ATmega64M1 Atmel Corporation, ATmega64M1 Datasheet - Page 234

• Manufacturer Part Number: ATmega64M1
• Manufacturer: Atmel Corporation

Specifications of ATmega64M1

• Flash (kbytes): 64 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: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• 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: 2
• Output Compare Channels: 14
• Input Capture Channels: 1
• Pwm Channels: 10
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

21.7
234
ADC Conversion Result
ATmega16M1/32M1/64M1
Figure 21-13. Differential Non-linearity (DNL)
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 21-4 on page 242
0x3FF represents the selected reference voltage.
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 result, it is sufficient to read the MSB of the result
(ADC9 in ADCH). If the bit is one, the result is negative, and if this bit is zero, the result is posi-
tive.
Table 21-2 on page 235
(ADCn - ADCm) is selected with a reference voltage of V
• Quantization Error: Due to the quantization of the input voltage into a finite number of codes,
• Absolute Accuracy: The maximum deviation of an actual (unadjusted) transition compared to
a range of input voltages (1 LSB wide) will code to the same value. Always ±0.5 LSB
an ideal transition for any code. This is the compound effect of offset, gain error, differential
error, non-linearity, and quantization error. Ideal value: ±0.5 LSB
Figure 21-14 on page 235
IN
POS
is the voltage on the selected input pin and V
is the voltage on the positive input pin, V
Output Code
0x000
0x3FF
and
shows the resulting output codes if the differential input channel pair
0
Table 21-5 on page
shows the decoding of the differential input range.
1 LSB
ADC
REF
ADC
=
the selected voltage reference. The result is presented
(
----------------------------------------------------------------------- -
V
POS
=
V
--------------------------
–
IN
V
243). 0x000 represents analog ground, and
V
⋅
REF
NEG
1023
NEG
V
REF
REF
) GAIN 512
REF
⋅
the voltage on the negative input pin,
.
the selected voltage reference (see
V
⋅
REF
Input Voltage
8209D–AVR–11/10