beautypg.com

Rainbow Electronics W90N745CDG User Manual

Page 299

background image

W90N745CD/W90N745CDG

Publication Release Date: September 22, 2006

-

295

-

Revision

A2

Continued

BITS

DESCRIPTIONS

[6]

WTIE

Watchdog Timer Interrupt Enable

0 = Disable the Watchdog timer interrupt
1 = Enable the Watchdog timer interrupt

[5:4]

WTIS

Watchdog Timer Interval Select
These two bits select the interval for the Watchdog timer. No matter
which interval is chosen, the reset timeout is always occurred 512
WDT clock cycles later than the interrupt timeout.

WTIS

Interrupt

Timeout

Reset Timeout

Real Time Interval

(CLK=15MHz/256)

00 2

14

clocks

2

14

+ 1024

clocks

0.28 sec.

01 2

16

clocks

2

16

+ 1024

clocks

1.12 sec.

10 2

18

clocks

2

18

+ 1024

clocks

4.47 sec.

11 2

20

clocks

2

20

+ 1024

clocks

17.9 sec.

[3]

WTIF

Watchdog Timer Interrupt Flag
If the Watchdog timer interrupt is enabled, then the hardware will set
this bit to indicate that the Watchdog timer interrupt has occurred. If
the Watchdog timer interrupt is not enabled, then this bit indicates that
a timeout period has elapsed.

0 = Watchdog timer interrupt does not occur
1 = Watchdog timer interrupt occurs

NOTE: This bit is read only, but can be cleared by writing 1 to this bit.

[2]

WTRF

Watchdog Timer Reset Flag
When the Watchdog timer initiates a reset, the hardware will set this
bit. This flag can be read by software to determine the source of
reset. Software is responsible to clear it up manually. If WTRE is
disabled, then the Watchdog timer has no effect on this bit.

0 = Watchdog timer reset does not occur
1 = Watchdog timer reset occurs

NOTE: This bit is read only, but can be cleared by writing 1 to this bit.