T89C5115 ATMEL Corporation, T89C5115 Datasheet - Page 63

• Manufacturer Part Number: T89C5115
• Description: Low Pin Count 8-bit MCU with A/D Converter and 16-Kbytes of Flash Memory
• Manufacturer: ATMEL Corporation

WatchDog Programming
4128A–8051–04/02
The three lower bits (S0, S1, S2) located into WDTPRG register permit to program the
WDT duration.
Table 43. Machine Cycle Count
To compute WD Time-Out, the following formula is applied:
Note:
The following table indicates the computed Time-Out value for Fosc
mode
Table 44. Time-Out Computation
S2
0
0
0
0
1
1
1
1
S2
0
0
0
0
1
1
1
1
Svalue represents the decimal value of (S2 S1 S0)
S1
0
0
1
1
0
0
1
1
S1
0
0
1
1
0
0
1
1
FTime Out
S0
0
1
0
1
0
1
0
1
–
S0
=
0
1
0
1
0
1
0
1
Fosc = 12 MHz
------------------------------------------------------------------ -
12
131.07 ms
262.14 ms
524.29 ms
16.38 ms
32.77 ms
65.54 ms
1.05 sec
2.10 sec
×
(
(
2
14
F
×
wd
2
Svalue
Fosc = 16 MHz
Machine Cycle Count
196.56 ms
393.12 ms
786.24 ms
) 1
12.28 ms
24.57 ms
49.14 ms
98.28 ms
1.57 s
–
)
2
2
2
2
2
2
2
2
14
15
17
18
19
20
21
16
- 1
- 1
- 1
- 1
- 1
- 1
- 1
- 1
XTAL
T89C5115
= 12 MHz in X1
Fosc = 20 MHz
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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