AT89C5115 Atmel Corporation, AT89C5115 Datasheet - Page 68

• Manufacturer Part Number: AT89C5115
• Manufacturer: Atmel Corporation

Specifications of AT89C5115

• Flash (kbytes): 16 Kbytes
• Max. Operating Frequency: 40 MHz
• Cpu: 8051-12C
• Max I/o Pins: 20
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 62.5
• Sram (kbytes): 0.5
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

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