CONVENIENCE TIMER

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

S-35710M A Series

11



INT Pin Interrupt Signal Output

After the RST

_______

pin changes from "L" to "H", the timer starts the operation. Then, the INT pin outputs "H" level when the

timer value matches the value written to the wake-up time register. When the INT pin outputs "H" level, the timer stops and

maintains the timer value.

The timer is reset by inputting "L" to the RST

_______

pin. After that, if "H" is input to the RST

_______

pin, the INT pin is set to "L" and

the timer restarts the count-up action.

1. Write mode

If write operation is performed to the wake-up time register during the count-up action, the action will be restarted after

resetting the timer. This operation is called "write mode". Before the timer value matches the value written to the

wake-up time register, if "L" is input to the RST

_______

pin, the timer is reset.

RST

INT

2 s

1 s

Timer

Wake-up time

register

Timer and wake-up time register

are reset

Timer and wake-up time register

are reset

Count-up action

starts

Count-up action

starts

Timer is reset

and count-up action

restarts

Timer is reset

and count-up

action restarts

Count-up action

stops

Count-up action

stops

Figure 10 Output Timing of Handshake Time-out

2. Read mode

After the timer starts to operate, if write operation is not performed to the wake-up time register, the interrupt signal is

not output from the INT pin. The timer stops at "FFFFFF h". The timer value during timing can be confirmed by reading

the time register. This operation is called "read mode".

In order for the timer to operate again, set the RST

_______

pin from "L" to "H" or perform write operation to the wake-up time

register. Regarding the detail when write operation is not performed to the wake-up time register, refer to Figure 11.

Regarding the status transition for the S-35710M, refer to Figure 12.

RST

Timer

Wake-up time

register

INT

Timer and wake-up time register

are reset

Timer reset

Timer reset

Count-up action starts

Count-up action starts

Count-up action starts

Count-up action

stops

Count-up action

stops

No INT pin interrupt signal output when not writting to

wake-up time register

Figure 11 When Write Operation is not Performed to the Wake-up Time Register