FOR AUTOMOTIVE 125°C OPERATION 2-WIRE CONVENIENCE TIMER

S-35710 Series

22



Release of SDA

The RST

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pin of the S-35710 Series 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-35710 Series 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 30 shows the SDA release method.

First, input the start condition from the master device (since SDA of the S-35710 Series outputs "L", the S-35710 Series

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-35710 Series 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.

12

8

9

SCL

SDA

(S-35710 output)

"L" or High-Z

"L"

High-Z

"L" or High-Z

Start condition

Clocks for 1-byte data access

Stop condition

SDA

(Master device output)

"L"

SDA

Figure 30 SDA Release Method