Datasheet

62
7799D–AVR–11/10
ATmega8U2/16U2/32U2
Table 10-8. Watchdog Timer Prescale Select, DIV = 5 (CLKwdt = CLK128 / 11)
WDP3 WDP2 WDP1 WDP0
Number of WDT Oscillator
Cycles before 1st time-out
(Early warning)
Early warning Typical
Time-out at
V
CC
= 5.0V
Watchdog
Reset/Interrupt Typical
Time-out at
V
CC
= 5.0V
0 0 0 0 2K (2048) cycles 88 ms 176 ms
0 0 0 1 4K (4096) cycles 176 ms 352 ms
0 0 1 0 8K (8192) cycles 352 ms 704 ms
0 0 1 1 16K (16384) cycles 704 ms 1.4 s
0 1 0 0 32K (32768) cycles 1.4 s 2.8 s
0 1 0 1 64K (65536) cycles 2.8 s 5.6 s
0 1 1 0 128K (131072) cycles 5.6 s 11.2 s
0 1 1 1 256K (262144) cycles 11.2 s 22.5 s
1 0 0 0 512K (524288) cycles 22.5 s 45 s
1 0 0 1 1024K (1048576) cycles 45s 90 s
1010
Reserved
1011
1100
1101
1110
1111
Table 10-9. Watchdog Timer Prescale Select, DIV = 6(CLKwdt = CLK128 / 13)
WDP3 WDP2 WDP1 WDP0
Number of WDT Oscillator
Cycles before 1st time-out
(Early warning)
Early warning Typical
Time-out at
V
CC
= 5.0V
Watchdog
Reset/Interrupt Typical
Time-out at
V
CC
= 5.0V
0 0 0 0 2K (2048) cycles 104 ms 208 ms
0 0 0 1 4K (4096) cycles 208 ms 416 ms
0 0 1 0 8K (8192) cycles 416 ms 832 ms
0 0 1 1 16K (16384) cycles 832 ms 1.64 s
0 1 0 0 32K (32768) cycles 1.6 s 3.3 s
0 1 0 1 64K (65536) cycles 3.3 s 6.6 s
0 1 1 0 128K (131072) cycles 6.6 s 13.3 s
0 1 1 1 256K (262144) cycles 13.3 s 26.6 s
1 0 0 0 512K (524288) cycles 26.6 s 53.2 s
1 0 0 1 1024K (1048576) cycles 53.2 s 106.4 s