ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 201

• Manufacturer Part Number: ATmega8
• Manufacturer: Atmel Corporation

Specifications of ATmega8

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• 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 85
• 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: 3
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

The ADC Data
Register – ADCL and
ADCH
ADLAR = 0
ADLAR = 1
2486Z–AVR–02/11
• Bits 2:0 – ADPS2:0: ADC Prescaler Select Bits
These bits determine the division factor between the XTAL frequency and the input clock to the
ADC.
Table 76. ADC Prescaler Selections
When an ADC conversion is complete, the result is found in these two registers.
When ADCL is read, the ADC Data Register is not updated until ADCH is read. Consequently, if
the result is left adjusted and no more than 8-bit precision is required, it is sufficient to read
ADCH. Otherwise, ADCL must be read first, then ADCH.
The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the way the result is read from
the registers. If ADLAR is set, the result is left adjusted. If ADLAR is cleared (default), the result
is right adjusted.
• ADC9:0: ADC Conversion result
These bits represent the result from the conversion, as detailed in
page
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
ADPS2
199.
0
0
0
0
1
1
1
1
ADC7
ADC9
ADC1
15
15
R
R
R
R
–
7
0
0
7
0
0
ADC6
ADC8
ADC0
14
14
ADPS1
R
R
R
R
–
6
0
0
6
0
0
0
0
1
1
0
0
1
1
ADC5
ADC7
13
13
R
R
R
R
–
5
0
0
–
5
0
0
ADC4
ADC6
12
12
R
R
R
R
–
4
0
0
–
4
0
0
ADPS0
0
1
0
1
0
1
0
1
ADC3
ADC5
11
11
R
R
R
R
–
3
0
0
–
3
0
0
ADC2
ADC4
10
10
R
R
R
R
–
2
0
0
–
2
0
0
ADC9
ADC1
ADC3
Division Factor
R
R
R
R
9
1
0
0
9
–
1
0
0
“ADC Conversion Result” on
128
16
32
64
2
2
4
8
ADC8
ADC0
ADC2
ATmega8(L)
R
R
R
R
8
0
0
0
8
–
0
0
0
ADCH
ADCL
ADCH
ADCL
201