// global system clock
public void Clock()
{
ppu.Clock();
if (clockCounter % 3 == 0)
{
if (dmaStarted)
{
if (dmaDummy)
{
if (clockCounter % 2 == 1)
{
dmaDummy = false;
}
}
else
{
if (clockCounter % 2 == 0)
{
UInt16 address = BitMagic.Combine(dmaPage, dmaAddress);
dmaData = CpuRead(address);
}
else
{
ppu.Oam[dmaAddress++] = dmaData;
// after 256 writes dmaAddress loops back to zero
if (dmaAddress == 0)
{
dmaStarted = false;
dmaDummy = true;
}
}
}
}
else
{
cpu.Clock();
}
}
if (ppu.EmitNmi)
{
cpu.NMI();
}
clockCounter++;
}
private void Verify(IEnumerable <AccessEntry> accesses)
{
Cpu.ForceOpcodeSync();
foreach (var access in accesses)
{
System.Invocations.Clear();
var address = access.Address;
Cpu.Clock();
switch (access.AccessType)
{
case AccessType.Read:
if (address >= 0)
{
Console.WriteLine("Verifying READ at ${0:x4}", address);
System.Verify(m => m.Read(It.IsIn(address)), Times.Once);
System.Verify(m => m.Read(It.IsNotIn(address)), Times.Never);
}
else
{
Console.WriteLine("Verifying READ at any address");
System.Verify(m => m.Read(It.IsAny <int>()), Times.Once);
}
System.Verify(m => m.Write(It.IsAny <int>(), It.IsAny <int>()), Times.Never);
break;
case AccessType.Write:
if (address >= 0)
{
Console.WriteLine("Verifying WRITE at ${0:x4}", address);
System.Verify(m => m.Write(It.IsIn(address), It.IsAny <int>()), Times.Once);
System.Verify(m => m.Write(It.IsNotIn(address), It.IsAny <int>()), Times.Never);
}
else
{
Console.WriteLine("Verifying WRITE at any address");
System.Verify(m => m.Write(It.IsAny <int>(), It.IsAny <int>()), Times.Once);
}
System.Verify(m => m.Read(It.IsAny <int>()), Times.Never);
break;
}
}
Cpu.Sync.Should().BeTrue("Sync must occur after opcode finishes.");
}
static void Run(byte[] program)
{
Rom programMemory = new Rom(program);
DataBus mainBus = new DataBus(0xFFFF);
mainBus.ConnectDevice(programMemory, (uint)(0xFFFF - program.Length), 0xFFFF);
Cpu cpu = new Cpu(mainBus);
cpu.Reset();
stepMode = StepMode.RUN;
ProcessInput();
while (true)
{
bool isDoStep = doStep;
if (stepMode == StepMode.RUN || doStep)
{
cpu.Clock();
}
//if (cpu.RemainingInstructionCycles == 0)
//{
if (stepMode == StepMode.RUN || doStep)
{
Console.WriteLine("A: ${0:X2} | X: ${1:X2} | Y: ${2:X2}", cpu.A, cpu.X, cpu.Y);
Console.WriteLine("PC: ${0:X4}", cpu.ProgramCounter);
Console.WriteLine("Next: {0}", InstructionSet.InstuctionsByOpcode[programMemory.ReadByte(cpu.ProgramCounter)].Name);
}
if (stepMode == StepMode.STEP && isDoStep == doStep)
{
doStep = false;
}
//}
}
}
public void CpuCanRunOneCycle()
{
Cpu.Clock();
}