T89C51CC02 Atmel, T89C51CC02 Datasheet - Page 65

• Manufacturer Part Number: T89C51CC02
• Description: 8-Bit MCU
• Manufacturer: Atmel

14.2. WatchDog Programming
The three lower bits (S0, S1, S2) located into WDTPRG register permits to program the WDT duration.
To compute WD Time-Out, the following formula is applied:
Note: Svalue represents the decimal value of (S2 S1 S0)
Find Hereafter computed Time-Out value for Fosc
Rev.A - May 17, 2001
S2
0
0
0
0
1
1
1
1
S2
0
0
0
0
1
1
1
1
S1
0
0
1
1
0
0
1
1
FTime Out
S1
0
0
1
1
0
0
1
1
S0
Table 19. Time-Out Computation
0
1
0
1
0
1
0
1
Table 18. Machine Cycle Count
–
Preliminary
=
S0
0
1
0
1
0
1
0
1
------------------------------------------------------------ -
12
XTAL
Fosc=12MHz
131.07 ms
262.14 ms
524.29 ms
16.38 ms
32.77 ms
65.54 ms
1.05 s
2.10 s
= 12MHz
2
14
F
XTAL
2
Svalue
Machine Cycle Count
Fosc=16MHz
196.56 ms
393.12 ms
786.24 ms
12.28 ms
24.57 ms
49.14 ms
98.28 ms
2
2
2
2
2
2
2
2
1.57 s
–
14
15
16
17
18
19
20
21
1
- 1
- 1
- 1
- 1
- 1
- 1
- 1
- 1
T89C51CC02
Fosc=20MHz
157.28 ms
314.56 ms
629.12 ms
19.66 ms
39.32 ms
78.64 ms
9.82 ms
1.25 ms
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