HD64F3687GHV Datasheet, PDF (201/566 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 10 Realtime Clock (RTC)
Section 10 Realtime Clock (RTC)
The realtime clock (RTC) is a timer used to count time ranging from a second to a week. Figure
10.1 shows the block diagram of the RTC.
10.1 Features
• Counts seconds, minutes, hours, and day-of-week
• Start/stop function
• Reset function
• Readable/writable counter of seconds, minutes, hours, and day-of-week with BCD codes
• Periodic (seconds, minutes, hours, days, and weeks) interrupts
• 8-bit free running counter
• Selection of clock source
32-kHz
oscillator
circuit
PSS
1/4
TMOW
Clock count
control circuit
RTCCSR
RSECDR
RMINDR
RHRDR
RWKDR
RTCCR1
RTCCR2
Interrupt
[Legend]
control circuit
RTCCSR: Clock source select register
RSECDR: Second date register/free running counter data register
RMINDR: Minute date register
RHRDR: Hour date register
RWKDR: Day-of-week date register
RTCCR1: RTC control register 1
RTCCR2: RTC control register 2
PSS: Prescaler S
Figure 10.1 Block Diagram of RTC
Interrupt
RTC3000A_000020030300
Rev. 3.00 Sep. 10, 2007 Page 167 of 528
REJ09B0216-0300