ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 242

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• 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: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

ADC Conversion
Result
2490Q–AVR–06/10
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 97 on page 243
sents the selected reference voltage minus one LSB.
If differential channels are used, the result is
where V
GAIN the selected gain factor, and V
in two’s complement form, from 0x200 (-512d) through 0x1FF (+511d). Note that if the user
wants to perform a quick polarity check of the results, it is sufficient to read the MSB of the result
(ADC9 in ADCH). If this bit is one, the result is negative, and if this bit is zero, the result is posi-
tive.
Table 96
selected with a gain of GAIN and a reference voltage of V
Figure 121. Differential Measurement Range
Figure 121
- V
IN
POS
shows the resulting output codes if the differential input channel pair (ADCn - ADCm) is
REF
is the voltage on the selected input pin and V
/GAIN
is the voltage on the positive input pin, V
shows the decoding of the differential input range.
and
ADC
Table 98 on page
=
(
----------------------------------------------------------------------- -
Output Code
V
0x3FF
REF
POS
0x1FF
0x000
ADC
the selected voltage reference. The result is presented
–
0
V
0x200
NEG
=
244). 0x000 represents ground, and 0x3FF repre-
V
V
--------------------------
REF
) GAIN 512
IN
V
⋅
⋅
REF
1024
NEG
REF
⋅
REF
the voltage on the negative input pin,
the selected voltage reference (see
.
V
ATmega64(L)
REF
/GAIN Differential Input
Voltage (Volts)
242