T89C5115_08 ATMEL [ATMEL Corporation], T89C5115_08 Datasheet - Page 68

• Manufacturer Part Number: T89C5115_08
• Description: Low Pin Count 8-bit Microcontroller with A/D Converter and 16 KBytes Flash Memory
• Manufacturer: ATMEL [ATMEL Corporation]

Watchdog Programming
68
AT89C5115
The three lower bits (S0, S1, S2) located into WDTPRG register permit to program the
WDT duration.
Table 49. Machine Cycle Count
To compute WD Timeout, the following formula is applied:
Note:
Find Hereafter computed Timeout values for f
Table 50. Timeout 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)
FTime Out
S1
0
0
1
1
0
0
1
1
–
S1
0
0
1
1
0
0
1
1
=
---------------------------------------------------------------------------- -
6 2
×
S0
0
1
0
1
0
1
0
1
WDX2
S0
0
1
0
1
0
1
0
1
∧
X2
f
F
OSC
131.07 ms
262.14 ms
524.29 ms
osc
16.38 ms
32.77 ms
65.54 ms
(
1.05 s
2.10 s
2
=12 MHz
14
OSC
×
2
Svalue
XTAL = 12 MHz in X1 mode
)
f
Machine Cycle Count
OSC
196.56 ms
393.12 ms
786.24 ms
12.28 ms
24.57 ms
49.14 ms
98.28 ms
1.57 s
=16MHz
2
2
2
2
2
2
2
2
14
15
17
18
19
20
21
16
- 1
- 1
- 1
- 1
- 1
- 1
- 1
- 1
f
4128G–8051–02/08
OSC
157.28 ms
314.56 ms
629.12 ms
19.66 ms
39.32 ms
78.64 ms
9.82 ms
1.25 s
=20 MHz