Datasheet
Section 10 Realtime Clock (RTC) 
    Rev. 3.00 Mar. 15, 2006 Page 153 of 526 
   REJ09B0060-0300 
10.3.5  RTC Control Register 1 (RTCCR1) 
RTCCR1 controls start/stop and reset of the clock timer. For the definition of time expression, see 
figure 10.2. 
Bit Bit Name 
Initial 
Value R/W Description 
7 RUN —  R/W 
RTC Operation Start 
0: Stops RTC operation 
1: Starts RTC operation 
6 12/24 — R/W Operating Mode 
0: RTC operates in 12-hour mode. RHRDR counts on 0 
to 11. 
1: RTC operates in 24-hour mode. RHRDR counts on 0 
to 23. 
5 PM  — R/W a.m./p.m. 
0: Indicates a.m. when RTC is in the 12-hour mode. 
1: Indicates p.m. when RTC is in the 12-hour mode. 
4 RST 0  R/W Reset 
0: Normal operation 
1: Resets registers and control circuits except RTCCSR 
and this bit. Clear this bit to 0 after having been set to 
1. 
3  INT  —  R/W  Interrupt Generation Timing 
0: Generates a second, minute, hour, or day-of-week 
periodic interrupt during RTC busy period. 
1: Generates a second, minute, hour, or day-of-week 
periodic interrupt immediately after completing RTC 
busy period. 
2 
1 
0 
— 
— 
— 
0 
0 
0 
— 
— 
— 
Reserved 
These bits are always read as 0. 










