PIC24FJ128GC010 Datasheet, PDF (175/472 Pages) Microchip Technology – 16-Bit Flash Microcontrollers with 12-Bit Pipeline A/D, Sigma-Delta A/D, USB On-The-Go and XLP Technology

PIC24FJ128GC010 FAMILY
Any time the DSEN bit is set, all bits in the DSWAKE
register will be automatically cleared.
EXAMPLE 10-2: THE REPEAT SEQUENCE
Example 1:
mov #8000, w2 ; enable DS
mov w2, DSCON
mov w2, DSCON ; second write required to
actually write to DSCON
Example 2:
bset
nop
nop
nop
bset
DSCON, #15
DSCON, #15
; enable DS (two writes required)
10.4.3 EXITING DEEP SLEEP MODES
Deep Sleep modes exit on any one of the following events:
• POR event on VDD supply. If there is no DSBOR
circuit to re-arm the VDD supply POR circuit, the
external VDD supply must be lowered to the
natural arming voltage of the POR circuit.
• DSWDT time-out. When the DSWDT timer times
out, the device exits Deep Sleep.
• RTCC alarm (if RTCEN = 1).
• Assertion (‘0’) of the MCLR pin.
• Assertion of the INT0 pin (if the interrupt was
enabled before Deep Sleep mode was entered).
The polarity configuration is used to determine the
assertion level (‘0’ or ‘1’) of the pin that will cause
an exit from Deep Sleep mode. Exiting from Deep
Sleep mode requires a change on the INT0 pin
while in Deep Sleep mode.
Note: Any interrupt pending when entering
Deep Sleep mode is cleared.
Exiting Deep Sleep generally does not retain the state
of the device and is equivalent to a Power-on Reset
(POR) of the device. Exceptions to this include the
RTCC (if present), which remains operational through
the wake-up, the DSGPRx registers and DSWDT.
Wake-up events that occur from the time Deep Sleep
exits, until the time the POR sequence completes, are
not ignored. The DSWAKE register will capture ALL
wake-up events, from setting DSEN to clearing
RELEASE.
The sequence for exiting Deep Sleep mode is:
1. After a wake-up event, the device exits Deep
Sleep and performs a POR. The DSEN bit is
cleared automatically. Code execution resumes
at the Reset vector.
2. To determine if the device exited Deep Sleep,
read the Deep Sleep bit, DPSLP (RCON<10>).
This bit will be set if there was an exit from Deep
Sleep mode. If the bit is set, clear it.
3. Determine the wake-up source by reading the
DSWAKE register.
4. Determine if a DSBOR event occurred during
Deep Sleep mode by reading the DSBOR bit
(DSCON<1>).
5. If application context data has been saved, read
it back from the DSGPR0 and DSGPR1 registers.
6. Clear the RELEASE bit (DSCON<0>).
10.4.4
SAVING CONTEXT DATA WITH THE
DSGPRx REGISTERS
As exiting Deep Sleep mode causes a POR, most
Special Function Registers reset to their default POR
values. In addition, because VCORE power is not sup-
plied in Deep Sleep mode, information in data RAM
may be lost when exiting this mode.
Applications which require critical data to be saved,
prior to Deep Sleep, may use the Deep Sleep General
Purpose registers, DSGPR0 and DSGPR1, or data
EEPROM (if available). Unlike other SFRs, the con-
tents of these registers are preserved while the device
is in Deep Sleep mode. After exiting Deep Sleep,
software can restore the data by reading the registers
and clearing the RELEASE bit (DSCON<0>).
10.4.5 I/O PINS IN DEEP SLEEP MODES
During Deep Sleep, the general purpose I/O pins retain
their previous states and the Secondary Oscillator
(SOSC) will remain running, if enabled. Pins that are
configured as inputs (TRISx bit set), prior to entry into
Deep Sleep, remain high-impedance during Deep
Sleep. Pins that are configured as outputs (TRISx bit
clear), prior to entry into Deep Sleep, remain as output
pins during Deep Sleep. While in this mode, they
continue to drive the output level determined by their
corresponding LATx bit at the time of entry into Deep
Sleep.
 2012-2013 Microchip Technology Inc.
DS30009312B-page 175