S-35740C01A-K8T2U Datasheet, PDF (16/31 Pages) Seiko Instruments Inc – Operation temperature range

FOR AUTOMOTIVE 125°C OPERATION 2-WIRE INTERVAL TIMER CONVENIENCE TIMER
S-35740 Series
Rev.1.1_00
 Serial Interface
The S-35740 Series transmits and receives various commands via I²C-bus serial interface to read / write data.
1. Start condition
When SDA changes from "H" to "L" with SCL at "H", the S-35740 Series recognizes start condition and the access
operation is started.
2. Stop condition
When SDA changes from "L" to "H" with SCL at "H", the S-35740 Series recognizes stop condition and the access
operation is completed. The S-35740 Series enters standby mode, consequently.
t_SU.STA t_HD.STA
t_SU.STO
SCL
SDA
Start condition
Stop condition
Figure 20 Start / Stop Condition
3. Data transmission and acknowledge
The data transmission is performed at every one byte after the start condition detection. Pay attention to the
specification of t_SU.DAT and t_HD.DAT when changing SDA, and perform the operation when SCL is "L". If SDA changes
when SCL is "H", the start / stop condition is recognized even during the data transmission, and the access operation
will be interrupted.
Whenever a one-byte data is received during data transimmion, the receiving device returns an acknowledge. For
example, as shown in Figure 21, assume that the S-35740 Series is a receiving device, and the master device is a
transmitting device. If the clock pulse at the 8th bit falls, the master device releases SDA. Consequently, the S-35740
Series, as an acknowledge, sets SDA to "L" during the 9th bit pulse. The access operation is not performed properly
when the S-35740 Series does not output an acknowledge.
SCL
(S-35740 input)
1
8
SDA
(Master device output)
t_SU.DAT
t_HD.DAT
SDA
(S-35740 output)
Start condition
High-Z
Figure 21 Acknowledge Output Timing
9
Release SDA
High-Z
Acknowledge
output
(Active "L")
t_AA
16