s-35399a03 Seiko Instruments Inc., s-35399a03 Datasheet - Page 18

• Manufacturer Part Number: s-35399a03
• Description: 2-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

18
2-WIRE REAL-TIME CLOCK
S-35399A03
8. Alarm expansion register 1 and alarm expansion register 2
Alarm expansion register 1
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.
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
B7
B7
B7
M1
Y1
D1
Writing to alarm expansion register 1
*1. Don’t care (Both of 0 and 1 are acceptable.)
Month
D2
Y2
M2
Year
Day
M4
D4
Y4
Figure 19 Alarm Expansion Register 1 and Alarm Expansion Register 2
B7
1
1
1
M8
D8
Y8
Y10 Y20 Y40 Y80
M10
D10 D20
0
0
0
0
1
0
0
A1YE A1ME
0
0
0
0
Seiko Instruments Inc.
A1DE
B0
B0
B0
1
0
1
−
Alarm expansion register 2
0
1
*1
B7
B7
B7
Y1
M1
D1
−
0
1
*1
D2
M2
Y2
B0
0
1
1
D4
Y4
M4
D8
M8
Y8
M10
D10 D20
Y10 Y20 Y40 Y80
0
A2YE A2ME
0
Rev.1.0
A2DE
B0
B0
B0
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