S-35399A03 Datasheet, PDF (14/51 Pages) Seiko Instruments Inc – 2-WIRE REAL-TIME CLOCK

2-WIRE REAL-TIME CLOCK
S-35399A03
Rev.1.0_00
4. INT1 register and INT2 register
The INT1 and INT2 registers are to set up the output of user-set frequency, or to set up alarm interrupt. Users are able
to switch the output mode by using the status register 2. If selecting to use the output mode for alarm interrupt by
status register 2; this register works as the alarm-time data register. If selecting the output of user-set frequency by
status register 2; this register works as the data register to set the frequency for clock output. From each INT1 and
INT2 pin, a clock pulse and alarm interrupt are output.
(1) Alarm interrupt
Users can set the alarm time (the data of day of the week, hour, minute) by using the INT1 and INT2 registers which
are 3-byte data registers. The configuration of register is as well as the data register of day of the week, hour, minute,
in the real-time data register; is expressed by the BCD code. Do not set a nonexistent day. Users are necessary to set
up the alarm-time data according to the 12/24 hour expression that they set by using the status register 1.
INT1 register
W1 W2 W4 0 0 0 0 A1WE
B7
B0
INT2 register
W1 W2 W4
B7
0 0 0 A2WE
B0
H1
H2
H4
H8
H10
H20
AM /
PM
A1HE
B7
B0
H1
H2
H4
H8
H10
H20
AM /
PM
A2HE
B7
B0
m1 m2 m4 m8 m10 m20 m40 A1mE
m1 m2 m4 m8 m10 m20 m40 A2mE
B7
B0
B7
B0
Figure 12 INT1 Register and INT2 Register (Alarm Time-Data)
The INT1 register has A1WE, A1HE, A1mE at B0 in each byte. It is possible to make data valid; the data of day of the
week, hour, minute which are in the corresponded byte; by setting these bits to “1”. This is as well in A2WE, A2HE,
A2mE in the INT2 register. Regarding set-up of year, month, day, refer to “9. Alarm expansion register 1 and alarm
expansion register 2”.
Setting example: alarm time “7:00 pm” in the INT1 register
(a) 12-hour expression (status register 1 B6 = 0)
set up 7:00 PM
Data written to INT1 register
Day of week −^*1
−^*1
−^*1
−^*1
−^*1
−^*1
−^*1
0
Hour 1
1
1
0
0
0
1
1
Minute 0
0
0
0
0
0
0
1
B7
B0
*1. Don’t care (Both of 0 and 1 are acceptable).
(b) 24-hour expression (status register 1 B6 = 1)
set up 19:00 PM
Data written to INT1 register
Day of week −^*1
−^*1
−^*1
−^*1
−^*1
−^*1
−^*1
0
Hour 1
0
0
1
1
0
1^*2
1
Minute 0
0
0
0
0
0
0
1
B7
B0
*1. Don’t care (Both of 0 and 1 are acceptable).
*2. Set up the AM / PM flag along with the time setting.
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Seiko Instruments Inc.