Day-Of-Week Counter (Rwkcnt) - Hitachi SH7751 Hardware Manual

11.2.5

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, or in standby mode.
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
—
Initial value: 0
R/W: R
Day-of-week code
Day of week
6 5
— —
0 0
R R
0 1
Sun Mon
4 3
— —
0 0
R R
2 3
Tue Wed
Rev. 3.0, 04/02, page 269 of 1064
2 1
Day-of-week code
Undefined Undefined Undefined
R/W R/W
4 5
Thu Fri
0
R/W
6
Sat