NEC NEC PD78081(A), User Manual

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CHAPTER 10 A/D CONVERTER
CHAPTER 10 A/D CONVERTER
10.1 A/D Converter Functions
The A/D converter converts an analog input into a digital value. It consists of 8 channels (ANI0 to ANI7) with an
8-bit resolution.
The conversion method is based on successive approximation and the conversion result is held in the 8-bit A/D
conversion result register (ADCR).
The following two ways are available to start A/D conversion.
(1) Hardware start
Conversion is started by trigger input (INTP3).
(2) Software start
Conversion is started by setting the A/D converter mode register.
Select 1 channel of analog input from ANI0 to ANI7 and perform A/D conversion. As for A/D conversion operations,
when the hardware is started up, the A/D conversion operation stops when A/D conversion is completed, and an
interrupt request (INTAD) is generated. In the case of software start, the A/D conversion operation is repeated. Each
time an A/D conversion operation ends, an interrupt request (INTAD) is generated.
10.2 A/D Converter Configuration
The A/D converter consists of the following hardware.
Table 10-1. A/D Converter Configuration
Item Configuration
Analog input 8 Channels (ANI0 to ANI7)
Control register A/D converter mode register (ADM)
A/D converter input select register (ADIS)
External interrupt mode register 1 (INTM1)
Register Successive approximation register (SAR)
A/D conversion result register (ADCR)