Microchip Technology MA330019-2 Data Sheet
© 2007-2012 Microchip Technology Inc.
DS70292G-page 289
dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04, AND dsPIC33FJ128GPX02/X04
24.0 REAL-TIME CLOCK AND
CALENDAR (RTCC)
This chapter discusses the Real-Time Clock and
Calendar (RTCC) module, available on
dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04,
and dsPIC33FJ128GPX02/X04 devices, and its
operation. The following are some of the key
features of this module:
Calendar (RTCC) module, available on
dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04,
and dsPIC33FJ128GPX02/X04 devices, and its
operation. The following are some of the key
features of this module:
• 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
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.
• 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
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.
FIGURE 24-1:
RTCC BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the dsPIC33FJ32GP302/304,
dsPIC33FJ64GPX02/X04, and
dsPIC33FJ128GPX02/X04 families of
devices. It is not intended to be a compre-
hensive reference source. To comple-
ment the information in this data sheet,
refer to Section 37. “Real-Time Clock
and Calendar (RTCC)” (DS70301) of the
“dsPIC33F/PIC24H Family Reference
Manual”, which is available from the
Microchip website (
dsPIC33FJ64GPX02/X04, and
dsPIC33FJ128GPX02/X04 families of
devices. It is not intended to be a compre-
hensive reference source. To comple-
ment the information in this data sheet,
refer to Section 37. “Real-Time Clock
and Calendar (RTCC)” (DS70301) of the
“dsPIC33F/PIC24H Family Reference
Manual”, which is available from the
Microchip website (
www.microchip.com
).
2: Some registers and associated bits
described in this section may not be avail-
able on all devices. Refer to
able on all devices. Refer to
in this data
sheet for device-specific register and bit
information.
information.
RTCC Prescalers
RTCC Timer
Comparator
Compare Registers
Repeat Counter
with Masks
RTCC Interrupt Logic
RCFGCAL
ALCFGRPT
Alarm
Event
32.768 kHz Input
from SOSC Oscillator
0.5s
RTCC Clock Domain
Alarm Pulse
RTCC Interrupt
CPU Clock Domain
RTCVAL
ALRMVAL
RTCC Pin
RTCOE