.
Table 28. Watchdog Timer Prescale Select
Number of WDT Oscillator
Typical Time-out at
VCC = 5.0V
WDP3 WDP2 WDP1 WDP0
Cycles
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2K (2048) cycles
16 ms
32 ms
64 ms
0.125 s
0.25 s
0.5 s
4K (4096) cycles
8K (8192) cycles
16K (16384) cycles
32K (32768) cycles
64K (65536) cycles
128K (131072) cycles
256K (262144) cycles
512K (524288) cycles
1024K (1048576) cycles
1.0 s
2.0 s
4.0 s
8.0 s
Reserved
68
ATmega640/1280/1281/2560/2561
2549A–AVR–03/05