MC-78F0712-KIT Renesas Electronics America, MC-78F0712-KIT Datasheet - Page 218

• Manufacturer Part Number: MC-78F0712-KIT
• Description: KIT REF SYSTEM 78K0 UPD78F0712
• Manufacturer: Renesas Electronics America

Specifications of MC-78F0712-KIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

13.5.4 Power-fail monitoring function
(PFM).
(1) Normal A/D conversion operation (when PFEN = 0)
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The following two functions can be selected by setting of bit 7 (PFEN) of the power-fail comparison mode register
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, the A/D conversion operation of the voltage, which is 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 A/D conversion has started and
when one A/D conversion has been completed, the next A/D conversion operation 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
Normal 10-bit A/D converter (PFEN = 0)
Power-fail detection function (PFEN = 1)
(PFEN = 0)
INTAD
ADCR
2. m = 0 to 3
Rewriting ADM
ADCS = 1
ANIn
Figure 13-13. A/D Conversion Operation
CHAPTER 13 A/D CONVERTER
User’s Manual U17890EJ2V0UD
ANIn
ANIn
Conversion is stopped
Conversion result is not retained
Rewriting ADS
ANIn
ANIn
ANIm
ANIm
ADCS = 0
ANIm
At this time, the
Stopped