w78l365a Winbond Electronics Corp America, w78l365a Datasheet - Page 18

• Manufacturer Part Number: w78l365a
• Description: 8-bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

WIDL : If this bit is set, watch-dog is enabled under IDLE mode. If cleared, watch-dog is disabled
PS2, PS1, PS0: Watch-dog prescaler timer select. Prescaler is selected when set PS2−0 as follows:
The time-out period is obtained using the following equation:
Before Watchdog time-out occurs, the program must clear the 14-bit timer by writing 1 to WDTC.6
(CLRW). After 1 is written to this bit, the 14-bit timer, prescaler and this bit will be reset on the next
instruction cycle. The Watchdog timer is cleared on reset.
Typical Watch-Dog time-out period when OSC = 20 MHz
OSC
1
×
under IDLE mode. Default is cleared.
2
WIDL
IDLE
14
Watchdog Timer Block Diagram
PS2 PS1 PS0
OSC
×
0
0
0
0
1
1
1
1
PRESCALER
PS2 PS1 PS0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
1/12
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
×
1000 12
ENW
×
mS
PRESCALER
- 18 -
CLRW
WATCHDOG TIME-OUT PERIOD
EXTERNAL
RESET
W78LE365/W78L365A
14-BIT TIMER
PRESCALER SELECT
157.28 mS
314.57 mS
629.14 mS
CLEAR
19.66 mS
39.32 mS
78.64 mS
Publication Release Date: April 28, 2008
1.25 S
2.50 S
128
256
16
32
64
2
4
8
INTERNAL
RESET
Revision A8