ATtiny20 Atmel Corporation, ATtiny20 Datasheet - Page 127

• 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

15.13.4
8235B–AVR–04/11
ADCSRB – ADC Control and Status Register B
• Bits 2:0 – ADPS[2:0]: ADC Prescaler Select Bits
These bits determine the division factor between the system clock frequency and the input clock
to the ADC.
Table 15-5.
• Bit 7 – VDEN
This bit is reserved for QTouch, always write as zero.
• Bit 6 – VDPD
This bit is reserved for QTouch, always write as zero.
• Bits 5:4 – Res: Reserved Bits
These are reserved bits. For compatibility with future devices always write these bits to zero.
• Bit 3 – ADLAR: ADC Left Adjust Result
The ADLAR bit affects the presentation of the ADC conversion result in the ADC Data Register.
Write one to ADLAR to left adjust the result. Otherwise, the result is right adjusted. Changing the
ADLAR bit will affect the ADC Data Register immediately, regardless of any ongoing conver-
sions. For a comple the description of this bit, see
page
• Bits 2:0 – ADTS[2:0] : ADC Auto Trigger Source
If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger
an ADC conversion. If ADATE is cleared, the ADTS[2:0] settings will have no effect. A conver-
sion will be triggered by the rising edge of the selected Interrupt Flag. Note that switching from a
trigger source that is cleared to a trigger source that is set, will generate a positive edge on the
Bit
0x11
Read/Write
Initial Value
125.
ADPS2
0
0
0
0
1
1
1
1
ADC Prescaler Selections
VDEN
R/W
7
0
VDPD
R/W
ADPS1
6
0
0
0
1
1
0
0
1
1
R
5
–
0
R
4
–
0
ADPS0
0
1
0
1
0
1
0
1
ADLAR
“ADCL and ADCH – ADC Data Register” on
R/W
3
0
ADTS2
R/W
2
0
ADTS1
Division Factor
R/W
1
0
128
16
32
64
2
2
4
8
ADTS0
ATtiny20
R/W
0
0
ADCSRB
127