CHAPTER 12 ANALOG-TO-DIGITAL (A/D) CONVERTER

The analog-to-digital (A/D) converter can convert an analog input voltage to a digital value and set the A/D interrupt pending bit when it stores the result. It can also monitor a pin and set the A/D interrupt pending bit when the input voltage crosses over or under a programmed threshold voltage. This chapter describes the A/D converter and explains how to program it.

12.1 A/D CONVERTER FUNCTIONAL OVERVIEW

The A/D converter (Figure 12-1) can convert an analog input voltage to an 8- or 10-bit digital result and set the A/D interrupt pending bit when it stores the result. It can also monitor an input and set the A/D interrupt pending bit when the input voltage crosses over or under the pro- grammed threshold voltage.

Analog Inputs

 

 

 

 

 

 

 

 

 

EPA or PTS

 

 

 

 

 

Command

 

 

VREF

ANGND

 

 

 

Analog Mux

 

 

 

 

 

 

 

 

 

Control

 

Sample

Successive

 

Logic

 

Approximation

 

 

 

and Hold

 

A/D

 

 

 

 

Converter

Status

 

 

 

 

 

 

 

 

AD_RESULT

AD_COMMAND

AD_TIME

AD_TEST

Multiplexed with port inputs

 

 

 

 

 

 

 

 

 

A2652-02

Figure 12-1. A/D Converter Block Diagram

12-1

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Intel 8XC196MC, 8XC196MD, 8XC196MH manual 12.1 A/D Converter Functional Overview, Angnd