Operation In Scan Mode - NEC UPD703116 User Manual

13.9.2 Operation in scan mode

Using an ADTRG0 or ADTRG1 signal as a trigger, pins from the conversion start analog input pin through the
conversion termination analog input pin specified by the ADSCM00 or ADSCM10 register are sequentially selected
and A/D converted. A/D conversion results are stored in the ADCR0n or ADCRN1n registers corresponding to the
analog inputs (n = 0 to 7). When conversion terminates for all of the specified analog inputs, an INTAD0 or INTAD1
interrupt is generated, which terminates A/D conversion (ADCS0 or ADCS1 = 0).
Trigger
ADTRGn signal
Remark n = 0, 1
After all specified A/D conversions terminate, A/D conversion is restarted when an external trigger signal occurs.
This is optimal for applications that regularly monitor multiple analog inputs in synchronization with an external
trigger.
Figure 13-13. Example of Scan Mode (External Trigger Scan) Operation: For A/D Converter 0
ADTRG0
(1) ADCE0 bit of ADSCM00 = 1 (Enabled)
(2) External trigger generation
(3) A/D conversion of ANI01
(4) Store conversion result in ADCR01
(5) A/D conversion of ANI02
(6) Store conversion result in ADCR02
CHAPTER 13 A/D CONVERTER
Analog Input
ANIn0
ANIn1
ANIn2
ANIn3
ANIn4
ANIn5
ANIn6
ANIn7
(a) When setting to scan ANI01 to ANI04
ANI00
ANI01
ANI02
ANI03
A/D converter 0
ANI04
ANI05
ANI06
ANI07
User's Manual U14492EJ5V0UD
A/D Conversion Result Register
ADCRn0
ADCRn1
ADCRn2
ADCRn3
ADCRn4
ADCRn5
ADCRn6
ADCRn7
(7) A/D conversion of ANI03
(8) Store conversion result in ADCR03
(9) A/D conversion of ANI04
(10) Store conversion result in ADCR04
(11) INTAD0 interrupt generation
ADCR00
ADCR01
ADCR02
ADCR03
ADCR04
ADCR05
ADCR06
ADCR07
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