NEC 78K0S/KA1+ Preliminary User's Manual page 171

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(8) Interrupt request flag (ADIF)
The interrupt request flag (ADIF) is not cleared even if the analog input channel specification register (ADS) is
changed.
Therefore, if an analog input pin is changed during A/D conversion, the A/D conversion result and ADIF for the
pre-change analog input may be set just before the ADS rewrite. Caution is therefore required since, at this time,
when ADIF is read immediately after the ADS rewrite, ADIF is set despite the fact A/D conversion for the post-
change analog input has not ended.
When A/D conversion is stopped and then resumed, clear ADIF before the A/D conversion operation is resumed.
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A/D conversion
Remarks 1. n = 0 to 3
(9) Conversion results just after A/D conversion start
The first A/D conversion value immediately after A/D conversion starts may not fall within the rating range if the
ADCS bit is set to 1 within 1
0. Take measures such as polling the A/D conversion end interrupt request (INTAD) and removing the first
conversion result.
(10) A/D conversion result register (ADCR, ADCRH) read operation
When a write operation is performed to the A/D converter mode register (ADM) and analog input channel
specification register (ADS), the contents of ADCR and ADCRH may become undefined. Read the conversion
result following conversion completion before writing to ADM and ADS. Using a timing other than the above may
cause an incorrect conversion result to be read.
Figure 10-21. Timing of A/D Conversion End Interrupt Request Generation
ADS rewrite
(start of ANIn conversion)
ANIn
ADCR,
ADCRH
ADIF
2. m = 0 to 3
µ
s after the ADCE bit was set to 1, or if the ADCS bit is set to 1 with the ADCE bit =
CHAPTER 10 A/D CONVERTER
ADS rewrite
(start of ANIm conversion)
ANIn ANIm
ANIn ANIn
Preliminary User's Manual U16898EJ1V0UD
ADIF is set but ANIm conversion
has not ended.
ANIm
ANIm ANIm
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