stops execution of a program and puts the PIC to sleep until reset or watchdog timeout.
The assembly language sleep instruction does for a PIC what the End instruction does for the BASIC Stamp; it shuts down the clock oscillator, halting program execution and reducing current draw to a few microamperes. If the PIC's watchdog timer is disabled (by a wdt_off switch in the device directive), that's it until the PIC is reset.
However, if the watchdog timer is on, the PIC will reawaken at the next timeout. If you want a watchdog-protected PIC to stay asleep, you must include code that checks the timeout and power-down bits (to and pd) for 00 and immediately puts the PIC back to sleep. See the section on the Sleep instruction for more information.