Datasheet
RL78/L12    CHAPTER 7 REAL-TIME CLOCK 
R01UH0330EJ0200 Rev.2.00      297 
Dec 13, 2013 
7.3.9 Week count register (WEEK) 
The WEEK register is an 8-bit register that takes a value of 0 to 6 (decimal) and indicates the count value of weekdays. 
It counts up in synchronization with the day counter. 
When data is written to this register, it is written to a buffer and then to the counter up to two cycles of f
RTC later. Set a 
decimal value of 00 to 06 to this register in BCD code. 
The WEEK register can be set by an 8-bit memory manipulation instruction. 
Reset signal generation clears this register to 00H. 
Figure 7-10. Format of Week Count Register (WEEK) 
Address: FFF95H After reset: 00H R/W 
Symbol 7 6 5 4 3 2 1 0 
WEEK 0 0 0 0 0 WEEK4 WEEK2 WEEK1 
Cautions  1.  The value corresponding to the month count register (MONTH) or the day count register 
(DAY) is not stored in the week count register (WEEK) automatically. After reset release, 
set the week count register as follow. 
Day WEEK 
Sunday 00H 
Monday 01H 
Tuesday 02H 
Wednesday 03H 
Thursday 04H 
Friday 05H 
Saturday 06H 
  2.  When it reads or writes from/to the register while the counter is in operation (RTCE = 1), 
follow the procedures described in the section 7.4.3 Reading/writing real-time clock. 










