UPD75518 NEC, UPD75518 Datasheet - Page 118

• Manufacturer Part Number: UPD75518
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

118
(2) Pins of the A/D converter
(3) A/D conversion mode register
Note If the reference voltage (AV
(a) AN0 to AN7
(b) AV
The A/D conversion mode register (ADM) is an 8-bit register which operates as follows:
• Selects analog input channels.
• Selects comparator bias voltage.
• Directs the start of conversion and detects the completion of conversion.
ADM is set with an 8-bit manipulation instruction.
Bit 2 (EOC) and bit 3 (SOC) can be manipulated on a bit-by-bit basis.
The generation of a RESET signal initializes ADM to 04H. That is, only EOC is set to 1, with all bits cleared
to 0.
AN0 to AN7 are the input pins for eight analog signal channels. Analog signals subject to A/D
conversion are applied to these pins.
The A/D converter contains a sample-and-hold circuit, and analog input voltages are internally
maintained during A/D conversion.
A reference voltage for the A/D converter is applied to these pins.
By using an applied voltage across AV
digital signals.
AV
conversion may be lowered. To correct such lowered accuracy, selecting comparator bias
voltage is provided.
REF
SS
, AV
must be always V
SS
SS
.
REF
Note
) of the A/D converter does not exceed 0.65V
REF
and AV
SS
, signals applied to AN0 to AN7 are converted to
DD
, the accuracy of
PD75518(A)