AT91SAM7S256D-AU Atmel, AT91SAM7S256D-AU Datasheet - Page 89

• Manufacturer Part Number: AT91SAM7S256D-AU
• Description: ARM Microcontrollers - MCU 256K Flash SRAM 64K ARM based MCU
• Manufacturer: Atmel
• Series: SAM7S256r

Specifications of AT91SAM7S256D-AU

• Rohs: yes
• Core: ARM
• Processor Series: AT91SAM
• Data Bus Width: 16 bit/32 bit
• Maximum Clock Frequency: 55 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 64 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 3 V to 3.6 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-64
• Mounting Style: SMD/SMT
• Interface Type: 2-Wire, I2S, SPI, USART
• Length: 7 mm

16. Watchdog Timer (WDT)
16.1
16.2
Figure 16-1. Watchdog Timer Block Diagram
Overview
The Watchdog Timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. It fea-
tures 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.
Block Diagram
WDT_CR
WDRSTT
read WDT_SR
or
reset
write WDT_MR
WDT_MR
WDD
WDERR
<= WDD
set
reset
reload
WDT_MR
WDV
12-bit Down
1
WDUNF
Counter
Current
Value
= 0
reset
set
0
1/128
reload
WDRSTEN
SAM7S Series [DATASHEET]
WDT_MR
WDT_MR
WDFIEN
SLCK
(to Reset Controller)
wdt_int
6175M–ATARM–26-Oct-12
wdt_fault
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