ATMEGA32A-MU Atmel, ATMEGA32A-MU Datasheet - Page 40

• Manufacturer Part Number: ATMEGA32A-MU
• Description: MCU AVR 32K FLASH 16MHZ 44-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32A-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VQFN Exposed Pad
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: 2-Wire, SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AVR MEGA
• No. Of I/o's: 32
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.2.2
10.2.3
8155C–AVR–02/11
External Reset
Brown-out Detection
Figure 10-3. MCU Start-up, RESET Extended Externally
An External Reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
reset, even if the clock is not running. Shorter pulses are not guaranteed to generate a reset.
When the applied signal reaches the Reset Threshold Voltage – V
delay counter starts the MCU after the Time-out period t
Figure 10-4. External Reset During Operation
ATmega32A has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
ing operation by comparing it to a fixed trigger level. The trigger level for the BOD can be
selected by the fuse BODLEVEL to be 2.7V (BODLEVEL unprogrammed), or 4.0V (BODLEVEL
programmed). 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
The BOD circuit can be enabled/disabled by the fuse BODEN. When the BOD is enabled
(BODEN programmed), and V
5), the Brown-out Reset is immediately activated. When V
(V
expired.
The BOD circuit will only detect a drop in V
ger than t
BOT
BOT+
- V
in
INTERNAL
TIME-OUT
HYST
BOD
Figure
RESET
RESET
V
/2.
CC
given in
CC
10-5), the delay counter starts the MCU after the Time-out period t
“System and Reset Characteristics” on page
“System and Reset Characteristics” on page
V
CC
POT
decreases to a value below the trigger level (V
CC
if the voltage stays below the trigger level for lon-
V
RST
t
TOUT
TOUT
CC
has expired.
BOT+
increases above the trigger level
= V
RST
299.
BOT
– on its positive edge, the
ATmega32A
+ V
299) will generate a
HYST
BOT-
/2 and V
in
CC
Figure 10-
level dur-
TOUT
BOT-
has
40
=