Datasheet
Section 10 Realtime Clock (RTC) 
    Rev. 3.00 Mar. 15, 2006 Page 151 of 526 
   REJ09B0060-0300 
10.3.3  Hour Data Register (RHRDR) 
RHRDR counts the BCD-coded hour value on the carry generated once per hour by RMINDR. 
The setting range is either decimal 00 to 11 or 00 to 23 by the selection of the 12/24 bit in 
RTCCR1. 
Bit Bit Name 
Initial 
Value R/W Description 
7 BSY — R RTC Busy 
This bit is set to 1 when the RTC is updating (operating) 
the values of second, minute, hour, and day-of-week 
data registers. When this bit is 0, the values of second, 
minute, hour, and day-of-week data registers must be 
adopted. 
6 —  0  — Reserved 
This bit is always read as 0. 
5 
4 
HR11 
HR10 
— 
— 
R/W 
R/W 
Counting Ten's Position of Hours 
Counts on 0 to 2 for ten's position of hours. 
3 
2 
1 
0 
HR03 
HR02 
HR01 
HR00 
— 
— 
— 
— 
R/W 
R/W 
R/W 
R/W 
Counting One's Position of Hours 
Counts on 0 to 9 once per hour. When a carry is 
generated, 1 is added to the ten's position. 










