Cautions For A/D Converter - NEC 78K0S/KA1+ User Manual

10.6 Cautions for A/D Converter

(1) Operating current in STOP mode
The A/D converter stops operating in the STOP mode. At this time, the operating current can be reduced by
clearing bit 7 (ADCS) and bit 0 (ADCE) of the A/D converter mode register (ADM) to 0.
(2) Input range of ANI0 to ANI3
Observe the rated range of the ANI0 to ANI3 input voltage. If a voltage of AV
in the range of absolute maximum ratings) is input to an analog input channel, the converted value of that channel
becomes undefined. In addition, the converted values of the other channels may also be affected.
(3) Conflicting operations
<1> Conflict between A/D conversion result register (ADCR, ADCRH) write and ADCR, ADCRH read by
instruction upon the end of conversion
ADCR, ADCRH read has priority. After the read operation, the new conversion result is written to ADCR,
ADCRH.
<2> Conflict between ADCR, ADCRH write and A/D converter mode register (ADM) write or analog input
channel specification register (ADS) write upon the end of conversion
ADM or ADS write has priority. ADCR, ADCRH write is not performed, nor is the conversion end interrupt
signal (INTAD) generated.
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or higher and V or lower (even
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