SH7751 Datasheet, PDF (397/1224 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

11. Realtime Clock (RTC)
Bits 7 to 5 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
—
—
— 10-month
unit
1-month units
Initial value:
0
0
0
Undefined Undefined Undefined Undefined Undefined
R/W: R
R
R
R/W
R/W
R/W
R/W
R/W
11.2.8 Year Counter (RYRCNT)
RYRCNT is a 16-bit readable/writable register used as a counter for setting and counting the
BCD-coded year value in the RTC. It counts on the carry generated once per year by the month
counter.
The setting range is decimal 0000 to 9999. 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.
RYRCNT is not initialized by a power-on or manual reset, or in standby mode.
Bit: 15
14
13
12
11
10
9
8
1000-year units
100-year units
Initial value: Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
R/W: R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Bit:
7
6
5
4
3
2
1
0
10-year units
1-year units
Initial value: Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
R/W: R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Rev.4.00 Oct. 10, 2008 Page 299 of 1122
REJ09B0370-0400