SAM7X128_14 Datasheet, PDF (82/662 Pages) ATMEL Corporation – ARM-based Flash MCU

16. Watchdog Timer (WDT)
16.1 Overview
The Watchdog Timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. It features a
12-bit down counter that allows a watchdog period of up to 16 seconds (slow clock at 32.768 kHz). It can generate a
general reset or a processor reset only. In addition, it can be stopped while the processor is in debug mode or idle mode.
16.2 Block Diagram
Figure 16-1. Watchdog Timer Block Diagram
write WDT_MR
WDT_CR
WDRSTT
WDT_MR
WDV
reload
1
0
WDT_MR
WDD
<= WDD
read WDT_SR
or
reset
set
WDERR
reset
12-bit Down
Counter
Current
Value
=0
set
WDUNF
reset
reload
1/128
SLCK
WDT_MR
WDRSTEN
wdt_fault
(to Reset Controller)
wdt_int
WDFIEN
WDT_MR
SAM7X Series [DATASHEET] 82
6120K–ATARM–11-Feb-14