ATtiny84 Atmel Corporation, ATtiny84 Datasheet - Page 40

• Manufacturer Part Number: ATtiny84
• Manufacturer: Atmel Corporation

Specifications of ATtiny84

• Flash (kbytes): 8 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 6
• Hardware Qtouch Acquisition: No
• 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): 0.5
• Eeprom (bytes): 512
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.2
8.2.1
40
Reset Sources
ATtiny24/44/84
Power-on Reset
The ATtiny24/44/84 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 when RESET function is enabled.
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
177. The POR is activated whenever
CC
is below the Brown-out
8006K–AVR–10/10