Datasheet
Section 10 Realtime Clock (RTC) 
Rev. 3.00 Mar. 15, 2006 Page 152 of 526 
REJ09B0060-0300   
10.3.4  Day-of-Week Data Register (RWKDR) 
RWKDR counts the BCD-coded day-of-week value on the carry generated once per day by 
RHRDR. The setting range is decimal 0 to 6 using bits WK2 to WK0. 
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 
5 
4 
3 
— 
— 
— 
— 
0 
0 
0 
0 
— 
— 
— 
— 
Reserved 
These bits are always read as 0. 
2 
1 
0 
WK2 
WK1 
WK0 
— 
— 
— 
R/W 
R/W 
R/W 
Day-of-Week Counting 
Day-of-week is indicated with a binary code 
000: Sunday 
001: Monday 
010: Tuesday 
011: Wednesday 
100: Thursday 
101: Friday 
110: Saturday 
111: Reserved (setting prohibited) 










