ST7FMC1K2B3 STMICROELECTRONICS [STMicroelectronics], ST7FMC1K2B3 Datasheet - Page 237

• Manufacturer Part Number: ST7FMC1K2B3
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

10-BIT A/D CONVERTER (ADC) (Cont’d)
10.8.3.3 Digital A/D Conversion Result
The conversion is monotonic, meaning that the re-
sult never decreases if the analog input does not
and never increases if the analog input does not.
If the input voltage (V
(high-level voltage reference) then the conversion
result is FFh in the ADCDRMSB register and 03h
in the ADCDRLSB register (without overflow indi-
cation).
If the input voltage (V
level voltage reference) then the conversion result
in the ADCDRMSB and ADCDRLSB registers is
00 00h.
The A/D converter is linear and the digital result of
the conversion is stored in the ADCDRMSB and
ADCDRLSB registers. The accuracy of the con-
version is described in the Electrical Characteris-
tics Section.
R
for an analog input signal. If the impedance is too
high, this will result in a loss of accuracy due to
leakage and sampling not being completed in the
alloted time.
R
mented in the device between V
AIN
REF
is the maximum recommended impedance
is the value of the resistive bridge imple-
AIN
AIN
) is lower than V
) is greater than V
REF+
and V
REF-
REF-.
(low-
REF+
10.8.3.4 A/D Conversion
The analog input ports must be configured as in-
put, no pull-up, no interrupt. Refer to the «I/O
ports» chapter. Using these pins as analog inputs
does not affect the ability of the port to be read as
a logic input. If the application used the high-im-
pedance analog inputs, then the sample time
should be stretched by setting the ADSTS bit in
the MCCBCR register.
In the ADCCSR register:
ADC Conversion mode
In the ADCCSR register:
– Set the ADON bit to enable the A/D converter
– The EOC bit is kept low by hardware during the
Note: Changing the A/D channel during conver-
sion will stop the current conversion and start con-
version of the newly selected channel.
and to start the conversion. From this time on,
the ADC performs a continuous conversion of
the selected channel.
conversion.
– Select the CS[3:0] bits to assign the analog
channel to convert.
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