CONVENIENCE TIMER

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

S-35710M A Series

14



Serial Interface

1. Start condition

When SDA changes from "H" to "L" with SCL at "H", the S-35710M 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-35710M recognizes stop condition and the access operation

is completed. The S-35710M enters standby mode, consequently.

Start condition

Stop condition

SDA

SCL

Figure 15 Start / Stop Condition

3. Data transmission and acknowledge

The data transmission is performed at every 1 byte after the start condition detection. Pay attention to the specification

"H", the start / stop condition is recognized even during the data transmission, and the access operation will be

interrupted.

Whenever a 1-byte data is received during data transimmion, the receiving device returns an acknowledge. For

example, as shown in Figure 16, assume that the S-35710M 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-35710M, as an acknowledge, sets SDA to "L" during the 9th bit pulse. The access operation is not performed

properly when the S-35710M does not output an acknowledge.

1

8

9

Acknowledge output

(Active "L")

Start condition

SCL

(S-35710M input)

SDA

(Master device output)

SDA

(S-35710M output)

High-Z

Release SDA

High-Z

Figure 16 Acknowledge Output Timing