PIC18F25J50 MICROCHIP [Microchip Technology], PIC18F25J50 Datasheet - Page 238

• Manufacturer Part Number: PIC18F25J50
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F46J50 FAMILY
17.2.2
As mentioned earlier, the RTCC module is intended to
be clocked by an external Real-Time Clock (RTC) crystal
oscillating at 32.768 kHz, but can also be clocked by the
INTRC. 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 T1CKI input) 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 RTC clock can
be
RTSECSEL<1:0> bits in the PADCFG 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
DS39931D-page 238
carry to the Day field
Year field
Table
use of the RTCC
Note 1:
32.768 kHz XTAL
from T1OSC
Internal RC
CONFIG 3L<1>
brought
17-1)
CLOCK SOURCE
DIGIT CARRY RULES
Real-Time Clock Enable
Writing to the lower half of the MINSEC register resets all counters, allowing fraction of a second synchronization;
clock prescaler is held in Reset when RTCEN =
out
to
CLOCK SOURCE MULTIPLEXING
Second
the
RTCC
pin
Clock Prescaler
Hour:Minute
1:16384
by
the
(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
Half-Second
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:
Clock
Day
Wednesday
Thursday
Saturday
Tuesday
Monday
Sunday
Friday
Half Second
DAY OF WEEK SCHEDULE
Day of Week
Month
Section 17.2.9
 2011 Microchip Technology Inc.
(1)
One-Second Clock
“Calibration”.)
Year
0
1
2
3
4
5
6
Table
17-2.