ATMEGA3250P-20AUR Atmel, ATMEGA3250P-20AUR Datasheet - Page 58

• Manufacturer Part Number: ATMEGA3250P-20AUR
• Description: MCU AVR 32K FLASH 20MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250P-20AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• 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: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12. External Interrupts
12.1
8023F–AVR–07/09
Overview
The External Interrupts are triggered by the INT0 pin or any of the PCINT30:0 pins
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
isters 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 wak-
ing 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
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
page
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
Notes:
”System Clock and Clock Options” on page
29. Low level interrupt on INT0 is detected asynchronously. This implies that this interrupt
1. PCMSK3 and PCMSK2 are only present in ATmega3250P.
2. PCINT30:16 are only present in ATmega3250P. Only PCINT15:0 are present in ATmega325P.
See
”Pin Configurations” on page 2
”EICRA – External Interrupt Control Register A” on page
and
29.
”Register Description” on page 59
(1)
, PCMSK2
”Clock Systems and their Distribution” on
ATmega325P/3250P
(1)
, PCMSK1, and PCMSK0 Reg-
for details.
(2)
. Observe
59.
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