ATMEGA645-16MU Atmel, ATMEGA645-16MU Datasheet - Page 55

• Manufacturer Part Number: ATMEGA645-16MU
• Description: IC AVR MCU FLASH 64K 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA645-16MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K 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: 64-MLF®, 64-QFN
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, UART, USI
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• 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
• Package: 64MLF EP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12. External Interrupts
12.1
2570M–AVR–04/11
Pin Change Interrupt Timing
The External Interrupts are triggered by the INT0 pin or any of the PCINT30..0 pins. Observe
that, if enabled, the interrupts will trigger even if the INT0 or PCINT30..0 pins are configured as
outputs. This feature provides a way of generating a software interrupt. The pin change interrupt
PCI1 will trigger if any enabled PCINT15..8 pin toggles. Pin change interrupts PCI0 will trigger if
any enabled PCINT7..0 pin toggles. The PCMSK3, PCMSK2, PCMSK1, and PCMSK0 Registers
control which pins contribute to the pin change interrupts. Pin change interrupts on PCINT30..0
are detected asynchronously. This implies that these interrupts can be used for waking the part
also from sleep modes other than Idle mode.
The INT0 interrupts can be triggered by a falling or rising edge or a low level. This is set up as
indicated in the specification for the External Interrupt Control Register A – EICRA. When the
INT0 interrupt is enabled and is configured as level triggered, the interrupt will trigger as long as
the pin is held low. Note that recognition of falling or rising edge interrupts on INT0 requires the
presence of an I/O clock, described in
level interrupt on INT0 is detected asynchronously. This implies that this interrupt can be used
for waking the part also from sleep modes other than Idle mode. The I/O clock is halted in all
sleep modes except Idle mode.
Note that if a level triggered interrupt is used for wake-up from Power-down, the required level
must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If
the level disappears before the end of the Start-up Time, the MCU will still wake up, but no inter-
rupt will be generated. The start-up time is defined by the SUT and CKSEL Fuses as described
in
An example of timing of a pin change interrupt is shown in
“System Clock and Clock Options” on page
“Clock Systems and their Distribution” on page
ATmega325/3250/645/6450
26.
Figure
12-1.
26. Low
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