ATtiny261 Atmel Corporation, ATtiny261 Datasheet - Page 42

• Manufacturer Part Number: ATtiny261
• Manufacturer: Atmel Corporation

Specifications of ATtiny261

• Flash (kbytes): 2 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 4
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• 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
• Eeprom (bytes): 128
• 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: 2
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.1
8.1.1
42
Reset Sources
ATtiny261/461/861
Power-on Reset
The ATtiny261/461/861 has four sources of reset:
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level
is defined in
V
well as to detect a failure in supply voltage.
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the
Power-on Reset threshold voltage invokes the delay counter, which determines how long the
device is kept in RESET after V
when V
Figure 8-2.
Figure 8-3.
CC
• Power-on Reset. The MCU is reset when the supply voltage is below the Power-on Reset
• External Reset. The MCU is reset when a low level is present on the RESET pin for longer
• Watchdog Reset. The MCU is reset when the Watchdog Timer period expires and the
• Brown-out Reset. The MCU is reset when the supply voltage V
threshold (V
than the minimum pulse length.
Watchdog is enabled.
Reset threshold (V
is below the detection level. The POR circuit can be used to trigger the Start-up Reset, as
INTERNAL
INTERNAL
TIME-OUT
TIME-OUT
CC
RESET
RESET
RESET
RESET
V
V
decreases below the detection level.
CC
CC
“System and Reset Characteristics” on page
MCU Start-up, RESET Tied to V
MCU Start-up, RESET Extended Externally
POT
).
BOT
) and the Brown-out Detector is enabled.
V
V
V
POT
POT
RST
CC
t
TOUT
rise. The RESET signal is activated again, without any delay,
CC
V
RST
t
TOUT
190. The POR is activated whenever
CC
is below the Brown-out
2588E–AVR–08/10