S-35399A03 Datasheet, PDF (18/51 Pages) Seiko Instruments Inc – 2-WIRE REAL-TIME CLOCK

2-WIRE REAL-TIME CLOCK
S-35399A03
Rev.1.0_00
8. Alarm expansion register 1 and alarm expansion register 2
The alarm expansion register 1 and 2 are 3-byte registers. They are expansion registers for the INT1 and INT2 registers
which output alarm interrupt. Users are able to set the alarm time; the data of year, month, day. The configuration of
register is expressed by BCD code as well as the data register of year, month, day in the real-time register.
Alarm expansion register 1
Alarm expansion register 2
Y1 Y2 Y4 Y8 Y10 Y20 Y40 Y80
B7
B0
Y1 Y2 Y4 Y8 Y10 Y20 Y40 Y80
B7
B0
M1 M2 M4 M8 M10 0 A1YE A1ME
B7
B0
M1 M2 M4 M8 M10 0 A2YE A2ME
B7
B0
D1 D2 D4 D8 D10 D20 0 A1DE
D1 D2 D4 D8 D10 D20 0 A2DE
B7
B0
B7
B0
Figure 19 Alarm Expansion Register 1 and Alarm Expansion Register 2
To make the year data of alarm expansion register 1 valid, set A1YE to “1”. For the month data, set A1ME to “1”, for the
day data, set A1DE to “1”. Set as well A2ME, A2YE, A2DE in the alarm expansion register 2. Regarding how to set the
data of day of the week, hour, and minute, refer to “(1) Alarm interrupt” in “4. INT1 register and INT2 register”.
Setting example: Setting alarm time “January 31, 2015” in the alarm expansion register 1
Writing to alarm expansion register 1
Year 1
0
1
0
1
0
0
0
Month 1
0
0
0
0
−^*1
1
1
Day 1
0
0
0
1
1
−^*1
1
B7
B0
*1. Don’t care (Both of 0 and 1 are acceptable.)
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Seiko Instruments Inc.