S-35390A Seiko Instruments, S-35390A Datasheet - Page 22

• Manufacturer Part Number: S-35390A
• Description: 2-Wire Real Time Clock
• Manufacturer: Seiko Instruments

22
2-WIRE REAL-TIME CLOCK
S-35390A
(5) Per-minute steady interrupt output 2 (
Caution
Serial
communication
When the first minute carry is performed after the INT1 pin output mode is set as per-minute steady
interrupt 2 using status register_2, low is output from the INT1 pin for a period of 7.9 ms in
synchronization with the minute carry processing inside the IC. However, when real-time data is read,
the minute carry processing is delayed by a maximum of 0.5 s and accordingly low output from the
INT1 pin is also delayed by a maximum of 0.5 s. When the second data is rewritten by a real-time data
write command, counting starts from the rewritten second data and as a result, the output interval
during that period may become either longer or shorter.
(b) During realtime data read
(a) During normal operation
INT1 pin
INT1 pin
Realtime data
read command
1. When changing an output mode, give care to the state of INT1 register_1 (or INT1
2. If per-minute edge interrupt output or per-minute steady interrupt output is chosen,
Minute-carry processing
INT1 register_1 (or INT1 register_2) has no meaning.
register_2) and the output.
7.9 ms
Minute-carry processing
Figure 21 Timing of Per-Minute Steady Interrupt Output 2
Realtime data reading
7.9 ms
Realtime data
read command
Seiko Instruments Inc.
(Normal minute-
carry processing)
60 s
60 s
INT pin output mode only)
0.5 s Max.
Minute-carry processing
1
Realtime data reading
Minute-carry processing
7.9 ms
7.9 ms
60 s
60 s
Realtime data
write command
Minute-carry processing
Minute-carry processing
Realtime data writing (X s)
7.9 ms
7.9 ms
60 s
(60 − X) s
Rev.1.2
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