11.2.11 Hour Alarm Register (RHRAR)
RHRAR is an 8-bit readable/writable register used as an alarm register for the RTC’s BCD-coded
hour value counter, RHRCNT. When the ENB bit is set to 1, the RHRAR value is compared with
the RHRCNT value. Comparison between the counter and the alarm register is performed for
those registers among RSECAR, RMINAR, RHRAR, RWKAR, RDAYAR, and RMONAR in
which the ENB bit is set to 1, and the RCR1 alarm flag is set when the respective values all match.
The setting range is decimal 00 to 23 + ENB bit. The RTC will not operate normally if any other
value is set.
The ENB bit in RHRAR is initialized by a power-on reset. The other fields in RHRAR are not
initialized by a power-on or manual reset, or in standby mode.
Bit 6 is always read as 0. A write to this bit is invalid, but the write value should always be 0.
Bit:
7
6
—
0
5
4
3
2
1
0
ENB
0
10-hour units
Undefined Undefined Undefined Undefined Undefined Undefined
R/W R/W R/W R/W R/W R/W
1-hour units
Initial value:
R/W:
R/W
R
11.2.12 Day-of-Week Alarm Register (RWKAR)
RWKAR is an 8-bit readable/writable register used as an alarm register for the RTC’s BCD-coded
day-of-week value counter, RWKCNT. When the ENB bit is set to 1, the RWKAR value is
compared with the RWKCNT value. Comparison between the counter and the alarm register is
performed for those registers among RSECAR, RMINAR, RHRAR, RWKAR, RDAYAR, and
RMONAR in which the ENB bit is set to 1, and the RCR1 alarm flag is set when the respective
values all match.
The setting range is decimal 0 to 6 + ENB bit. The RTC will not operate normally if any other
value is set.
The ENB bit in RWKAR is initialized by a power-on reset. The other fields in RWKAR are not
initialized by a power-on or manual reset, or in standby mode.
Bits 6 to 3 are always read as 0. A write to these bits is invalid, but the write value should always
be 0.
Rev. 6.0, 07/02, page 277 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
