PIC32MX1XX_12 Datasheet, PDF (191/328 Pages) Microchip Technology – 32-bit Microcontrollers (up to 128 KB Flash and 32 KB SRAM) with Audio and Graphics Interfaces, USB, and Advanced Analog

PIC32MX1XX/2XX
20.0 REAL-TIME CLOCK AND
CALENDAR (RTCC)
Note 1: This data sheet summarizes the features
of the PIC32MX1XX/2XX 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)”
(DS61125) in the “PIC32 Family
Reference Manual”, which is available
from the Microchip web site
(www.microchip.com/PIC32).
2: 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.
The PIC32 RTCC module is intended for applications in
which accurate time must be maintained for extended
periods of time with minimal or no CPU intervention.
Low-power optimization provides extended battery
lifetime while keeping track of time.
FIGURE 20-1:
RTCC BLOCK DIAGRAM
Following are some of the key features of this module:
• Time: hours, minutes and seconds
• 24-hour format (military time)
• Visibility of one-half second period
• Provides calendar: Weekday, date, month and
year
• Alarm intervals are configurable for half of a
second, one second, 10 seconds, one minute, 10
minutes, one hour, one day, one week, one month
and one year
• Alarm repeat with decrementing counter
• Alarm with indefinite repeat: Chime
• Year range: 2000 to 2099
• Leap year correction
• BCD format for smaller firmware overhead
• Optimized for long-term battery operation
• Fractional second synchronization
• User calibration of the clock crystal frequency with
auto-adjust
• Calibration range: 0.66 seconds error per month
• Calibrates up to 260 ppm of crystal error
• Requirements: External 32.768 kHz clock crystal
• Alarm pulse or seconds clock output on
RTCC pin
32.768 kHz Input
from Secondary
Oscillator (SOSC)
CAL<9:0>
RTCC Prescalers
0.5s
Alarm
Event
RTCC Timer
Comparator
Compare Registers
with Masks
Repeat Counter
RTCVAL
ALRMVAL
RTCTIME
HR, MIN, SEC
RTCDATE
YEAR, MONTH, DAY, WDAY
ALRMTIME
HR, MIN, SEC
ALRMDATE
MONTH, DAY, WDAY
RTCC Interrupt Logic
Set RTCC Flag
Alarm Pulse ⁰
Seconds Pulse ¹
RTCC
RTSECSEL
RTCOE
 2011-2012 Microchip Technology Inc.
Preliminary
DS61168E-page 191