attiny167-esxz ATMEL Corporation, attiny167-esxz Datasheet - Page 56

• Manufacturer Part Number: attiny167-esxz
• Description: 8-bit Avr 8-bit Microcontroller Microcontroller With 16k Bytes In-system Programmable Flash And Lin Controller
• Manufacturer: ATMEL Corporation

56
ATtiny167
• Bit 3 - WDE: Watchdog System Reset Enable
WDE is overridden by WDRF in MCUSR. This means that WDE is always set when WDRF is
set. To clear WDE, WDRF must be cleared first. This feature ensures multiple resets during con-
ditions causing failure, and a safe start-up after the failure.
• Bit 5, 2..0 - WDP3..0: Watchdog Timer Prescaler 3, 2, 1 and 0
The WDP3..0 bits determine the Watchdog Timer prescaling when the Watchdog Timer is run-
ning. The different prescaling values and their corresponding time-out periods are shown in
Table 6-2 on page
Table 6-2.
WDP3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
WDP2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Watchdog Timer Prescale Select
56.
WDP1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
WDT Oscillator Cycles
1024K (1048576) cycles
128K (131072) cycles
256K (262144) cycles
512K (524288) cycles
16K (16384) cycles
32K (32768) cycles
64K (65536) cycles
2K (2048) cycles
4K (4096) cycles
8K (8192) cycles
Number of
Reserved
Typical Time-out
at Vcc = 5.0V
0.125 s
16 ms
32 ms
64 ms
0.25 s
0.5 s
1.0 s
2.0 s
4.0 s
8.0 s
7728A–AUTO–07/08