H838799 Datasheet, PDF (262/686 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 10 Realtime Clock (RTC)
10.5 Interrupt Sources
There are eight kinds of RTC interrupts: a free-running counter overflow, week interrupt, day
interrupt, hour interrupt, minute interrupt, one-second interrupt, 0.5-second interrupt, and 0.25-
second interrupt.
When using an interrupt, set the IENRTC (RTC interrupt request enable) bit in IENR1 to 1 last
after other registers are set.
When an interrupt request of the RTC occurs, the corresponding flag in RTCFLG is set to 1. When
clearing the flag, write 0.
Table 10.2 shows a interrupt sources.
Table 10.2 Interrupt Sources
Interrupt Name
Overflow interrupt
Week periodic interrupt
Day periodic interrupt
Hour periodic interrupt
Minute periodic interrupt
One-second periodic
interrupt
0.5-second periodic
interrupt
0.25-second periodic
interrupt
Interrupt Source
Interrupt Enable Bit
Occurs when the free running counter is
overflowed.
FOIE
Occurs every week when the day-of-week date WKIE
register value becomes 0.
Occurs every day when the day-of-week date DYIE
register is counted.
Occurs every hour when the hour date register HRIE
is counted.
Occurs every minute when the minute date
register is counted.
MNIE
Occurs every second when the one-second
date register is counted.
1SEIE
Occurs every 0.5 seconds.
05SEIE
Occurs every 0.25 seconds.
025SEIE
Rev. 1.00 Jul. 11, 2007 Page 224 of 644
REJ09B0380-0100