S-35770E01A-K8T2U Datasheet, PDF (15/26 Pages) Seiko Instruments Inc – CONVENIENCE TIMER

Rev.1.2_00
FOR AUTOMOTIVE 125°C OPERATION 2-WIRE COUNTER CONVENIENCE TIMER
S-35770 Series
4. Data transmission format
After the start condition transmission, the 1st byte is a slave address and a command (read / write bit) that shows the
transmission direction at the 2nd byte or subsequent bytes.
The slave address of the S-35770 Series is specified to "0110010". The data can be written to the free register when
read / write bit is "0", and the data of count register or the free regiister can be read when read / write bit is "1".
When the data can be written to the free register, input the data from the master device in order of B7 to B0. The
acknowledge ("L") is output from the S-35770 Series whenever a one-byte data is input.
When the data of the count register or the free register can be read, the data from the S-35770 Series is output in
order of B7 to B0 in byte unit. Input the acknowledge ("L") from the master device whenever a one-byte data is input.
However, do not input the acknowledge for the last byte (NO_ACK). By this, the end of the data read is informed.
After the master device receives / transmits the acknowledge for the last byte data, input the stop condition to the
S-35770 Series to finish the access operation.
When the master device inputs start condition instead of stop condition, the S-35770 Series becomes restart condition,
and can transmit / receive the data if the master device inputs the slave address continuously.
1
9
18
27
36
45
SCL
Data write
format
Data read
format
SDA ^ST Slave address ^{0 A}
B7
B1 R/W B7
SDA _{ST Slave address 1 A}
B7
B1 R/W B7
Data
Data
A
B0 B7
A
B0 B7
Data
Data
A
B0 B7
A
B0 B7
Data
Data
A
B0 B7
Data
A SP
B0
A SP
B0
Restart format _{SDA ST Slave address 0 A}
Data
A
Data
A
Data
A
Data
A
B7
B1 R/W B7
B0 B7
B0 B7
B0 B7
B0
ST _{Slave address} 1 A
B7
B1 R/W B7
Data
: Master device input data
: S-35770 output data
A
Data
A
Data
A SP
B0 B7
B0 B7
B0
ST : Start condition
SP : Stop condition
A A A : Acknowledge
Figure 21 Data Transmission Format of Serial Interface
In the time period from the start condition to the stop condition, the S-35770 Series does not detect the change of the
CLKIN pin from "L" to "H" and maintains the counter data. Therefore, the output data of the count register does not
change even if an external clock is input during a read operation of the count register.
Regarding the counter operation during communication, refer to " External Clock Signal Count Function".
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