Datasheet

RL78/L12 CHAPTER 7 REAL-TIME CLOCK
R01UH0330EJ0200 Rev.2.00 285
Dec 13, 2013
Figure 7-1. Block Diagram of Real-time Clock
INTRTC
RTCE
WUTMM
CK0
RCLOE1 AMPM CT2 CT1 CT0
RTCE
AMPM
CT0 to CT2
WUTMMCK0
fRTC
fSUB
fIL
RWAIT
WALE WALIE WAFG RWAIT
RWST
RIFG
RWST
RIFG
LCD driver/
controller
Real-time clock control register 1
Real-time clock control register 0
Subsystem clock supply
mode control register
(OSMC)
Alarm week
register
(ALARMWW)
(7-bit)
Alarm hour
register
(ALARMWH)
(6-bit)
Alarm minute
register
(ALARMWM)
(7-bit)
Year count
register
(YEAR)
(8-bit)
Month count
register
(MONTH)
(5-bit)
Week count
register
(WEEK)
(3-bit)
Day count
register
(DAY)
(6-bit)
Hour count
register
(HOUR)
(6-bit)
Minute count
register
(MIN)
(7-bit)
Second
count
register
(SEC)
(7-bit)
Wait control
0.5
seconds
1 seconds
Internal
counter
(16-bit)
Selector
Selector
Buffer
Buffer
Buffer
Buffer Buffer Buffer Buffer
Count enable/
disable circuit
Watch error
correction
register
(SUBCUD)
(8-bit)
Internal bus
1 month1 year
1 day 1 hour
1 minute
RTC1HZ/INTP3/
SEG18
Caution The count of year, month, week, day, hour, minutes and second can only be performed when a
subsystem clock (fSUB = 32.768 kHz) is selected as the operation clock of the real-time clock.
When the low-speed on-chip oscillator clock (f
IL = 15 kHz) is selected, only the constant-period
interrupt function is available. The 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) × fSUB/fIL.
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