avrora.sim
Class Simulator

java.lang.Object
  avrora.sim.Simulator

All Implemented Interfaces:

IORegisterConstants

Direct Known Subclasses:

ATMega128L.SimImpl

public abstract class Simulator

extends java.lang.Object

implements IORegisterConstants

The Simulator class implements a full processor simulator for the AVR instruction set. It is the base class of specific implementations that implement processor-specific behavior.

See Also:

Program, Instr, BaseInterpreter

Nested Class Summary

static class	Simulator.BreakPointException The BreakPointException is an exception that is thrown by the simulator before it executes an instruction which has a breakpoint.
class	Simulator.ClockCycleTimeout The InstructionCountTimeout class is a probe that simply counts down and throws an exception when the count reaches zero.
static interface	Simulator.Event The Simulator.Event interface represents an event that is fired when a timed event occurs within the simulator.
class	Simulator.FlagRegister
static class	Simulator.InstructionCountTimeout The InstructionCountTimeout class is a probe that simply counts down and throws a TimeoutException when the count reaches zero.
static interface	Simulator.Interrupt The Interrupt interface represents the behavior of an interrupt (how it manipulates the state of the processor) when it is posted and when it is triggered (handler is executed by the processor).
class	Simulator.MaskableInterrupt
class	Simulator.MaskRegister
static interface	Simulator.Probe The Simulator.Probe interface represents a programmer-defined probe that can be inserted at a particular instruction in the program. or at every instruction.
static class	Simulator.TimeoutException The TimeoutException is thrown by the simulator when a timeout reaches zero.
class	Simulator.UnorderedFlagRegister Flag register for flag register that corresponds to a group of interrupts that do not necessarily have a clean, linear mapping to bits on the register.
class	Simulator.UnorderedMaskRegister Mask register associated with an UnorderedFlagregister.
static interface	Simulator.Watch The MemoryProbe interface represents a user probe that is fired when a watchpoint detects an access to an address where this memory probe has been inserted.

Field Summary

protected DeltaQueue	eventQueue The eventQueue field stores a reference to the event queue, a delta list of all events to be processed in order.
static Simulator.Interrupt	IGNORE The IGNORE field stores a reference to a singleton anonymous class that ignores posting and firing of an interrupt.
protected BaseInterpreter	interpreter The interpreter field stores a reference to the instruction set interpreter.
protected Simulator.Interrupt[]	interrupts The interrupts array stores a reference to an Interrupt instance for each of the interrupt vectors supported in the simulator.
static boolean	LEGACY_INTERPRETER The LEGACY_INTERPRETER field is used to turn on and off the legacy interpreter.
static int	MAX_INTERRUPTS The MAX_INTERRUPTS fields stores the maximum number of interrupt vectors supported by the simulator.
protected Microcontroller	microcontroller The microcontroller field stores a reference to the microcontroller being simulated.
protected Program	program The program field allows descendants of the Simulator class to access the program that is currently loaded in the simulator.
static Simulator.Probe	TRACEPROBE The TRACEPROBE field represents a simple probe that prints an instruction to the terminal as it is encountered.

Fields inherited from interface avrora.sim.IORegisterConstants

ACSR, ADCH, ADCL, ADCSRA, ADMUX, ASSR, DDRA, DDRB, DDRC, DDRD, DDRE, DDRF, DDRG, EEARH, EEARL, EECR, EEDR, EICRA, EICRB, EIFR, EIMSK, ETIFR, ETIMSK, ICR1H, ICR1L, ICR3H, ICR3L, MCUCR, MCUCSR, NUM_REGS, OCDR, OCR0, OCR1AH, OCR1AL, OCR1BH, OCR1BL, OCR1CH, OCR1CL, OCR2, OCR3AH, OCR3AL, OCR3BH, OCR3BL, OCR3CH, OCR3CL, OSCCAL, PINA, PINB, PINC, PIND, PINE, PINF, PING, PORTA, PORTB, PORTC, PORTD, PORTE, PORTF, PORTG, RAMPZ, SFIOR, SPCR, SPDR, SPH, SPL, SPMCSR, SPSR, SREG, SREG_C, SREG_H, SREG_I, SREG_N, SREG_S, SREG_T, SREG_V, SREG_Z, TCCR0, TCCR1A, TCCR1B, TCCR1C, TCCR2, TCCR3A, TCCR3B, TCCR3C, TCNT0, TCNT1H, TCNT1L, TCNT2, TCNT3H, TCNT3L, TIFR, TIMSK, TWAR, TWBR, TWCR, TWDR, TWSR, UBRR0H, UBRR0L, UBRR1H, UBRR1L, UCSR0A, UCSR0B, UCSR0C, UCSR1A, UCSR1B, UCSR1C, UDR0, UDR1, WDTCR, XDIV, XMCRA, XMCRB

Constructor Summary

Simulator(Microcontroller mcu, Program p)
The constructor creates the internal data structures and initial state of the processor.

Method Summary

void	delay(long cycles) The delay() method introduces a delay in the execution of the instructions of the program.
void	forceInterrupt(int num) The forceInterrupt() method forces the simulator to post the specified interrupt regardless of the normal source of the interrupt.
protected int	getInterruptVectorAddress(int inum) The getInterruptVectorAddress() method computes the location in memory to jump to for the given interrupt number.
Microcontroller	getMicrocontroller() The getMicrocontroller() method gets a reference to the microcontroller being simulated.
Program	getProgram()
State	getState() The getState() retrieves a reference to the current state of the simulation, including the values of all registers, the SRAM, the IO register, the program memory, program counter, etc.
void	insertBreakPoint(int addr) The insertBreakPoint() method inserts a breakpoint at the instruction at the specified address.
void	insertEvent(Simulator.Event e, long cycles) The insertEvent() method inserts an event into the event queue of the simulator with the specified delay in clock cycles.
PeriodicEvent	insertPeriodicEvent(Simulator.Event e, long period) The insertPeriodicEvent() method inserts an event into the event queue of the simulator with the specified period.
void	insertProbe(Simulator.Probe p) The insertProbe() method allows a probe to be inserted that is executed before and after every instruction that is executed by the simulator
void	insertProbe(Simulator.Probe p, int addr) The insertProbe() method allows a probe to be inserted at a particular address in the program that corresponds to an instruction.
void	insertTimeout(long cycles) The insertTimeout() method inserts an event into the event queue of the simulator that causes it to stop execution and throw a Simulator.TimeoutException when the specified number of clock cycles have expired.
void	insertWatch(Simulator.Watch p, int data_addr) The insertWatch() method allows a watch to be inserted at a memory location.
void	removeBreakPoint(int addr) The removeBreakPoint method removes all breakpoints at the specified instruction at the specified address.
void	removeEvent(Simulator.Event e) The removeEvent() method removes an event from the event queue of the simulator.
void	removeProbe(Simulator.Probe b) The removeProbe() method removes a probe from the global probe table (the probes executed before and after every instruction).
void	removeProbe(Simulator.Probe p, int addr) The removeProbe() method removes a probe from the instruction at the specified the address.
void	removeWatch(Simulator.Watch p, int data_addr) The removeWatch() method removes a given watch from the memory location.
void	reset() The reset() method stops the simulation and resets its state to the default initial state.
void	start() The start() method begins the simulation.
void	stop() The stop() method stops the simulation if it is running.
protected void	triggerInterrupt(int num) The triggerInterrupt() method is used by device implementations when they detect that an interrupt should be triggered.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TRACEPROBE

public static final Simulator.Probe TRACEPROBE

The TRACEPROBE field represents a simple probe that prints an instruction to the terminal as it is encountered. This is useful for tracing program execution over simulation.

program

protected final Program program

The program field allows descendants of the Simulator class to access the program that is currently loaded in the simulator.

microcontroller

protected final Microcontroller microcontroller

The microcontroller field stores a reference to the microcontroller being simulated.

LEGACY_INTERPRETER

public static boolean LEGACY_INTERPRETER

The LEGACY_INTERPRETER field is used to turn on and off the legacy interpreter. By default, the legacy interpreter is used.

interpreter

protected BaseInterpreter interpreter

The interpreter field stores a reference to the instruction set interpreter.

interrupts

protected Simulator.Interrupt[] interrupts

The interrupts array stores a reference to an Interrupt instance for each of the interrupt vectors supported in the simulator.

eventQueue

protected DeltaQueue eventQueue

The eventQueue field stores a reference to the event queue, a delta list of all events to be processed in order.

MAX_INTERRUPTS

public static int MAX_INTERRUPTS

The MAX_INTERRUPTS fields stores the maximum number of interrupt vectors supported by the simulator.

IGNORE

public static final Simulator.Interrupt IGNORE

The IGNORE field stores a reference to a singleton anonymous class that ignores posting and firing of an interrupt. This is the default value for interrupts in a freshly initialized Simulator instance.

Constructor Detail

Simulator

public Simulator(Microcontroller mcu,
                 Program p)

The constructor creates the internal data structures and initial state of the processor. It constructs an instance of the simulator that is ready to have devices attached, IO registers probed, and probes and events inserted. Users should not create Simulator instances directly, but instead should get an instance of the appropriate processor and load the program into it.

Parameters:

p - the program to load into the simulator

Method Detail

getMicrocontroller

public Microcontroller getMicrocontroller()

The getMicrocontroller() method gets a reference to the microcontroller being simulated.

Returns:

a reference to the microcontroller being simulated

getProgram

public Program getProgram()

getState

public State getState()

The getState() retrieves a reference to the current state of the simulation, including the values of all registers, the SRAM, the IO register, the program memory, program counter, etc. This state is mutable.

Returns:

a reference to the current state of the simulation

start

public void start()

The start() method begins the simulation. It causes the simulator to enter a runLoop that executes instructions, firing probes and events as it executes. The start() method returns normally when the break AVR instruction is executed, when a BreakPointException is thrown, when a TimeoutException is thrown, or when the stop() method on this simulator instance is called.

stop

public void stop()

The stop() method stops the simulation if it is running. This method can be called from within a probe or event or from another thread.

reset

public void reset()

The reset() method stops the simulation and resets its state to the default initial state. Probes inserted in the program are retained. All events are removed.

getInterruptVectorAddress

protected int getInterruptVectorAddress(int inum)

The getInterruptVectorAddress() method computes the location in memory to jump to for the given interrupt number. On the Atmega128L, the starting point is the beginning of memory and each interrupt vector slot is 4 bytes. On older architectures, this is not the case, therefore this method has to be implemented according to the specific device being simulated.

Parameters:

inum - the interrupt number

Returns:

the byte address that represents the address in the program to jump to when this interrupt is fired

insertProbe

public void insertProbe(Simulator.Probe p)

The insertProbe() method allows a probe to be inserted that is executed before and after every instruction that is executed by the simulator

Parameters:

p - the probe to insert

insertProbe

public void insertProbe(Simulator.Probe p,
                        int addr)

The insertProbe() method allows a probe to be inserted at a particular address in the program that corresponds to an instruction. The probe is then fired before and after that particular instruction is executed.

Parameters:

p - the probe to insert

addr - the address at which to insert the probe

removeProbe

public void removeProbe(Simulator.Probe b)

The removeProbe() method removes a probe from the global probe table (the probes executed before and after every instruction). The comparison used is reference equality, not .equals().

Parameters:

b - the probe to remove

removeProbe

public void removeProbe(Simulator.Probe p,
                        int addr)

The removeProbe() method removes a probe from the instruction at the specified the address. The comparison used is reference equality, not .equals().

Parameters:

p - the probe to remove

addr - the address from which to remove the probe

insertBreakPoint

public void insertBreakPoint(int addr)

The insertBreakPoint() method inserts a breakpoint at the instruction at the specified address. At most one breakpoint can be inserted at a particular instruction. Subsequent calls to this method would then have no effect for the same address.

Parameters:

addr -

removeBreakPoint

public void removeBreakPoint(int addr)

The removeBreakPoint method removes all breakpoints at the specified instruction at the specified address.

Parameters:

addr -

insertWatch

public void insertWatch(Simulator.Watch p,
                        int data_addr)

The insertWatch() method allows a watch to be inserted at a memory location. The probe will be executed before every read or write to that memory location.

Parameters:

p - the probe to insert

data_addr - the data address at which to insert the probe

removeWatch

public void removeWatch(Simulator.Watch p,
                        int data_addr)

The removeWatch() method removes a given watch from the memory location. Reference equality is used to check for equality when removing probes, not .equals().

Parameters:

p - the probe to remove

data_addr - the data address from which to remove the probe

forceInterrupt

public void forceInterrupt(int num)

The forceInterrupt() method forces the simulator to post the specified interrupt regardless of the normal source of the interrupt. If there is a flag register associated with the specified interrupt, then the flag register's value will be set as if the original source of the interrupt (e.g. a timer) had posted the interrupt. As with a normal post of the interrupt, if the interrupt is masked out via a mask register or the master interrupt enable bit, the interrupt will not be delivered. The main reason that this interface exists is for forcing programs to handle interrupts and observe their behavior.

Parameters:

num - the interrupt number to force

triggerInterrupt

protected void triggerInterrupt(int num)

The triggerInterrupt() method is used by device implementations when they detect that an interrupt should be triggered. This method will check whether this interrupt is enabled by consulting its own internal table of interrupts that is kept consistent during writes to IO registers.

Parameters:

num - the number of the interrupt to trigger

insertEvent

public void insertEvent(Simulator.Event e,
                        long cycles)

The insertEvent() method inserts an event into the event queue of the simulator with the specified delay in clock cycles. The event will then be executed at the future time specified

Parameters:

e - the event to be inserted

cycles - the number of cycles in the future at which to fire

insertTimeout

public void insertTimeout(long cycles)

The insertTimeout() method inserts an event into the event queue of the simulator that causes it to stop execution and throw a Simulator.TimeoutException when the specified number of clock cycles have expired.

Parameters:

cycles - the number of cycles to run before timing out

insertPeriodicEvent

public PeriodicEvent insertPeriodicEvent(Simulator.Event e,
                                         long period)

The insertPeriodicEvent() method inserts an event into the event queue of the simulator with the specified period. The PeriodicEvent instance created will continually reinsert the event after each firing to achieve predictable periodic behavior.

Parameters:

e - the event to insert

period - the period in clock cycles

Returns:

the PeriodicEvent instance inserted

removeEvent

public void removeEvent(Simulator.Event e)

The removeEvent() method removes an event from the event queue of the simulator. The comparison used is reference equality, not .equals().

Parameters:

e - the event to remove

delay

public void delay(long cycles)

The delay() method introduces a delay in the execution of the instructions of the program. This is used by some devices for correct timing behavior. For example, the EEPROM, when written, causes a small delay in which no instructions are executed.

Parameters:

cycles - the number of cycles to delay the simulation