NEC V850ES/KE1+ User Manual page 387

(7) Interrupt request flag (ADIC.ADIF bit)
Even when the ADS register is changed, the ADIF bit is not cleared (0).
Therefore, if the analog input pin is changed during A/D conversion, the ADIF bit may be set (1) because A/D
conversion of the previous analog input pin ends immediately before the ADS register is rewritten. In a such
case, note that if the ADIF bit is read immediately after the ADS register has been rewritten, the ADIF bit is set
(1) even though A/D conversion of the analog input pin after the change has not been completed.
When stopping A/D conversion once and resuming it, clear the ADIF bit (0) before resuming A/D conversion.
A/D conversion
ADCR
INTAD
Remark n = 0 to 7
m = 0 to 7
(8) Conversion results immediately after A/D conversion start
If the ADM.ADCS bit is set to 1 within 1
bit has been set to 1, or if the ADCS bit is set to 1 with the ADCS2 bit cleared to 0, the converted value
immediately after the A/D conversion operation has started may not satisfy the rating. Take appropriate
measures such as polling the A/D conversion end interrupt request signal (INTAD) and discarding the first
conversion result.
(9) Reading A/D conversion result register (ADCR)
When the ADM or ADS register has been written, the contents of the ADCR register may become undefined.
When the conversion operation is complete, read the conversion results before writing to the ADM or ADS
register. A correct conversion result may not be able to be read at a timing other than the above.
Accessing the ADCR and ADCRH registers is prohibited in the following statuses. For details, refer to 3.4.8
<R>
(1) (b) Access to special on-chip peripheral I/O register.
• When the CPU operates on the subclock and the main clock oscillation is stopped
• When the CPU operates on the internal oscillation clock
CHAPTER 13 A/D CONVERTER
Figure 13-9. A/D Conversion End Interrupt Request Occurrence Timing
ADS rewrite
(ANIn conversion start)
ANIn
ADS rewrite
(ANIm conversion start)
ANIn ANIm
ANIn ANIn
μ
s (high-speed mode) or 14
User's Manual U16896EJ2V0UD
ANIm conversion is not complete
even though ADIF is set.
ANIm
ANIm
μ
s (normal mode) after the ADM.ADCS2
ANIm
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