S-35390A Seiko Instruments, S-35390A Datasheet - Page 26

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

26
2-WIRE REAL-TIME CLOCK
S-35390A
1. Start condition
2. Stop condition
3. Data transfer
The S-35390A receives various commands via an I
covers the transfer methods via I
Serial Interface
SDA
SDA
SCL
SCL
Data transfer is performed by changing the SDA line during the period that the SCL line is “L”.
The stop condition is established at the point where the SDA line changes from “L” to “H” when the SCL
If the SDA line changes during the period that the SCL line is “H”, it is recognized as the start or stop
The start condition is established at the point where the SDA line changes from “H” to “L” when the SCL
line is “H” level. All operations start with the start condition.
line is “H” level. If the stop condition is received during a readout sequence, the read operation is
discontinued and the device enters the standby mode.
condition.
t
SU. STA
Start condition
t
SU. DAT
t
HD. STA
2
Figure 23 Start Condition and Stop Condition
C-BUS.
Figure 24 Timing of Data Transfer
Seiko Instruments Inc.
t
HD. DAT
2
C-BUS serial interface to read/write data. This section
t
SU. STO
Stop condition
Rev.1.2
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