upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 244

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(8) Interrupt request flag (ADIF)
(9) Conversion results just after A/D conversion start
(10) A/D conversion result register (ADCR) read operation
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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.
Remarks 1. n = 0 to 7
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 14
0. Take measures such as polling the A/D conversion end interrupt request (INTAD) and removing the first
conversion result.
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 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.
A/D conversion
ADCR
ADIF
2. m = 0 to 7
ADS rewrite
(start of ANIn conversion)
Figure 12-20. Timing of A/D Conversion End Interrupt Request Generation
ANIn
µ
s after the ADCE bit was set to 1, or if the ADCS bit is set to 1 with the ADCE bit =
CHAPTER 12 A/D CONVERTER
ADS rewrite
(start of ANIm conversion)
User’s Manual U16962EJ3V0UD
ANIn
ANIn
ANIm
ANIn
ADIF is set but ANIm conversion
has not ended.
ANIm
ANIm
ANIm