FOR AUTOMOTIVE 125°C OPERATION 2-WIRE CONVENIENCE TIMER

S-35710 Series

Seiko Instruments Inc.

11



INT Pin Interrupt Signal Output

The INT pin interrupt signal output (time-out type) can be selected from either of the following:

• One-shot loop time-out

• Handshake time-out

1. One-shot loop time-out

One-shot loop time-out is a type to output "L" pulse interrupt signal repeatedly from the INT pin.

After the RST

_______

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

the timer value matches the value written to the wake-up time register. After that, the S-35710 Series resets the timer

automatically, and restarts a count-up action.

Remark The above description is the example of Nch open-drain output product.

In CMOS output product, the INT pin output is the inverse logic of Nch open-drain output product.

1. 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".

If "L" is input to the RST

_______

pin before the timer value matches the value written to the wake-up time register, the timer

and the wake-up time register are reset.

RST

Timer

Wake-up time

register

INT

7.8 ms

2s

1 s

7.8 ms

2 s

7.8 ms

1s

1s

7.8 ms

INT pin performs the one-shot output periodically

Count-up action starts Timer is reset and

count-up action

restarts

Timer and wake-up time register

are reset

Timer and wake-up time register

are reset

Timer is reset and

count-up action restarts

Count-up action

starts

Figure 12 Output Timing of One-shot Loop Time-out (Nch Open-drain Output)

RST

Timer

Wake-up time

register

7.8 ms

2s

1 s

7.8 ms

2 s

7.8 ms

1s

1s

7.8 ms

INT pin performs the one-shot output periodically

Timer is reset

and count-up action

restarts

INT

Timer and wake-up time register

are reset

Timer and wake-up time register

are reset

Timer is reset

and count-up action

restarts

Count-up action

starts

Count-up action starts

Figure 13 Output Timing of One-shot Loop Time-out (CMOS Output)