at75c220 ATMEL Corporation, at75c220 Datasheet - Page 143

• Manufacturer Part Number: at75c220
• Description: Smart Internet Appliance Processor Siap
• Manufacturer: ATMEL Corporation

WD Status Register
Name:
Access:
•
WD Enabling Sequence
To enable the Watchdog Timer the sequence is as follows:
1. Disable the Watchdog by clearing the bit WDEN:
2. Initialize the WD Clock Mode Register:
3. Restart the timer:
4. Enable the watchdog:
WDOVF: Watchdog Overflow
0 = No watchdog overflow.
1 = A watchdog overflow has occurred since the last restart of the watchdog counter or since internal or external reset.
Write 0x2340 to WD_OMR
This step is unnecessary if the WD is already disabled
(reset state).
Write 0x373C to WD_CMR
(HPCV = 15 and WDCLKS = MCK/8)
Write 0xC071 to WD_CR
Write 0x2345 to WD_OMR (interrupt enabled)
31
23
15
–
–
–
7
–
WD_SR
Read-only
30
22
14
–
–
–
6
–
29
21
13
–
–
–
5
–
28
20
12
–
–
–
4
–
27
19
11
–
–
–
3
–
26
18
10
–
–
–
2
–
25
17
–
–
9
–
1
–
WDOVF
24
16
–
–
8
–
0
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