Microchip Technology MA330026 Data Sheet
2011-2014 Microchip Technology Inc.
DS70000652F-page 243
dsPIC33FJ16(GP/MC)101/102 AND dsPIC33FJ32(GP/MC)101/102/104
21.0
REAL-TIME CLOCK AND
CALENDAR (RTCC)
CALENDAR (RTCC)
This chapter discusses the Real-Time Clock
and Calendar (RTCC) module, available
on
and Calendar (RTCC) module, available
on
dsPIC33FJ16(GP/MC)101/102 and
dsPIC33FJ32(GP/MC)101/102/104 devices, and its
operation.
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.
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
clock is from 00:00:00 (midnight) on January 1, 2000 to
23:59:59 on December 31, 2099.
with automatic leap year detection. The range of the
clock is from 00:00:00 (midnight) on January 1, 2000 to
23:59:59 on December 31, 2099.
The hours are available in 24-hour (military time)
format. The clock provides a granularity of one second
with half-second visibility to the user.
format. The clock provides a granularity of one second
with half-second visibility to the user.
FIGURE 21-1:
RTCC BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the dsPIC33FJ16(GP/MC)101/102
and dsPIC33FJ32(GP/MC)101/102/104
device families of devices. It is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to “Real-Time Clock
and Calendar (RTCC)” (DS70310) in the
“dsPIC33/PIC24 Family Reference Man-
ual”, which is available on the Microchip
web site (
and dsPIC33FJ32(GP/MC)101/102/104
device families of devices. It is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to “Real-Time Clock
and Calendar (RTCC)” (DS70310) in the
“dsPIC33/PIC24 Family Reference Man-
ual”, which is available on the Microchip
web site (
www.microchip.com
).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
RTCC Prescalers
RTCC Timer
Comparator
Compare Registers
Repeat Counter
with Masks
RTCC Interrupt Logic
RCFGCAL
ALCFGRPT
Alarm
Event
Event
32.768 kHz Input
from SOSC Oscillator
from SOSC Oscillator
0.5s
RTCC Clock Domain
Alarm Pulse
RTCC Interrupt
CPU Clock Domain
RTCVAL
ALRMVAL
RTCC Pin
RTCOE