ATtiny20 Atmel Corporation, ATtiny20 Datasheet - Page 26

• 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

7.1.2
7.1.3
7.1.4
7.2
26
Software BOD Disable
ATtiny20
ADC Noise Reduction Mode
Power-down Mode
Standby Mode
analog comparator can be powered down by setting the ACD bit in
tor Control and Status Register” on page
If the ADC is enabled, a conversion starts automatically when this mode is entered.
When bits SM[2:0] are written to 001, the SLEEP instruction makes the MCU enter ADC Noise
Reduction mode, stopping the CPU but allowing the ADC, the external interrupts, TWI and the
watchdog to continue operating (if enabled). This sleep mode halts clk
while allowing the other clocks to run.
This mode improves the noise environment for the ADC, enabling higher resolution measure-
ments. If the ADC is enabled, a conversion starts automatically when this mode is entered.
When bits SM[2:0] are written to 010, the SLEEP instruction makes the MCU enter Power-down
mode. In this mode, the oscillator is stopped, while the external interrupts, TWI and the watch-
dog continue operating (if enabled). Only a watchdog reset, an external level interrupt on INT0, a
pin change interrupt, or a TWI slave interrupt can wake up the MCU. This sleep mode halts all
generated clocks, allowing operation of asynchronous modules only.
When bits SM[2:0] are written to 100, the SLEEP instruction makes the MCU enter Standby
mode. This mode is identical to Power-down with the exception that the oscillator is kept run-
ning. This reduces wake-up time, because the oscillator is already running and doesn't need to
be started up.
When the Brown-out Detector (BOD) is enabled by BODLEVEL fuses (see
165), the BOD is actively monitoring the supply voltage during a sleep period. In some devices it
is possible to save power by disabling the BOD by software in Power-Down and Stand-By sleep
modes. The sleep mode power consumption will then be at the same level as when BOD is glob-
ally disabled by fuses.
If BOD is disabled by software, the BOD function is turned off immediately after entering the
sleep mode. Upon wake-up from sleep, BOD is automatically enabled again. This ensures safe
operation in case the V
When the BOD has been disabled, the wake-up time from sleep mode will be approximately
60µs to ensure that the BOD is working correctly before the MCU continues executing code.
BOD disable is controlled by the BODS (BOD Sleep) bit of MCU Control Register, see
– MCU Control Register” on page
Stand-By, while writing a zero keeps the BOD active. The default setting is zero, i.e. BOD active.
Writing to the BODS bit is controlled by a timed sequence, see
ter” on page
28.
CC
level has dropped during the sleep period.
28. Writing this bit to one turns off BOD in Power-Down and
109. This will reduce power consumption in idle mode.
“MCUCR – MCU Control Regis-
“ACSRA – Analog Compara-
I/O
, clk
Table 19-5 on page
CPU
8235B–AVR–04/11
, and clk
“MCUCR
NVM
,