21.7 ADC Conversion Result
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
V
⋅ 1024
IN
ADC = --------------------------
V
REF
where VIN is the voltage on the selected input pin and VREF the selected voltage reference (see
Table 21-3 on page 228 and Table 21-4 on page 229). 0x000 represents analog ground, and
0x3FF represents the selected reference voltage minus one LSB.
(V
– V
) ⋅ 512
NEG
POS
ADC = ----------------------------------------------------
V
REF
Figure 21-14. Differential Measurement Range
Output Code
0x1FF
0x000
0
Differential Input
Voltage (Volts)
- VREF
VREF
0x3FF
0x200
226
ATmega169P
8018A–AVR–03/06
ATMEL [ ATMEL ]
