SH7713 Datasheet, PDF (567/904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 15 Realtime Clock (RTC)
15.4.4 Alarm Function
Figure 15.4 shows how to use the alarm function.
Alarms can be generated using seconds, minutes, hours, day of the week, date, month, year, or any
combination of these. Set the ENB bit or YAEN bit in the register on which the alarm is placed to
1, and then set the alarm time in the lower bits. Clear the ENB bit in the register on which the
alarm is not placed to 0.
When the clock and alarm times match, 1 is set in the AF bit in RCR1. Alarm detection can be
checked by reading this bit, but normally it is done by interrupt. If 1 is set in the AIE bit in RCR1,
an interrupt is generated when an alarm occurs.
Clock running
Set whether to use
alarm interrupt
Disable interrupt to prevent errorneous
interruption.(AIE bit in RCR1 is cleared)
Then write 1.
Set alarm time
Clear alarm flag
Always clear, since the flag may have been
set while the alarm time was being set.
(Write 0 to AF of RCR1 to clear it. )
Monitor alarm time
(wait for interrupt or
check alarm flag)
Figure 15.4 Using Alarm Function
Rev.1.50 Aug. 30, 2006 Page 527 of 860
REJ09B0288-0150