beautypg.com

FUJITSU MB91460 SERIES FR60 User Manual

Page 292

background image

276

Chapter 20 Software Watchdog Timer

4.Register

The software reset occurred flag (SRST) is cleared to “0” after reading.

• Bit2: Low voltage reset occurred flag

Indicates whether a reset (INIT) was triggered by the low voltage detection.

The low voltage reset occurred flag (LINIT) is cleared to “0” after reading.

• Bit1-0: Watchdog interval time selection

• A total of four watchdog interval times are available to be selected.

• Only the data firstly written after a reset is valid, and the other data sets are invalid.

• Watchdog interval time selection bit can be read to know the set value.

Note: For more information on bits used for timers other than the watchdog timer, refer to

Chapter 9 Reset

(Page No.139)

”.

1

RST has been triggered by a software reset.

LINIT

Meaning

0

No INIT has been triggered by the low voltage detection.

1

INIT has been triggered by the low voltage detection.

WT1

WT0

The minimum writing interval required for WPR

so that the watchdog timer may not be reset

Interval between the time when WPR is last

written with 5A

H

and when the watchdog is

reset

(Interval time of the timebase counter

selection bit)

(Watchdog interval time)

0

0

Φ × 2

20

(Initial value)

Φ × 2

20

to

Φ × 2

21

0

1

Φ × 2

22

Φ × 2

22

to

Φ × 2

23

1

0

Φ × 2

24

Φ × 2

24

to

Φ × 2

25

1

1

Φ × 2

26

Φ × 2

26

to

Φ × 2

27

(

Φ: Base clock)