SH7720 Datasheet, PDF (630/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 17 Realtime Clock (RTC)
17.3.6 Date Counter (RDAYCNT)
RDAYCNT is used for setting/counting in the BCD-coded date section. The count operation is
performed by a carry for each day of the hour counter.
Though the range of date which can be set is 01 to 31 (decimal). Errant operation will result if any
other value is set. Carry out write processing after stopping the count operation with the START
bit in RCR2.
RDAYCNT is not initialized by a power-on reset or manual reset, or in standby mode.
The range of date changes with each month and in leap years. Please confirm the correct setting.
Leap years are recognized by dividing the year counter values by 400, 100, and 4 and obtaining a
fractional result of 0. The year counter value of 0000 is included in the leap year.
Bit
7, 6
5, 4
3 to 0
Bit Name

Initial Value R/W
All 0
R

Undefined R/W

Undefined R/W
Description
Reserved
These bits are always read as 0. The write value
should always be 0.
Counting Ten’s Position of Dates
Counting One’s Position of Dates
Counts on 0 to 9 once per date. When a carry is
generated, 1 is added to the ten’s position.
Rev. 3.00 Jan. 18, 2008 Page 568 of 1458
REJ09B0033-0300