Microchip Technology Microstick for the 3V PIC24F K-series DM240013-1 DM240013-1 Data Sheet

Product codes
DM240013-1
Page of 278
 2008-2011 Microchip Technology Inc.
DS39927C-page 155
PIC24F16KA102 FAMILY
19.0
REAL-TIME CLOCK AND 
CALENDAR (RTCC) 
The RTCC provides the user with a Real-Time Clock
and Calendar (RTCC) function that can be calibrated.
Key features of the RTCC module are:
• Operates in Deep Sleep mode
• Selectable clock source
• Provides hours, minutes and seconds using 
24-hour format
• Visibility of one half second period
• Provides calendar – weekday, date, month and 
year
• Alarm-configurable for half a second, one second, 
10 seconds, one minute, 10 minutes, one hour, 
one day, one week, one month or one year
• Alarm repeat with decrementing counter
• Alarm with indefinite repeat chime
• Year 2000 to 2099 leap year correction
• BCD format for smaller software overhead
• Optimized for long-term battery operation
• User calibration of the 32.768 kHz clock 
crystal/32K INTRC frequency with periodic 
auto-adjust
19.1
RTCC Source Clock
The user can select between the SOSC crystal
oscillator or the LPRC internal oscillator as the clock
reference for the RTCC module. This is configured
using the RTCOSC (FDS<5>) Configuration bit. This
gives the user an option to trade off system cost,
accuracy and power consumption, based on the overall
system needs.
The RTCC will continue to run, along with its chosen
clock source, while the device is held in Reset with
MCLR and will continue running after MCLR is
released.
FIGURE 19-1:
RTCC BLOCK DIAGRAM
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 the
Real-Time Clock and Calendar, refer to the
“PIC24F Family Reference Manual”
,
Section 29. “Real-Time Clock and
Calendar (RTCC)”
 (DS39696).
RTCC Clock Domain
CPU Clock Domain
RTCC
RTCC Prescalers
RTCC Timer
Comparator
Alarm Registers with Masks
Repeat Counter
0.5 Sec
RTCC Interrupt Logic
ALRMVAL
RTCVAL
ALCFGRPT
RCFGCAL
Alarm 
Event
YEAR
MTHDY
WKDYHR
MINSEC
ALMTHDY
ALWDHR
ALMINSEC
RTCC 
Interrupt
RTSECSEL<1:0>
RTCOE
10
00
01
Clock Source
1s
Pin
Alarm Pulse
Input from
SOSC/LPRC
Oscillator