Motorola MC68HC908AB32 User Manual

Analog-to-Digital Converter (ADC)
Technical Data MC68HC908AB32 — Rev. 1.0
236 Analog-to-Digital Converter (ADC) MOTOROLA
ADCH[4:0] — ADC Channel Select Bits
ADCH[4:0] form a 5-bit field which is used to select one of the eight
ADC channels, ATD7–ATD0. The channels are detailed in
Table 14-1. Care should be taken when using a port pin as both an
analog and digital input simultaneously to prevent switching noise
from corrupting the analog signal.
The ADC subsystem is turned off when the channel select bits are all
set to 1. This feature allows for reduced power consumption for the
MCU when the ADC is not being used.
NOTE: Recovery from the disabled state requires one conversion cycle to
stabilize.
The voltage levels supplied from internal reference nodes, as specified
in Table 14-1, are used to verify the operation of the ADC converter both
in production test and for user applications.
Table 14-1. Mux Channel Select
ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 Input Select
00000 PTB0/ATD0
00001 PTB1/ATD1
00010 PTB2/ATD2
00011 PTB3/ATD3
00100 PTB4/ATD4
00101 PTB5/ATD5
00110 PTB6/ATD6
00111 PTB7/ATD7
01000
Reserved↓↓↓↓↓
11100
11101
V
REFH
11110
V
REFL
11111ADC power off
NOTE: If any unused channels are selected, the resulting ADC conversion will be unknown
or reserved.

Motorola MC68HC908AB32 Specifications

General

Brand	Motorola
Model	MC68HC908AB32
Category	Controller
Language	English