257
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
Figure 13-6. Watchdog Reset
13.4.5
Reset State Priorities
The Reset State Manager manages the following priorities between the different reset sources,
given in descending order:
• General Reset
• Backup Reset
• Watchdog Reset
• Software Reset
• User Reset
Particular cases are listed below:
• When in User Reset:
– A watchdog event is impossible because the Watchdog Timer is being reset by the
proc_nreset signal.
– A software reset is impossible, since the processor reset is being activated.
• When in Software Reset:
– A watchdog event has priority over the current state.
– The NRST has no effect.
• When in Watchdog Reset:
– The processor reset is active and so a Software Reset cannot be programmed.
– 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
= 2 cycles
Any
Freq.
RSTTYP
Any
XXX
0x2 = Watchdog Reset
Summary of Contents for SAM4S Series
Page 44: ...44 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 412: ...412 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 1105: ...1105 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 1143: ...1143 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 4 64 lead LQFP Package Drawing ...
Page 1145: ...1145 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 5 64 lead QFN Package Drawing ...