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10.8 10-BIT A/D CONVERTER (ADC)
10.8.1 Introduction
The on-chip Analog to Digital Converter (ADC) pe-
ripheral is a 10-bit, successive approximation con-
verter with internal sample and hold circuitry. This
peripheral has up to 16 multiplexed analog input
channels (refer to device pin out description) that
allow the peripheral to convert the analog voltage
levels from up to 16 different sources.
The result of the conversion is stored in a 10-bit
Data Register. The A/D converter is controlled
through a Control/Status Register.
10.8.2 Main Features
■ 10-bit conversion
■ Up to 16 channels with multiplexed input
■ Linear successive approximation
■ Data register (DR) which contains the results
■ Conversion complete status flag
■ On/off bit (to reduce consumption)
The block diagram is shown in Figure 68.
Figure 68. ADC Block Diagram
CH2 CH1EOC SPEED ADON 0 CH0
ADCCSR
AIN0
AIN1
ANALOG TO DIGITAL
CONVERTER
AINx
ANALOG
MUX
D4 D3D5D9 D8 D7 D6 D2
ADCDRH
4
DIV 4
f
ADC
f
CPU
D1 D0
ADCDRL
0
1
00 00 00
CH3
DIV 2