Datasheet

© 2009 Microchip Technology Inc. DS41203E-page 65
PIC16F688
8.0 ANALOG-TO-DIGITAL
CONVERTER (ADC) MODULE
The Analog-to-Digital Converter (ADC) allows
conversion of an analog input signal to a 10-bit binary
representation of that signal. This device uses analog
inputs, which are multiplexed into a single sample and
hold circuit. The output of the sample and hold is
connected to the input of the converter. The converter
generates a 10-bit binary result via successive
approximation and stores the conversion result into the
ADC result registers (ADRESL and ADRESH).
The ADC voltage reference is software selectable to
either V
DD or a voltage applied to the external reference
pins.
The ADC can generate an interrupt upon completion of
a conversion. This interrupt can be used to wake-up the
device from Sleep.
Figure 8-1 shows the block diagram of the ADC.
FIGURE 8-1: ADC BLOCK DIAGRAM
RA0/AN0
A/D
RA1/AN1/VREF
RA2/AN2
RC0/AN4
VDD
VREF
ADON
GO/DONE
VCFG = 1
VCFG = 0
CHS
VSS
RC1/AN5
RC2/AN6
RC3/AN7
RA4/AN3
ADRESH
ADRESL
10
10
ADFM
0 = Left Justify
1 = Right Justify
000
001
010
011
100
101
110
111