ST7263 STMICROELECTRONICS [STMicroelectronics], ST7263 Datasheet - Page 26

• Manufacturer Part Number: ST7263
• Description: LOW SPEED USB 8-BIT MCU FAMILY with up to 16K MEMORY, up to 512 BYTES RAM, 8-BIT ADC, WDG, TIMER, SCI & I2C
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST7263
I/O PORTS (Cont’d)
Analog Alternate Function
When the pin is used as an ADC input the I/O must
be configured as input, floating. The analog multi-
plexer (controlled by the ADC registers) switches
the analog voltage present on the selected pin to
the common analog rail which is connected to the
ADC input.
It is recommended not to change the voltage level
or loading on any port pin while conversion is in
progress. Furthermore it is recommended not to
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have clocking pins located close to a selected an-
alog pin.
Warning : The analog input voltage level must be
within the limits stated in the Absolute Maximum
Ratings.
5.1.3 I/O Port Implementation
The hardware implementation on each I/O port de-
pends on the settings in the DDR register and spe-
cific feature of the I/O port such as ADC Input or
true open drain.