PIC18F24J11 MICROCHIP [Microchip Technology], PIC18F24J11 Datasheet - Page 240

• Manufacturer Part Number: PIC18F24J11
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F46J11 FAMILY
17.2.2
As mentioned earlier, the RTCC module is intended to
be clocked by an external Real-Time Clock crystal
oscillating at 32.768 kHz, but also can be clocked by
the INTRC oscillator. The RTCC clock selection is
decided by the RTCOSC bit (CONFIG3L<1>).
FIGURE 17-4:
17.2.2.1
The RTCC module can be clocked by an external,
32.768 kHz crystal (Timer1 oscillator) or the INTRC
oscillator, which can be selected in CONFIG3L<1>.
If the Timer1 oscillator will be used as the clock source
for the RTCC, make sure to enable it by setting
T1CON<3> (T1OSCEN). The selected clock can be
brought out to the RTCC pin by the RTSECSEL<1:0>
bits in the PADCFG1 register.
17.2.3
This section explains which timer values are affected
when there is a rollover.
• Time of Day: From 23:59:59 to 00:00:00 with a
• Month: From 12/31 to 01/01 with a carry to the
• Day of Week: From 6 to 0 with no carry (see
• Year Carry: From 99 to 00; this also surpasses the
DS39932D-page 240
32.768 kHz XTAL
from T1OSC
Internal RC
CONFIG 3L<1>
carry to the Day field
Year field
Table
use of the RTCC
Note 1:
17-1)
CLOCK SOURCE
DIGIT CARRY RULES
Writing to the lower half of the MINSEC register resets all counters, allowing fraction of a second synchronization;
the clock prescaler is held in Reset when RTCEN =
Real-Time Clock Enable
CLOCK SOURCE MULTIPLEXING
Second
Clock Prescaler
Hour:Minute
1:16384
(1)
0
.
Day of Week
module to yield an error of 3 seconds or less per month.
Calibration of the crystal can be done through this
(For further details, see Section 17.2.9 “Calibration”.)
For the day to month rollover schedule, see
Considering that the following values are in BCD
format, the carry to the upper BCD digit will occur at a
count of 10 and not at 16 (SECONDS, MINUTES,
HOURS, WEEKDAY, DAYS and MONTHS).
TABLE 17-1:
Half-Second
Clock
Day
Wednesday
Thursday
Saturday
Tuesday
Monday
Sunday
Friday
Half Second
DAY OF WEEK SCHEDULE
Day of Week
Month
 2011 Microchip Technology Inc.
(1)
One-Second Clock
Year
0
1
2
3
4
5
6
Table
17-2.