PIC24F16KL402 Datasheet, PDF (105/260 Pages) Microchip Technology – Low-Power, Low-Cost, General Purpose 16-Bit Flash Microcontrollers with nanoWatt XLP Technology

PIC24F16KL402 FAMILY
10.0 POWER-SAVING FEATURES
Note:
This data sheet summarizes the features
of this group of PIC24F devices. It is not
intended to be a comprehensive
reference source. For more information
on Power-Saving Features, refer to the
“PIC24F Family Reference Manual”,
“Section 39. Power-Saving Features
with Deep Sleep” (DS39727).
The PIC24F16KL402 family of devices provides the
ability to manage power consumption by selectively
managing clocking to the CPU and the peripherals. In
general, a lower clock frequency and a reduction in the
number of circuits being clocked constitutes lower
consumed power. All PIC24F devices manage power
consumption using several strategies:
• Clock frequency
• Instruction-based Idle and Sleep modes
• Hardware-based periodic wake-up from Sleep
• Software Controlled Doze mode
• Selective peripheral control in software
Combinations of these methods can be used to
selectively tailor an application’s power consumption,
while still maintaining critical application features, such
as timing-sensitive communications.
10.1 Clock Frequency and Clock
Switching
PIC24F devices allow for a wide range of clock
frequencies to be selected under application control. If
the system clock configuration is not locked, users can
choose low-power or high-precision oscillators by simply
changing the NOSC bits. The process of changing a
system clock during operation, as well as limitations to
the process, are discussed in more detail in Section 9.0
“Oscillator Configuration”.
10.2 Instruction-Based Power-Saving
Modes
PIC24F devices have two special power-saving modes
that are entered through the execution of a special
PWRSAV instruction. Sleep mode stops clock operation
and halts all code execution; Idle mode halts the CPU
and code execution, but allows peripheral modules to
continue operation.
The assembly syntax of the PWRSAV instruction is
shown in Example 10-1.
Note:
SLEEP_MODE and IDLE_MODE are
constants, defined in the assembler
include file for the selected device.
Sleep and Idle modes can be exited as a result of an
enabled interrupt, WDT time-out or a device Reset.
When the device exits these modes, it is said to
“wake-up”.
EXAMPLE 10-1: PWRSAV INSTRUCTION SYNTAX
PWRSAV
PWRSAV
#SLEEP_MODE
#IDLE_MODE
; Put the device into SLEEP mode
; Put the device into IDLE mode
 2011 Microchip Technology Inc.
DS31037B-page 105