WAKE-UP TIMER IC

PROGRAMMABLE WAKE-UP TIMER IC

S-35710 Series

16



Serial Interface

1. Start condition

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

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

Start condition

Stop condition

SDA

SCL

Figure 20 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 21, assume that the S-35710 Series 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-35710

Series, as an acknowledge, sets SDA to "L" during the 9th bit pulse. The access operation is not performed properly

when the S-35710 Series does not output an acknowledge.

1

8

9

Acknowledge output

(Active "L")

Start condition

SCL

(S-35710 input)

SDA

(Master device output)

SDA

(S-35710 output)

High-Z

Release SDA

High-Z

Figure 21 Acknowledge Output Timing