ATTINY261-20MUR Atmel, ATTINY261-20MUR Datasheet - Page 146

• Manufacturer Part Number: ATTINY261-20MUR
• Description: IC MCU AVR 2K FLASH 20MHZ 32QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY261-20MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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ATtiny261/461/861
Figure 15-3. ADC Prescaler
When initiating a single ended conversion by setting the ADSC bit in ADCSRA, the conversion
starts at the following rising edge of the ADC clock cycle.
A normal conversion takes 13 ADC clock cycles. The first conversion after the ADC is switched
on (ADEN in ADCSRA is set) takes 25 ADC clock cycles in order to initialize the analog circuitry,
as shown in
Figure 15-4. ADC Timing Diagram, First Conversion (Single Conversion Mode)
The actual sample-and-hold takes place 1.5 ADC clock cycles after the start of a normal conver-
sion and 13.5 ADC clock cycles after the start of an first conversion. See
conversion is complete, the result is written to the ADC Data Registers, and ADIF is set. In Sin-
gle Conversion mode, ADSC is cleared simultaneously. The software may then set ADSC again,
and a new conversion will be initiated on the first rising ADC clock edge.
Cycle Number
ADC Clock
ADEN
ADSC
ADIF
ADCH
ADCL
Figure 15-4
1
2
MUX and REFS
Update
ADEN
START
below.
12
ADPS0
ADPS1
ADPS2
13
CK
14
15
Sample & Hold
16
Reset
First Conversion
17
7-BIT ADC PRESCALER
18
ADC CLOCK SOURCE
19
20
21
22
Conversion
Complete
23
24
25
Figure
Sign and MSB of Result
Next
Conversion
1
LSB of Result
15-5. When a
2588E–AVR–08/10
2
MUX and REFS
Update
3