AT32UC3A0128-ALUR Atmel, AT32UC3A0128-ALUR Datasheet - Page 95

• Manufacturer Part Number: AT32UC3A0128-ALUR
• Description: MCU AVR32 128K FLASH 144LQFP
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3A0128-ALUR

• Core Processor: AVR
• Core Size: 32-Bit
• Speed: 66MHz
• Connectivity: EBI/EMI, Ethernet, I²C, SPI, SSC, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 109
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K 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: 144-LQFP
• Package: 144LQFP
• Device Core: AVR32
• Family Name: AT32
• Maximum Speed: 66 MHz
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 69
• Interface Type: Ethernet/I2S/JTAG/SPI/TWI/USART
• Number Of Timers: 3
• For Use With: ATEVK1105 - KIT EVAL FOR AT32UC3A0ATAVRONEKIT - KIT AVR/AVR32 DEBUGGER/PROGRMMR770-1008 - ISP 4PORT ATMEL AVR32 MCU SPIATEVK1100 - KIT DEV/EVAL FOR AVR32 AT32UC3A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

15.5
32058J–AVR32–04/11
Functional Description
The WDT is enabled by writing the EN bit in the CTRL register to one. This also enables the RC
clock for the prescaler. The PSEL bitfield in the same register selects the watchdog timeout
period:
The next timeout period will begin as soon as the watchdog reset has occured and count down
during the reset sequence. Care must be taken when selecting the PSEL value so that the time-
out period is greater than the startup time of the chip, otherwise a watchdog reset can reset the
chip before any code has been run.
To avoid accidental disabling of the watchdog, the CTRL register must be written twice, first with
the KEY field set to 0x55, then 0xAA without changing the other bitfields. Failure to do so will
cause the write operation to be ignored, and CTRL does not change value.
The CLR register must be written with any value with regular intervals shorter than the watchdog
timeout period. Otherwise, the device will receive a soft reset, and the code will start executing
from the boot vector.
When the WDT is enabled, it is not possible to enter Static mode. Attempting to do so will result
in entering Shutdown mode, leaving the WDT operational.
T
WDT
= 2
(PSEL+1)
/ f
RC
AT32UC3A
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