ATTINY44A-SSN Atmel, ATTINY44A-SSN Datasheet - Page 136

• Manufacturer Part Number: ATTINY44A-SSN
• Description: IC MCU AVR 4KB FLASH 20MHZ 14SOI
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY44A-SSN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 12
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Processor Series: ATTINY4x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

136
ATtiny24A/44A/84A
The ADC module contains a prescaler, as illustrated in
ates an acceptable ADC clock frequency from any CPU frequency above 100 kHz. The
prescaling is set by the ADPS bits in ADCSRA. The prescaler starts counting from the moment
the ADC is switched on by setting the ADEN bit in ADCSRA. The prescaler keeps running for as
long as the ADEN bit is set, and is continuously reset when ADEN is low.
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, as summarised in
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 16-4.
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 a 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.
Figure 16-5.
When Auto Triggering is used, the prescaler is reset when the trigger event occurs, as shown in
Figure 16-6
Cycle Number
ADC Clock
ADEN
ADSC
ADIF
ADCH
ADCL
Cycle Number
ADC Clock
ADSC
ADIF
ADCH
ADCL
below. This assures a fixed delay from the trigger event to the start of conversion. In
1
ADC Timing Diagram, First Conversion (Single Conversion Mode)
ADC Timing Diagram, Single Conversion
1
2
MUX and REFS
Update
2
MUX and REFS
Update
12
3
13
Sample & Hold
4
14
5
15
6
Sample & Hold
16
First Conversion
17
7
One Conversion
18
8
19
9
20
Figure 16-3 on page
10
Conversion
Complete
21
Figure 16-4
11
22
Conversion
Complete
23
12
Table 16-1 on page
24
13
below.
25
Figure
Sign and MSB of Result
Sign and MSB of Result
135, which gener-
LSB of Result
Next Conversion
1
Next
Conversion
1
LSB of Result
16-5. When a
8183C–AVR–03/11
2
MUX and REFS
Update
2
MUX and REFS
Update
138. The
3
3