NEC PD78058F(A) Manuale Utente
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CHAPTER 14 A/D CONVERTER
14.1 A/D Converter Functions
The A/D converter converts an analog input into a digital value. It consists of 8 channels (ANI0 to ANI7) with an
8-bit resolution.
The conversion method is based on successive approximation and the conversion result is held in the 8-bit A/D
conversion result register (ADCR).
The following two methods are used for starting an A/D conversion operation.
(1) Hardware start
Conversion is started by trigger input (INTP3).
(2) Software start
Conversion is started by setting the A/D converter mode register (ADM).
Select 1 channel from the analog inputs ANI0 to ANI7 and execute A/D conversion. An A/D conversion operation
ends after the A/D conversion operation at hardware start is completed and an interrupt request (INTAD) is generated.
In the case of software start, the A/D conversion operation is repeated. Each time an A/D conversion ends, an interrupt
request (INTAD) is generated.
Cautions
For pins which have common functions with a port (See 3.1.1 or 4.1.1 Normal operating mode
pins, (1) Port pins), do not execute the following operations during A/D conversion. If
performed, then the general error standards cannot be maintained during A/D conversion.
<1> If it is used as a port, rewriting the output latch of its output.
<2> Even if it is not used as a port, changing the output level of pins used as outputs.