Datasheet

119
SAM9G25 [DATASHEET]
11032C–ATARM–25-Jan-13
Figure 14-8. Watchdog Reset
14.4.5 Reset State Priorities
The Reset State Manager manages the following priorities between the different reset sources, given in descending
order:
z Backup Reset
z Wake-up Reset
z User Reset
z Watchdog Reset
z Software Reset
Particular cases are listed below:
z When in User Reset:
z A watchdog event is impossible because the Watchdog Timer is being reset by the proc_nreset signal.
z A software reset is impossible, since the processor reset is being activated.
z When in Software Reset:
z A watchdog event has priority over the current state.
z The NRST has no effect.
z When in Watchdog Reset:
z The processor reset is active and so a Software Reset cannot be programmed.
z A User Reset cannot be entered.
Only if
WDRPROC = 0
SLCK
periph_nreset
proc_nreset
wd_fault
NRST
(nrst_out)
EXTERNAL RESET LENGTH
8 cycles (ERSTL=2)
MCK
Processor Startup
= 3 cycles
Any
Freq.
RSTTYP
Any XXX
0x2 = Watchdog Reset