HD6417706 RENESAS [Renesas Technology Corp], HD6417706 Datasheet - Page 389

• Manufacturer Part Number: HD6417706
• Description: Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

13.4.4
Figure 13.4 shows how to use the alarm function.
Alarms can be generated using seconds, minutes, hours, day of the week, date, month, or any
combination of these. Set the ENB bit (bit 7) 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
placed to 0.
When the clock and alarm times match, 1 is set in the AF bit (bit 0) in RCR1. Alarm detection can
be checked by reading this bit, but normally it is done by interrupt. If 1 is placed in the AIE bit (bit
3) in RCR1, an interrupt is generated when an alarm occurs.
Alarm Function
(wait for interrupt or
Set whether to use
Monitor alarm time
check alarm flag)
Clear alarm flag
alarm interrupt
Set alarm time
Clock running
Figure 13.4 Using the Alarm Function
Disable interrupt to prevent errorneous
interruption (AIE bit in RCR1 is cleared).
Then write 1.
Always reset, since the flag may have been
set while the alarm time was being set
(AF bit in RCR1 is cleared).
Rev. 4.00, 03/04, page 343 of 660