emulib.plugins.cpu

Interface CPU

All Superinterfaces:

Plugin

All Known Implementing Classes:

AbstractCPU

public interface CPU
extends Plugin

Interface that covers CPU common operations. This is the main interface that CPU plug-in has to implement.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	CPU.CPUListener The listener interface for receiving CPU events.
static class	CPU.RunState The run state of the CPU.

Method Summary

Modifier and Type	Method and Description
boolean	addCPUListener(CPU.CPUListener listener) Adds the specified CPU listener to receive CPU events from this CPU.
void	execute() Runs CPU emulation.
Disassembler	getDisassembler() Get disassembler object.
int	getInstructionPosition() Get actual instruction position (before its execution).
JPanel	getStatusPanel() Get CPU status panel.
boolean	isBreakpointSet(int memLocation) Determine if a breakpoint is set at a memory location.
boolean	isBreakpointSupported() Determine whether breakpoints are supported by CPU.
void	pause() Pauses the CPU emulation.
boolean	removeCPUListener(CPU.CPUListener listener) Removes the specified CPU listener so that it no longer receives CPU events from this CPU.
void	reset(int startAddress) Perform reset of the CPU with specific starting address.
void	setBreakpoint(int memLocation) Set a breakpoint at a memory location.
boolean	setInstructionPosition(int pos) Set new actual instruction position (that will be executed as next).
void	step() Perform one step of CPU emulation.
void	stop() Stops the CPU emulation.
void	unsetBreakpoint(int memLocation) Unset a breakpoint at a memory location.

Methods inherited from interface emulib.plugins.Plugin

destroy, getTitle, getVersion, initialize, isShowSettingsSupported, reset, showSettings

Method Detail

addCPUListener

boolean addCPUListener(CPU.CPUListener listener)

Adds the specified CPU listener to receive CPU events from this CPU. CPU events occur when CPU changes its state, or run state. CPU state events don't occur if CPU is running, only happens with run state changes. If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the CPU listener

Returns:

true if the listener was added, false otherwise

removeCPUListener

boolean removeCPUListener(CPU.CPUListener listener)

Removes the specified CPU listener so that it no longer receives CPU events from this CPU. CPU events occur when CPU changes its state, or run state. CPU state events don't occur if CPU is running, only happens with run state changes. If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the CPU listener to be removed

Returns:

true if the listener was removed, false otherwise

step

void step()

Perform one step of CPU emulation. It means that one instruction should be executed. CPU state changes to state "running", then it executes one instruction, and then it should return to state "breakpoint" or "stopped". Correct timing of executed instruction isn't so important.

execute

void execute()

Runs CPU emulation. Change state of CPU to "running" and start instruction fetch/decode/execute loop. The emuStudio creates separate thread for this purpose. While CPU is running, the emuStudio will not allow to call method step(). A good CPU should performs right timing for instructions here. Debug window should not be updated after each instruction execution, in order to the execution loop would be faster.

pause

void pause()

Pauses the CPU emulation. If a thread was used for CPU execution and is running, then it should be stopped (destroyed) but the CPU state has to be saved for future run. CPU changes it state to "breakpoint".

stop

void stop()

Stops the CPU emulation. If a thread was used for CPU execution and is running, then it should be stopped (destroyed) but the CPU state can be saved. CPU changes its state to "stopped" and main module should now forbid execution any of methods step(), pause(), execute() until user resets the CPU. Debug window in main module should be updated with saved CPU state.

getStatusPanel

JPanel getStatusPanel()

Get CPU status panel. Each CPU plugin must have a status panel that shows some important CPU status (e.g. registers, flags, run state, etc.) and allows to manage some settings (e.g. a runtime frequency, etc.). This panel is located on the right side in the "emulation" panel of the main module. CPU itself should take care about updating the panel when it is appropriate.

Returns:

CPU status panel

isBreakpointSupported

boolean isBreakpointSupported()

Determine whether breakpoints are supported by CPU.

Returns:

true if breakpoints are supported, false otherwise

setBreakpoint

void setBreakpoint(int memLocation)

Set a breakpoint at a memory location. Does nothing if breakpoints are not supported.

Parameters:

memLocation - memory location where the breakpoint will be set

See Also:

isBreakpointSupported()

unsetBreakpoint

void unsetBreakpoint(int memLocation)

Unset a breakpoint at a memory location. Does nothing if breakpoints are not supported.

Parameters:

memLocation - memory location from where the breakpoint will be unset

See Also:

isBreakpointSupported()

isBreakpointSet

boolean isBreakpointSet(int memLocation)

Determine if a breakpoint is set at a memory location.

Parameters:

memLocation - memory location, from where the breakpoint will be determined

Returns:

true if breakpoint is set in the location, false otherwise or if breakpoints are not supported.

See Also:

isBreakpointSupported()

reset

void reset(int startAddress)

Perform reset of the CPU with specific starting address. This is used when program starting address is known. Otherwise it is used standard Plugin.reset() method

Parameters:

startAddress - Starting address/memory position of the program counter

getInstructionPosition

int getInstructionPosition()

Get actual instruction position (before its execution). Can be said, that this method should return PC (program counter) register (if CPU has one).

Returns:

memory position (address) of next instruction

setInstructionPosition

boolean setInstructionPosition(int pos)

Set new actual instruction position (that will be executed as next). It can be said, that a parameter represents new value of PC (program counter), if CPU has one. Otherwise CPU should interpret the position in the right manner. This method is called by main module when user perform "jump to address" operation.

Parameters:

pos - new address of actual instruction

Returns:

true if operation was successful, false otherwise

getDisassembler

Disassembler getDisassembler()

Get disassembler object. EmuStudio uses this for creating debug table.

Returns:

disassembler object