SH7763 Datasheet, PDF (832/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 22 Realtime Clock (RTC)
22.4.5 Day-of-Week Counter (RWKCNT)
RWKCNT is an 8-bit readable/writable register used as a counter for setting and counting the
BCD-coded day-of-week value in the RTC. It counts on the carry generated once per day by the
hour counter.
The setting range is decimal 0 to 6. The RTC will not operate normally if any other value is set.
Write processing should be performed after stopping the count with the START bit in RCR2, or
by using the carry flag.
RWKCNT is not initialized by a power-on or manual reset.
Bits 7 to 3 are always read as 0. A write to these bits is invalid, but the write value should always
be 0.
Bit: 7
6
5
4
3
2
1
0
— — — — — Day-of-week code
Initial value: 0
0
0
0
0 ———
R/W: R R R R R R/W R/W R/W
Day-of-week code
0
1
2
3
4
5
6
Day of week
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Rev. 1.00 Oct. 01, 2007 Page 766 of 1956
REJ09B0256-0100