S35710M Datasheet, PDF (18/29 Pages) Seiko Instruments Inc – FOR AUTOMOTIVE 125°C OPERATION 2-WIRE BUILT-IN QUARTZ CRYSTAL CONVENIENCE TIMER

FOR AUTOMOTIVE 125°C OPERATION 2-WIRE BUILT-IN QUARTZ CRYSTAL CONVENIENCE TIMER
S-35710M
Rev.1.1_00
 Release of SDA
_______
The RST pin of the S-35710M does not perform the reset operation of the communication interface. Therefore, the
stop condition is input to reset the internal interface circuit usually.
However, the S-35710M does not accept the stop condition from the master device when in the status that SDA outputs
"L" (at the time of acknowledge outputting or reading). Consequently, it is necessary to finish the acknowledge output or
read operation. Figure 21 shows the SDA release method.
First, input the start condition from the master device (since SDA of the S-35710M outputs "L", the S-35710M can not
detect the start condition). Next, input the clocks for 1-byte data access (9 clocks) from SCL. During the time, release
SDA of the master device. By this, the SDA input / output before communication interrupt is completed, and SDA of the
S-35710M becomes release status. Continuously, if the stop condition is input, the internal circuit resets and the
communication returns to normal status.
It is strongly recommended that the SDA release method is performed at the time of system initialization after the power
supply voltage of the master device is raised.
Start condition
SCL
Clocks for 1-byte data access
Stop condition
12
8
9
SDA
(Master device output)
SDA
"L"
(S-35710M output)
"L"
SDA
"L" or High-Z
"L" or High-Z
High-Z
Figure 21 SDA Release Method
18