Operation In Scan Mode - NEC UPD703116 User Manual

13.7.2 Operation in scan mode

Pins from the conversion start analog input pin through the conversion termination analog input pin specified in the
ADSCM00 or ADSCM10 register are sequentially selected and A/D converted. An A/D conversion result is stored in
the ADCR0n or ADCR1n register corresponding to the analog input (n = 0 to 7). When conversion terminates for all
analog inputs through the conversion termination analog input pin, an A/D conversion termination interrupt (INTAD0,
INTAD1) is generated. A/D conversion operation repeats until the ADCE0 or ADCE1 bit = 0 (ADCS0 or ADCS1 bit =
1).
Analog Input A/D Conversion Result Register
Note 1
ANIx ADCRx
| |
Note 2
ANIx ADCRx
Notes 1. Set using SANI3 to SANI0 bits of ADSCM00 or ADSCM10 register.
Be sure to set a pin number that is smaller than the conversion termination analog input pin number
set according to Note 2.
2. Set using ANIS3 to ANIS0 bits of ADSCM00 or ADSCM10 register.
Remark x = 00 to 07, 10 to 17
It is not necessary to write 1 in the ADCE0 or ADCE1 bit of the ADSCM00 or ADSCM10 register as an A/D
conversion restart operation in A/D trigger polling mode
This is optimal for applications that regularly read A/D conversion values.
Note In A/D trigger polling mode, the fact that the ADCE0 or ADCE1 bit of the ADSCM00 or ADSCM10 register
is 0 means that A/D conversion operation does not stop as long as the ADCS0 or ADCS1 bit is not 0.
Therefore, if the ADCR0n or ADCR1n register is not read before the next A/D conversion, it is overwritten.
Figure 13-9. Example of Scan Mode (A/D Trigger Polling Scan) Operation (ANI02 to ANI05)
: For A/D Converter 0
ADSCM00
(1) ADCE0 bit of ADSCM00 = 1 (Enabled)
(2) A/D conversion of ANI02
(3) Store conversion result in ADCR02
(4) A/D conversion of ANI03
(5) Store conversion result in ADCR03
(6) A/D conversion of ANI04
CHAPTER 13 A/D CONVERTER
Note
.
ANI00
ANI01
ANI02
ANI03 A/D converter 0
ANI04
ANI05
ANI06
ANI07
(7) Store conversion result in ADCR04
(8) A/D conversion of ANI05
(9) Store conversion result in ADCR05
(10) Generate INTAD0 interrupt
(11) Return to (2)
User's Manual U14492EJ5V0UD
ADCR00
ADCR01
ADCR02
ADCR03
ADCR04
ADCR05
ADCR06
ADCR07
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