ATtiny20 Atmel Corporation, ATtiny20 Datasheet - Page 40

• Manufacturer Part Number: ATtiny20
• Manufacturer: Atmel Corporation

Specifications of ATtiny20

• Flash (kbytes): 2 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 12 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 5
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 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: Yes
• Crypto Engine: No
• Sram (kbytes): 0.12
• Self Program Memory: NO
• 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: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

9.2.1
9.2.2
40
ATtiny20
Low Level Interrupt
Pin Change Interrupt Timing
A low level interrupt on INT0 is detected asynchronously. This means that the interrupt source
can be used for waking the part also from sleep modes other than Idle (the I/O clock is halted in
all sleep modes except Idle).
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 as described in
If the low level on the interrupt pin is removed before the device has woken up then program
execution will not be diverted to the interrupt service routine but continue from the instruction fol-
lowing the SLEEP command.
A timing example of a pin change interrupt is shown in
Figure 9-1.
pcint_setflag
pcint_in_(0)
PCINT(0)
pcint_syn
pin_sync
pin_lat
PCINT(0)
PCIF
clk
clk
Timing of pin change interrupts
LE
pin_lat
D
Q
pin_sync
PCINT(0) in PCMSK(x)
pcint_in_(0)
0
x
clk
Figure
9-1.
“Clock System” on page
pcint_syn
pcint_setflag
8235B–AVR–04/11
PCIF
18.