SH7713 Datasheet, PDF (565/904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 15 Realtime Clock (RTC)
15.4 Operation
15.4.1 Initial Settings of Registers after Power-On
All the registers should be set after the power is turned on.
15.4.2 Setting Time
Figure 15.2 shows how to set the time when the clock is stopped.
Stop clock,
Write 1 to RESET and 0 to
reset divider circuit START in the RCR2 register
Set seconds, minutes,
hour, day, day of the Order is irrelevant
week, month, and year
Start clock
Write 1 to START in the
RCR2 register
Figure 15.2 Setting Time
15.4.3 Reading Time
Figure 15.3 shows how to read the time.
If a carry occurs while reading the time, the correct time will not be obtained, so it must be read
again. Part (a) in figure 15.3 shows the method of reading the time without using interrupts; part
(b) in figure 15.3 shows the method using carry interrupts. To keep programming simple, method
(a) should normally be used.
Rev.1.50 Aug. 30, 2006 Page 525 of 860
REJ09B0288-0150