GMS81C1102 / GMS81C1202
(3) Pins AN0/RB0 and AN1/RA1 to AN7/RA7
noise. Therefore, avoid applying pulses to pins adjacent to
the pin undergoing A/D conversion.
The analog input pins AN0 to AN7 also function as input/
output port (PORT RA and RB0) pins. When A/D conver-
sion is performed with any of pins AN0 to AN7 selected,
be sure not to execute a PORT input instruction while con-
version is in progress, as this may reduce the conversion
resolution.
(4) AVREF pin input impedance
A series resistor string of approximately 10KΩ is connected be-
tween the AVREFpin and the VSS pin.
Therefore, if the output impedance of the reference voltage
source is high, this will result in parallel connection to the
series resistor string between the AVREF pin and the VSS pin, and
there will be a large reference voltage error.
Also, if digital pulses are applied to a pin adjacent to the
pin in the process of A/D conversion, the expected A/D
conversion value may not be obtainable due to coupling
56
Jan. 2002 ver 2.0
HYNIX [ HYNIX SEMICONDUCTOR ]
