NEC 78K0/KD1 Series User Manual page 237

The setting methods are described below.
• When used as A/D conversion operation
<1> Set bit 0 (ADCE) of the A/D converter mode register (ADM) to 1.
<2> Select the channel and conversion time using bits 2 to 0 (ADS2 to ADS0) of the analog input channel
specification register (ADS) and bits 5 to 3 (FR2 to FR0) of ADM.
<3> Set bit 7 (ADCS) of ADM to 1.
<4> An interrupt request signal (INTAD) is generated.
<5> Transfer the A/D conversion data to the A/D conversion result register (ADCR).
<Change the channel>
<6> Change the channel using bits 2 to 0 (ADS2 to ADS0) of ADS.
<7> An interrupt request signal (INTAD) is generated.
<8> Transfer the A/D conversion data to the A/D conversion result register (ADCR).
<Complete A/D conversion>
<9> Clear ADCS to 0.
<10> Clear ADCE to 0.
Cautions 1. Make sure the period of <1> to <3> is 14 µ µ µ µ s or more.
2. It is no problem if the order of <1> and <2> is reversed.
3. <1> can be omitted. However, do not use the first conversion result after <3> in this
case.
4. The period from <4> to <7> differs from the conversion time set using bits 5 to 3 (FR2 to
FR0) of ADM. The period from <6> to <7> is the conversion time set using FR2 to FR0.
• When used as power-fail function
<1> Set bit 7 (PFEN) of the power-fail comparison mode register (PFM) to 1.
<2> Set power-fail comparison condition using bit 6 (PFCM) of PFM.
<3> Set bit 0 (ADCE) of the A/D converter mode register (ADM) to 1.
<4> Select the channel and conversion time using bits 2 to 0 (ADS2 to ADS0) of the analog input channel
specification register (ADS) and bits 5 to 3 (FR2 to FR0) of ADM.
<5> Set a threshold value to the power-fail comparison threshold register (PFT).
<6> Set bit 7 (ADCS) of ADM to 1.
<7> Transfer the A/D conversion data to the A/D conversion result register (ADCR).
<8> ADCR and PFT are compared and an interrupt request signal (INTAD) is generated if the conditions
match.
<Change the channel>
<9> Change the channel using bits 2 to 0 (ADS2 to ADS0) of ADS.
<10> Transfer the A/D conversion data to the A/D conversion result register (ADCR).
<11> ADCR and the power-fail comparison threshold register (PFT) are compared and an interrupt request
signal (INTAD) is generated if the conditions match.
<Complete A/D conversion>
<12> Clear ADCS to 0.
<13> Clear ADCE to 0.
Cautions 1. Make sure the period of <3> to <6> is 14 µ µ µ µ s or more.
2. It is no problem if order of <3>, <4>, and <5> is changed.
3. <3> can be omitted. However, do not use the first conversion result after <6> in this
case.
4. The period from <7> to <11> differs from the conversion time set using bits 5 to 3 (FR2 to
FR0) of ADM. The period from <9> to <11> is the conversion time set using FR2 to FR0.
CHAPTER 12 A/D CONVERTER
Preliminary User's Manual U16315EJ1V0UD
237