CONVENIENCE TIMER

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

S-35710M A Series

17

7. Read operation of wake-up time register

Perform the read operation of the wake-up time register with the restart format. Regarding the restart format, refer to

"4. Data transmission format".

When performing the read operation of the wake-up time register, set the RST

_______

pin to "H". If the RST

_______

pin is set to "L",

the time register data is read.

Transmit the start condition and the slave address from the master device. The slave address of the S-35710M is

specified to "0110010". Next, transmit "0" to the read / write bit.

B7 in the 2nd byte is an address pointer. Set B7 to "0" when reading the wake-up time register. Next, transmit the

dummy data to B6 to B1. Make sure to set B0 to "1" since it is a test bit. This processing is called "dummy write".

Then transmit the start condition, the slave address and the read / write bit. The data of the wake-up time register can

be read when the read / write bit is set to "1".

Consequently, the data of the wake-up time register is output from the S-35710M. Each byte from B7 is transmitted.

When the read operation of the wake-up time register is finished, transmit "1" (NO_ACK) to the acknowledge after B0

output from the master device, and then transmit the stop condition.

The wake-up time register is a 3-byte register. "1" is read if the read operation is performed continuously after reading

3 bytes of the wake-up time register.

Regarding the wake-up time register, refer to " Configuration of Registers".

Moreover, the internal address pointer is reset if recognizing the stop condition. Therefore, do not transmit the stop

condition after dummy write operation. The time register is read if performing the read operation of the register after

transmitting the stop condition.

19

18

1

9

18

27

36

SCL

1

0

1

0

0

1

1

0

B1

B7

B0

B7

B0

B7

B0

B7

SDA

Wake-up time register (3-byte)

0

B0

B7

Dummy data

*1

Dummy write

Slave address

(0110010)

1

0

1

0

0

1

1

0

B1R/W

0

R/W

B7

Slave address

(0110010)

Make sure to set B0 to "1" since it is a test bit.

Input NO_ACK after

the 3rd byte transmission.

Set B7 as an address pointer.

*1. Set B6 to B1 to "0" or "1" since they are dummy data.

: S-35710M output data

: Master device input data

Figure 20 Read Timing of Wake-up Time Register