Datasheet
Section 10 Realtime Clock (RTC) 
    Rev. 3.00 Mar. 15, 2006 Page 159 of 526 
   REJ09B0060-0300 
10.5 Interrupt Sources 
There are five kinds of RTC interrupts: week interrupts, day interrupts, hour interrupts, minute 
interrupts, and second interrupts. 
When using an interrupt, initiate the RTC last after other registers are set. Do not set multiple 
interrupt enable bits in RTCCR2 simultaneously to 1. 
When an interrupt request of the RTC occurs, the IRRTA flag in IRR1 is set to 1. When clearing 
the flag, write 0. 
Table 10.2  Interrupt Sources 
Interrupt Name  Interrupt Source  Interrupt Enable Bit 
Overflow interrupt  Occurs when the free running counter is 
overflown. 
FOIE 
Week periodic interrupt  Occurs every week when the day-of-week 
date register value becomes 0. 
WKIE 
Day periodic interrupt  Occurs every day when the day-of-week date 
register is counted. 
DYIE 
Hour periodic interrupt  Occurs every hour when the hour date 
register is counted. 
HRIE 
Minute periodic interrupt  Occurs every minute when the minute date 
register is counted. 
MNIE 
Second periodic interrupt  Occurs every second when the second date 
register is counted. 
SCIE 










