upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 191

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

10.4.3 A/D converter operation mode
ANI3 by the analog input channel specification register (ADS) and A/D conversion is executed.
register (PFM).
(1) A/D conversion operation (when PFEN = 0)
The operation mode of the A/D converter is the select mode. One analog input channel is selected from ANI0 to
In addition, the following two functions can be selected by setting bit 7 (PFEN) of the power-fail comparison mode
• Normal 10-bit A/D converter (PFEN = 0)
• Power-fail detection function (PFEN = 1)
A/D conversion
By setting bit 7 (ADCS) of the A/D converter mode register (ADM) to 1 and bit 7 (PFEN) of the power-fail
comparison mode register (PFM) to 0, A/D conversion of the voltage applied to the analog input pin specified by
the analog input channel specification register (ADS) is started.
When A/D conversion has been completed, the result of the A/D conversion is stored in the A/D conversion result
register (ADCR), and an interrupt request signal (INTAD) is generated. Once the next A/D conversion has started
and when one A/D conversion has been completed, the A/D conversion operation after that is immediately started.
The A/D conversion operations are repeated until new data is written to ADS.
If ADM, ADS, the power-fail comparison mode register (PFM), and the power-fail comparison threshold register
(PFT) are rewritten during A/D conversion, the A/D conversion operation under execution is stopped and
restarted from the beginning.
If 0 is written to ADCS during A/D conversion, A/D conversion is immediately stopped.
conversion result is undefined.
Remarks 1. n = 0 to 3
(PFEN = 0)
INTAD
ADCR
2. m = 0 to 3
Rewriting ADM
ADCS = 1
ANIn
Figure 10-11. A/D Conversion Operation
CHAPTER 10 A/D CONVERTER
User’s Manual U16846EJ3V0UD
ANIn
ANIn
Conversion is stopped
Conversion result is not retained
Rewriting ADS
ANIn
ANIn
ANIm
ANIm
ADCS = 0
ANIm
At this time, the
Stopped
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