CHAPTER 10 8-BIT A/D CONVERTER (µPD789426 AND 789446 SUBSERIES)
(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 10-8 and 10-9 show the timing at which the conversion result is read.
Figure 10-8. Conversion Result Read Timing (If Conversion Result Is Undefined)
End of A/D conversion
End of A/D conversion
ADCR0
Normal conversion result
Undefined value
INTAD0
ADCS0
Normal conversion result is read.
A/D conversion
stops.
Undefined value
is read.
Figure 10-9. Conversion Result Read Timing (If Conversion Result Is Normal)
End of A/D conversion
ADCR0
Normal conversion result
INTAD0
ADCS0
A/D conversion stops.
Normal conversion
result is read.
User’s Manual U15075EJ1V0UM00
193
NEC [ NEC ]
