MC68HC908LJ12 Datasheet, PDF (209/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Real Time Clock (RTC)
12.2 Introduction
This section describes the real time clock (RTC) module. The RTC
provides real time clock and calendar functions with automatic leap year
adjustments. Other functions include alarm interrupt, periodic interrupts,
and a chronograph timer.
12.3 Features
Features of the RTC module include:
• Counter registers for:
– Second
– Minute
– Hour
– Day
– Day-of-week
– Month
– Year
• Day counter with automatic month and leap year adjustment
• 1/100 seconds chronograph counter
• Seven periodic interrupts
• Alarm interrupt
Addr.
$0042
$0043
Register Name
Read:
RTC Control Register 1
(RTCCR1)
Write:
Reset:
Read:
RTC Control Register 2
(RTCCR2)
Write:
Reset:
Bit 7
ALMIE
0
0
R
0
6
5
CHRIE DAYIE
0
0
0
CHRE
CHRCLR
0
0
= Unimplemented
4
HRIE
0
RTCE
0
3
2
1
MINIE SECIE TB1IE
0
0
0
0
XTL2 XTL1
0
0
0
R = Reserved
Bit 0
TB2IE
0
XTL0
0
Figure 12-1. RTC I/O Register Summary
Technical Data
210
Real Time Clock (RTC)
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor