at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 111

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

17. Watchdog Timer (WDT)
17.1
17.2
Figure 17-1. Watchdog Timer Block Diagram
6384B–ATARM–15-Dec-08
Overview
Block Diagram
WDRSTT
WDT_CR
read WDT_SR
or
reset
write WDT_MR
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.
WDT_MR
WDD
WDERR
<= WDD
set
reset
reload
WDT_MR
WDV
12-bit Down
1
WDUNF
Counter
Current
Value
= 0
reset
set
0
AT91SAM9G20 Preliminary
1/128
reload
WDRSTEN
WDT_MR
WDT_MR
WDFIEN
SLCK
(to Reset Controller)
wdt_int
wdt_fault
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