ATmega325 Atmel Corporation, ATmega325 Datasheet - Page 56

• Manufacturer Part Number: ATmega325
• Manufacturer: Atmel Corporation

Specifications of ATmega325

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

13.2
13.2.1
2570N–AVR–05/11
Register Description
EICRA – External Interrupt Control Register A
Figure 13-1. Pin Change Interrupt
The External Interrupt Control Register A contains control bits for interrupt sense control.
• Bit 1, 0 – ISC01, ISC00: Interrupt Sense Control 0 Bit 1 and Bit 0
The External Interrupt 0 is activated by the external pin INT0 if the SREG I-flag and the corre-
sponding interrupt mask are set. The level and edges on the external INT0 pin that activate the
interrupt are defined in
edges. If edge or toggle interrupt is selected, pulses that last longer than one clock period will
generate an interrupt. Shorter pulses are not guaranteed to generate an interrupt. If low level
interrupt is selected, the low level must be held until the completion of the currently executing
instruction to generate an interrupt.
Table 13-1.
Bit
(0x69)
Read/Write
Initial Value
ISC01
0
0
1
1
pcint_setflag
pcint_in_(n)
PCINT(n)
pcint_syn
pin_sync
ISC00
pin_lat
Interrupt 0 Sense Control
PCINT(0)
PCIF
R
7
–
0
0
1
0
1
clk
clk
Description
The low level of INT0 generates an interrupt request.
Any logical change on INT0 generates an interrupt request.
The falling edge of INT0 generates an interrupt request.
The rising edge of INT0 generates an interrupt request.
LE
R
6
–
0
Table
pin_lat
D
13-1. The value on the INT0 pin is sampled before detecting
R
5
–
0
Q
pin_sync
PCINT(0) in PCMSK(x)
4
–
R
0
ATmega325/3250/645/6450
pcint_in_(0)
R
3
–
0
0
x
clk
R
2
–
0
pcint_syn
ISC01
R/W
1
0
pcint_setflag
ISC00
R/W
0
0
EICRA
PCIF
56