CONVENIENCE TIMER

AUTOMOTIVE, 125°C OPERATION, 2-WIRE TIMER WITH BUILT-IN QUARTZ CRYSTAL

S-35710M A Series

18



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.

1

2

8

9

SCL

SDA

(S-35710M 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 21 SDA Release Method