ATmega168 Automotive Atmel Corporation, ATmega168 Automotive Datasheet - Page 249

• Manufacturer Part Number: ATmega168 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega168 Automotive

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 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: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

21.6
21.6.1
7530I–AVR–02/10
ADC Conversion Result
ADC Multiplexer Selection Register – ADMUX
After the conversion is complete (ADIF is high), the conversion result can be found in the ADC
Result Registers (ADCL, ADCH).
For single ended conversion, the result is
where V
Table 21-2 on page 249
0x3FF represents the selected reference voltage minus one LSB.
• 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 21-2.
• 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
• Bit 4 – Res: Reserved Bit
This bit is an unused bit in the ATmega48/88/168, and will always read as zero.
• Bits 3:0 – MUX3:0: Analog Channel Selection Bits
Bit
Read/Write
Initial Value
REFS1
0
0
1
1
251.
IN
is the voltage on the selected input pin and V
REFS0
Voltage Reference Selections for ADC
0
1
0
1
REFS1
R/W
7
0
Voltage Reference Selection
AREF, Internal V
AV
Reserved
Internal 1.1V Voltage Reference with external capacitor at AREF pin
REFS0
R/W
and
CC
6
0
with external capacitor at AREF pin
Table 21-3 on page
ADLAR
R/W
5
0
ADC
ref
ATmega48/88/168 Automotive
turned off
=
R
4
–
0
V
---------------------------- -
IN
“The ADC Data Register – ADCL and ADCH” on
V
REF
250). 0x000 represents analog ground, and
1024
MUX3
R/W
3
0
REF
the selected voltage reference (see
MUX2
R/W
2
0
Table
MUX1
R/W
1
0
21-2. If these bits are
MUX0
R/W
0
0
ADMUX
249