ATmega329P Atmel Corporation, ATmega329P Datasheet - Page 225

• Manufacturer Part Number: ATmega329P
• Manufacturer: Atmel Corporation

Specifications of ATmega329P

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• 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: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• 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: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

22.9
22.9.1
8021G–AVR–03/11
Register Description
ADMUX – ADC Multiplexer Selection Register
• Bit 7:6 – REFS1:0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in
changed during a conversion, the change will not go in effect until this conversion is complete
(ADIF in ADCSRA is set). The internal voltage reference options may not be used if an external
reference voltage is being applied to the AREF pin.
Table 3. Voltage Reference Selections for ADC
• Bit 5 – 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 complete description of this bit, see
page
• Bits 4:0 – MUX4:0: Analog Channel Selection Bits
The value of these bits selects which combination of analog inputs are connected to the ADC.
See
in effect until this conversion is complete (ADIF in ADCSRA is set).
Bit
(0x7C)
Read/Write
Initial Value
REFS1
Table 22-3
0
0
1
1
228.
REFS0
0
1
0
1
REFS1
for details. If these bits are changed during a conversion, the change will not go
R/W
7
0
Voltage Reference Selection
AREF, Internal Voltage Reference turned off
AVCC with external capacitor at AREF pin
Reserved
Internal 1.1V Voltage Reference with external capacitor at AREF pin
REFS0
R/W
6
0
ADLAR
R/W
5
0
MUX4
R/W
4
0
”ADCL and ADCH – The ADC Data Register” on
MUX3
R/W
3
0
ATmega329P/3290P
MUX2
R/W
2
0
Table
MUX1
R/W
1
0
3. If these bits are
MUX0
R/W
0
0
ADMUX
225