SH7751 Datasheet, PDF (395/1224 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

11. Realtime Clock (RTC)
11.2.4 Hour Counter (RHRCNT)
RHRCNT is an 8-bit readable/writable register used as a counter for setting and counting the
BCD-coded hour value in the RTC. It counts on the carry generated once per hour by the minute
counter.
The setting range is decimal 00 to 23. 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.
RHRCNT is not initialized by a power-on or manual reset, or in standby mode.
Bits 7 and 6 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
6
5
4
3
2
1
0
—
10-hour units
1-hour units
0
Undefined Undefined Undefined Undefined Undefined Undefined
R
R/W
R/W
R/W
R/W
R/W
R/W
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
6
5
4
3
2
1
0
—
—
—
—
—
Day-of-week code
Initial value:
0
0
0
0
0
Undefined Undefined Undefined
R/W: R
R
R
R
R
R/W
R/W
R/W
Rev.4.00 Oct. 10, 2008 Page 297 of 1122
REJ09B0370-0400