ATMEGA644P-A15MZ Atmel, ATMEGA644P-A15MZ Datasheet - Page 52

• Manufacturer Part Number: ATMEGA644P-A15MZ
• Description: MCU AVR 64KB FLASH 16MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-A15MZ

• Package / Case: 44-VQFN Exposed Pad
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 32
• Eeprom Size: 2K x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Program Memory Size: 64KB (64K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: I²C, SPI, UART/USART
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.0.5
9.0.6
52
ATmega164P/324P/644P
Brown-out Detection
Watchdog Reset
Figure 9-2.
ATmega164P/324P/644P has an On-chip Brown-out Detection (BOD) circuit for monitoring the
V
can be selected by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure spike
free Brown-out Detection. The hysteresis on the detection level should be interpreted as V
V
When the BOD is enabled, and V
9-3 on page
trigger level (V
Time-out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 9-3.
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On
the falling edge of this pulse, the delay timer starts counting the Time-out period t
page 60
CC
BOT
level during operation by comparing it to a fixed trigger level. The trigger level for the BOD
+ V
HYST
for details on operation of the Watchdog Timer.
BOD
CC
52), the Brown-out Reset is immediately activated. When V
/2 and V
given in
External Reset During Operation
Brown-out Reset During Operation
INTERNAL
TIME-OUT
BOT+
TOUT
RESET
RESET
V
in
CC
BOT-
has expired.
“System and Reset Characteristics” on page
Figure 9-3 on page
= V
BOT
- V
CC
HYST
decreases to a value below the trigger level (V
V
BOT-
/2.
CC
52), the delay counter starts the MCU after the
if the voltage stays below the trigger level for lon-
V
t
TOUT
BOT+
332.
CC
increases above the
TOUT
7674F–AVR–09/09
BOT-
. Refer to
in
Figure
BOT+
=