Specifications subject to change without notice,contact your sales representatives for the most recent information.

12/26

Ver 2.1

SM79164 08/2006

SyncMOS Technologies International. Inc.

SM79164

3.1 Watch Dog Timer Registers:

Watch Dog Timer Registers - WDT Control Register (WDTC, $9F)

WDTE : Watch Dog Timer enable bit

CLEAR : Watch Dog Timer reset bit

PS[2:0] : Overflow period select bits

Watch Dog Key Register - (WDTKEY, $97H)

By default, the WDTC is read only. User need to write values 1EH, E1H sequentially to the WDTKEY($97H) register to

enable the WDTC write attribute, That is

MOV WDTKEY, # 1EH

MOV WDTKEY, # E1H

When WDTC is set, user need to write another values E1H, 1EH sequentially to the WDTKEY($97H) register to disable the

WDTC write attribute, That is

MOV WDTKEY, # E1H

MOV WDTKEY, # 1EH

bit-7

bit-0

WDTE

Reserve

CLEAR

Unused

Unused

PS2

PS1

PS0

Read / Write:

R/W

-

R/W

-

-

R/W

R/W

R/W

Reset value:

0

*

0

*

*

0

0

0

PS [2:0]

Overflow Period (ms)

000

2.048

001

4.096

010

8.192

011

16.384

100

32.768

101

65.536

110

131.072

111

262.144

bit-7

bit-0

WDT

KEY7

WDT

KEY6

WDT

KEY5

WDT

KEY4

WDT

KEY3

WDT

KEY2

WDT

KEY1

WDT

KEY0

Read / Write:

W

W

W

W

W

W

W

W

Reset value:

0

0

0

0

0

0

0

0