/// <summary>
/// Executes one instruction and returns.
/// </summary>
public void RunOneInstruction()
{
try {
ushort word = ReadMemInt16(PC, SegmentIndex.CS);
PC += 2;
// Check for hardware interrupt:
if (PS_H && !PS_Q && BUS.IsIRQ)
{
Interrupt_HWI();
}
// Check for RTC interrupt:
if (m_RTC.IsEnabled && m_RTC.IRQ(Cycles))
{
Interrupt_Clock();
}
// Execute Memory[PC]
YCPUInstruction opcode = m_Opcodes[word & 0x00FF];
opcode.Opcode(word);
// Increment the Cycle counter.
Cycles += opcode.Cycles;
}
catch (SegFaultException e) {
Interrupt_SegFault(e.SegmentType, 0xffff, PC);
}
}
/// <summary>
/// Executes a set number of cycles, or infinite cycles.
/// </summary>
/// <param name="cyclecount">How many cycles to run before stopping. Default value of -1 will run until Pause() is called.</param>
public void Run(int cyclecount = -1)
{
// Count Cycles:
long cyclesTarget = cyclecount == -1 ? long.MaxValue : cyclecount + Cycles;
// Run the processor for cyclecount Cycles:
Running = true;
while (Running)
{
try {
ushort word = ReadMemInt16(PC, SegmentIndex.CS);
PC += 2;
// Execute Memory[PC] and increment the cycle counter:
YCPUInstruction opcode = m_Opcodes[word & 0x00FF];
opcode.Opcode(word);
Cycles += opcode.Cycles;
// Check for hardware interrupt:
if (PS_H && !PS_Q && BUS.IsIRQ)
{
Interrupt_HWI();
}
// Check for RTC interrupt:
if (m_RTC.IsEnabled && m_RTC.IRQ(Cycles))
{
Interrupt_Clock();
}
// Check to see if we've exceeded our cycle target:
if (Cycles >= cyclesTarget)
{
m_Pausing = true;
}
if (m_Pausing)
{
Running = false;
m_Pausing = false;
}
}
catch (SegFaultException e) {
Interrupt_SegFault(e.SegmentType, 0xffff, PC);
}
}
}