit(mProgramAddress.getBank());
mStack.push16Bit(static_cast(mProgramAddress.getOffset() + 2));
mStack.push8Bit(mCpuStatus.getRegisterValue());
mCpuStatus.setInterruptDisableFlag();
setProgramAddress(Address(0x00, mNativeInterrupts->coProcessorEnable));
addToCycles(8);
}
mCpuStatus.clearDecimalFlag();
break;
}
case(0x40): // RTI
{
// Note: The picture in the 65816 programming manual about this looks wrong.
// This implementation follows the text instead.
mCpuStatus.setRegisterValue(mStack.pull8Bit());
if (mCpuStatus.emulationFlag()) {
Address newProgramAddress(mProgramAddress.getBank(), mStack.pull16Bit());
mProgramAddress = newProgramAddress;
addToCycles(6);
} else {
uint16_t offset = mStack.pull16Bit();
uint8_t bank = mStack.pull8Bit();
Address newProgramAddress(bank, offset);
mProgramAddress = newProgramAddress;
addToCycles(7);
}
}
default: {
LOG_UNEXPECTED_OPCODE(opCode);
}
}
}