public boolean tick(long simTime) {
if (stopNextInstruction) {
stopNextInstruction = false;
throw new RuntimeException("MSPSim requested simulation stop");
}
/* Nodes may be added in an ongoing simulation:
* Update cycle drift to current simulation time */
if (firstTick) {
firstTick = false;
cycleDrift += (-NR_CYCLES_PER_MSEC * simTime);
}
long maxSimTimeCycles = NR_CYCLES_PER_MSEC * (simTime + 1) + cycleDrift;
if (maxSimTimeCycles <= cycleCounter) {
return false;
}
// Leave control to emulated CPU
cycleCounter += 1;
MSP430 cpu = getCPU();
if (cpu.cycles > cycleCounter) {
/* CPU already ticked too far - just wait it out */
return true;
}
myMoteInterfaceHandler.doActiveActionsBeforeTick();
/* Experimental program counter history */
for (int i = pcHistory.length - 1; i > 0; i--) {
pcHistory[i] = pcHistory[i - 1];
}
pcHistory[0] = cpu.reg[MSP430.PC];
try {
cpu.step(cycleCounter);
} catch (EmulationException e) {
if (e.getMessage().startsWith("Bad operation")) {
/* Experimental: print program counter history */
LineListener oldListener = commandListener;
LineListener tmpListener =
new LineListener() {
public void lineRead(String line) {
logger.fatal(line);
}
};
setCLIListener(tmpListener);
logger.fatal("Bad operation detected. Program counter history:");
for (int element : pcHistory) {
sendCLICommand("line " + element);
}
setCLIListener(oldListener);
}
throw (RuntimeException)
new RuntimeException("Emulated exception: " + e.getMessage()).initCause(e);
}
/* Check if radio has pending incoming bytes */
if (myRadio != null && myRadio.hasPendingBytes()) {
myRadio.tryDeliverNextByte(cpu.cycles);
}
if (monitorStackUsage) {
int newStack = cpu.reg[MSP430.SP];
if (newStack < stackPointerLow && newStack > 0) {
stackPointerLow = cpu.reg[MSP430.SP];
// Check if stack is writing in memory
if (stackPointerLow < heapStartAddress) {
stackOverflowObservable.signalStackOverflow();
stopNextInstruction = true;
getSimulation().stopSimulation();
}
}
}
return true;
}
