Filter
Top Products
RL78/G1A CHAPTER 7 REAL-TIME CLOCK
CHAPTER 7 REAL-TIME CLOCK
7.1 Functions of Real-time Clock
The real-time clock has the following features.
• Having counters of year, month, week, day, hour, minute, and second, and can count up to 99 years.
• Constant-period interrupt function (period: 0.5 seconds, 1 second, 1 minute, 1 hour, 1 day, 1 month)
• Alarm interrupt function (alarm: week, hour, minute)
• Pin output function of 1 Hz (48 and 64-pin products only)
The real-time clock interrupt signal (INTRTC) can be utilized for wakeup from STOP mode and triggering an A/D
converter’s SNOOZE mode.
<R>
Caution The count of year, month, week, day, hour, minutes and second can only be performed when a
subsystem clock (f
SUB = 32.768 kHz) is selected as the operation clock of the real-time clock.
When the low-speed oscillation clock (f
IL = 15 kHz (TYP.)) is selected, only the constant-period
interrupt function is available. The 25- to 32-pin products have the constant-period interrupt
function only, because these products have no subsystem clock.
However, the constant-period interrupt interval when f
IL is selected will be calculated with the
constant-period (the value selected with RTCC0 register) × f
SUB/fIL.
R01UH0305EJ0200 Rev.2.00 292
Jul 04, 2013