NEC UPD789426 Series User Manual page 211

CHAPTER 11 10-BIT A/D CONVERTER (
(5) Timing of undefined A/D conversion result
The A/D conversion value may become undefined if the timing of the completion of A/D conversion and that
to stop the A/D conversion operation conflict. Therefore, read the A/D conversion result while the A/D
conversion operation is in progress. To read the A/D conversion result after the A/D conversion operation
has been stopped, stop the A/D conversion operation before the next conversion operation is completed.
Figures 11-8 and 11-9 show the timing at which the conversion result is read.
Figure 11-8. Conversion Result Read Timing (If Conversion Result Is Undefined)
End of A/D conversion
ADCR0
INTAD0
ADCS0
Normal conversion result is read.
Figure 11-9. Conversion Result Read Timing (If Conversion Result Is Normal)
End of A/D conversion
ADCR0
INTAD0
ADCS0
µ
PD789436 AND 789456 SUBSERIES)
End of A/D conversion
Normal conversion result
Normal conversion result
A/D conversion stops.
User's Manual U15075EJ2V1UD
Undefined value
A/D conversion Undefined value
stops. is read.
Normal conversion
result is read.
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