![background image](http://html.mh-extra.com/html/nec/mpd780973-series/mpd780973-series_preliminary-users-manual_249267160.webp)
160
CHAPTER 13 A/D CONVERTER
13.5 A/D Converter Cautions
(1) Current consumption in standby mode
A/D converter stops operating in the standby mode. At this time, current consumption can be reduced by setting
bit 7 (ADCS1) of the A/D converter mode register (ADM1) to 0 to stop conversion.
Figure 13-9 shows how to reduce the current consumption in the standby mode.
Figure 13-9. Example of Method of Reducing Current Consumption in Standby Mode
AV
REF
AV
SS
P-ch
Series resistor string
ADCS1
(2) Input range of ANI0 to ANI4
The input voltages of ANI0 to ANI4 should be within the specification range. In particular, if a voltage higher
than AV
REF
or lower than AV
SS
is input (even if within the absolute maximum rating range), the conversion value
of that channel will be undefined and the conversion values of other channels may also be affected.
(3) Contending operations
<1>
Contention between A/D conversion result register (ADCR1) write and ADCR1 read by instruction
upon the end of conversion
ADCR1 read is given priority. After the read operation, the new conversion result is written to ADCR1.
<2>
Contention between ADCR1 write and A/D converter mode register (ADM1) write or analog input
channel specification register (ADS1) write upon the end of conversion
ADM1 or ADS1 write is given priority. ADCR1 write is not performed, nor is the conversion end interrupt
request signal (INTAD) generated.
Summary of Contents for mPD780973 Series
Page 2: ...2 MEMO ...
Page 66: ...66 MEMO ...
Page 98: ...98 MEMO ...
Page 138: ...138 MEMO ...
Page 164: ...164 MEMO ...
Page 182: ...182 MEMO ...
Page 204: ...204 MEMO ...
Page 244: ...244 MEMO ...
Page 262: ...262 MEMO ...
Page 278: ...278 MEMO ...
Page 290: ...290 MEMO ...