AT91SAM7S321-AU Atmel, AT91SAM7S321-AU Datasheet - Page 111

• Manufacturer Part Number: AT91SAM7S321-AU
• Description: IC ARM7 MCU FLASH 32K 64LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S321-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-LQFP
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 8 KB
• Interface Type: I2C, I2S, SPI, SSC, TWI, UART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 10 bit
• Operating Supply Voltage: 1.8 V to 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, KSK-AT91SAM7S-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7S-EK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AT91SAM7xxxx
• No. Of I/o's: 32
• Ram Memory Size: 8KB
• Cpu Speed: 55MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7S-EK - KIT EVAL FOR ARM AT91SAM7S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

17. Watchdog Timer (WDT)
17.1
17.2
Figure 17-1. Watchdog Timer Block Diagram
6175G–ATARM–22-Nov-06
Overview
Block Diagram
WDT_CR
WDRSTT
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
AT91SAM7S Series Preliminary
1/128
reload
WDRSTEN
WDT_MR
WDT_MR
WDFIEN
SLCK
(to Reset Controller)
wdt_int
wdt_fault
111