/**
* Used to stop CPU execution and enable single stepping through opcodes via the interactive
* debugger (only when Debug = true).
*/
public void Break()
{
if (!Debug)
{
return;
}
_singleStepping = true;
if (OnBreakpointHitEvent != null)
{
_isWaitingForInteractiveDebugger = true;
OnBreakpointHitEvent.Invoke();
}
}
/**
* Used to reverse step backwards a single step, effectively reverting the CPU to the state
* prior to the last opcode executing. This requires Debug=true and ReverseStepEnabled=true.
*/
public void ReverseStep()
{
if (!Debug && !ReverseStepEnabled)
{
throw new Exception("Debug feature: reverse stepping is not enabled.");
}
var state = _executionHistory[_executionHistory.Count - 1];
_executionHistory.RemoveAt(_executionHistory.Count - 1);
// The first time we step backwards in the debugger, the most recent saved execution state
// will be the same as the current state. In that case, pop again to get the last state.
if (state.Registers.PC == _cpu.Registers.PC && _executionHistory.Count > 0)
{
state = _executionHistory[_executionHistory.Count - 1];
_executionHistory.RemoveAt(_executionHistory.Count - 1);
}
LoadState(state);
_cyclesSinceLastInterrupt -= state.LastCyclesExecuted.Value;
OnBreakpointHitEvent.Invoke();
}
