ATMEGA16M1-MU Atmel, ATMEGA16M1-MU Datasheet - Page 46

• Manufacturer Part Number: ATMEGA16M1-MU
• Description: IC MCU AVR 16K FLASH 32VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16M1-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: CAN, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -

10.4
10.4.1
10.4.2
46
Watchdog Timer
ATmega16M1/32M1/64M1
Features
Overview
Thus, when the BOD is not enabled, after setting the ACBG bit or enabling the ADC or the DAC,
the user must always allow the reference to start up before the output from the Analog Compar-
ator or ADC or DAC is used. To reduce power consumption in Power-down mode, the user can
avoid the three conditions above to ensure that the reference is turned off before entering
Power-down mode.
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The ATmega16M1/32M1/64M1 has an Enhanced Watchdog Timer (WDT). The WDT is a timer
counting cycles of a separate on-chip 128kHz oscillator. The WDT gives an interrupt or a system
reset when the counter reaches a given time-out value. In normal operation mode, it is required
that the system uses the WDR - Watchdog Timer Reset - instruction to restart the counter before
the time-out value is reached. If the system doesn't restart the counter, an interrupt or system
reset will be issued.
Figure 10-7. Watchdog Timer
In Interrupt mode, the WDT gives an interrupt when the timer expires. This interrupt can be used
to wake the device from sleep-modes, and also as a general system timer. One example is to
limit the maximum time allowed for certain operations, giving an interrupt when the operation
has run longer than expected. In System Reset mode, the WDT gives a reset when the timer
expires. This is typically used to prevent system hang-up in case of runaway code. The third
mode, Interrupt and System Reset mode, combines the other two modes by first giving an inter-
rupt and then switch to System Reset mode. This mode will for instance allow a safe shutdown
by saving critical parameters before a system reset.
Clocked from separate On-chip Oscillator
3 Operating modes
Selectable Time-out period from 16ms to 8s
Possible Hardware fuse Watchdog always on (WDTON) for fail-safe mode
– Interrupt
– System Reset
– Interrupt and System Reset
OSCILLATOR
WDP3
128kHz
WDIF
WDIE
INTERRUPT
MCU RESET
8209D–AVR–11/10