PIC24FJ16MC101_12 Datasheet, PDF (219/350 Pages) Microchip Technology – 16-bit Microcontrollers (up to 32 KB Flash and 2 KB SRAM)

PIC24FJ16MC101/102 AND PIC24FJ32MC101/102/104
21.0 REAL-TIME CLOCK AND
CALENDAR (RTCC)
Note 1: This data sheet summarizes the features
of the PIC24FJ16MC101/102 and
PIC24FJ32MC101/102/104 family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 29. “Real-Time
Clock and Calendar (RTCC)”
(DS39696) in the “PIC24F Family
Reference Manual”, which is available on
the
Microchip
web
site
(www.microchip.com).
2: It is important to note that the
specifications in Section 26.0 “Electri-
cal Characteristics” of this data sheet,
supercede any specifications that may be
provided in PIC24F Family Reference
Manual sections.
3: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
FIGURE 21-1:
RTCC BLOCK DIAGRAM
RTCC Clock Domain
32.768 kHz Input
from SOSC Oscillator
RTCC Prescalers
0.5s
Alarm
Event
RTCC Timer
Comparator
Compare Registers
with Masks
Repeat Counter
This chapter discusses the Real-Time Clock and
Calendar (RTCC) module, which is available on
PIC24FJ16MC101/102
and
PIC24FJ32MC101/102/104 devices, and its operation.
Some of the key features of the RTCC module are:
• Time: hours, minutes, and seconds
• 24-hour format (military time)
• Calendar: weekday, date, month and year
• Alarm configurable
• Year range: 2000 to 2099
• Leap year correction
• BCD format for compact firmware
• Optimized for low-power operation
• User calibration with auto-adjust
• Calibration range: ±2.64 seconds error per month
• Requirements: External 32.768 kHz clock crystal
• Alarm pulse or seconds clock output on RTCC pin
The RTCC module is intended for applications where
accurate time must be maintained for extended periods
of time with minimum to no intervention from the CPU.
The RTCC module is optimized for low-power usage to
provide extended battery lifetime while keeping track of
time.
The RTCC module is a 100-year clock and calendar
with automatic leap year detection. The range of the
CPU Clock Domain
RCFGCAL
ALCFGRPT
RTCVAL
ALRMVAL
RTCC Interrupt Logic
RTCC Interrupt
Alarm Pulse
RTCOE
RTCC Pin
© 2011-2012 Microchip Technology Inc.
Preliminary
DS39997C-page 219