Simulate Interrupts and Clock Inputs
µVision3 simulates the behavior of the I/O inputs. If an I/O pin is configured as counter input the count value increments when the pin toggles. The following example shows how to simulate input for Counter 3:
// in your C user program
T3CON = 0x004B; // set T3 Counter Mode
You may toggle the counter input P3.6 with the VTREG PORT3, i.e. with a signal function:
signal void ToggleT3Input (void) {
while (1) { PORT3 = PORT3 ^ 0x0040; // toggle P3.6
twatch (CLOCK / 100000); // with 100kHz
}
}

View the Counter 3 status with the Peripheral dialog.
Also interrupt inputs are simulated: if a port pin is used as interrupt input, the interrupt request will be set if you toggle the associated I/O pin.