A/D Conversion End Interrupt Request Generation Timing - NEC PD78052 User Manual

(6) Interrupt request flag (ADIF)
The interrupt request flag (ADIF) is not cleared even if the A/D converter mode register (ADM) is changed.
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 have been set immediately before the ADM rewrite. In this case, if ADIF is read immediately
after the ADM rewrite, ADIF may be set despite the fact that the A/D conversion for the post-change analog
input has not ended.
When the A/D conversion is stopped and then resumed, clear the ADIF before it is resumed.
Figure 14-12. A/D Conversion End Interrupt Request Generation Timing
ADM Rewrite
(Start of ANIn Conversion)
A /D Conversion
ADCR
INTAD
(7) AV pin
DD
The AV pin is the analog circuit power supply pin, and supplies power to the input circuits of ANI0/P10 to
DD
ANI7/P17.
Therefore, be sure to apply the same voltage as V
so as to switch to a backup battery as shown in Figure 14-13.
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CHAPTER 14 A/D CONVERTER
ADM Rewrite
(Start of ANIm Conversion)
ANIn ANIn
ANIn
Figure 14-13. Handling of AV
Main
Capacitor
power
supply for back-up
ADIF is set but ANIm
conversion has not ended
ANIm
ANIn ANIm
to this pin even when the application circuit is designed
DD
Pin
DD
AV
REF0
V
DD
AV
DD
AV
SS
V
SS
ANIm
ANIm