The PIC24FJ128GA310 family of devices introduces a greatly-expanded range of power-saving operating modes for the ultimate in power conservation. The new modes include： ? Retention Sleep， with essential circuits being powered from a separate low-voltage regulator ? Deep Sleep without RTCC， for the lowest possible power consumption under software control ? VBAT mode （with or without RTCC）， to continue operation limited operation from a back-up battery when VDD is removed Many of these new low-power modes also support the continuous operation of the low-power， on-chip Real-Time Clock/Calendar （RTCC）， making it possible for an application to keep time while the device is otherwise asleep. Aside from these new features， PIC24FJ128GA310 family devices also include all of the legacy power-saving features of previous PIC24F microcontrollers， such as： ? On-the-Fly Clock Switching， allowing the selection of a lower-power clock during run time ? Doze Mode Operation， for maintaining peripheral clock speed while slowing the CPU clock ? Instruction-Based Power-Saving Modes， for quick invocation of Idle and the many Sleep modes.