MC68HC908KX2 MOTOROLA [Motorola, Inc], MC68HC908KX2 Datasheet - Page 252

• Manufacturer Part Number: MC68HC908KX2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Analog-to-Digital Converter (ADC)
Technical Data
252
NOTE:
ADCO — ADC Continuous Conversion Bit
ADCH4–ADCH0 — ADC Channel Select Bits
Recovery from the disabled state requires one conversion cycle to
stabilize.
1. If any unused channels are selected, the resulting ADC conversion will be unknown.
2. The voltage levels supplied from internal reference nodes as specified in the table are used
ADCH4
When set, the ADC will convert samples continuously and update the
ADR register at the end of each conversion. Only one conversion is
allowed when this bit is cleared. Reset clears the ADCO bit.
ADCH4–ADCH0 form a 5-bit field which is used to select the input for
the A/D measurement. The choices are one of four ADC channels, as
well as V
should be taken when using a port pin as both an analog and a 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 used. Reset sets these bits.
to verify the operation of the ADC converter both in production test and for user applica-
tions.
~
0
0
0
0
0
1
1
1
1
1 = Continuous ADC conversion
0 = One ADC conversion
Analog-to-Digital Converter (ADC)
REFH
ADCH3
0
0
0
0
0
~
1
1
1
1
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
and V
Table 17-1. Mux Channel Select
SS
ADCH2
. Input selection is detailed in
0
0
0
0
1
~
1
1
1
1
ADCH1
~
0
0
1
1
0
0
0
1
1
ADCH0
~
0
1
0
1
0
0
1
0
1
Table
ADC power off
Input Select
Unused
Unused
V
V
SSAD
PTB0
PTB1
PTB2
PTB3
REFH
17-1. Care
MOTOROLA
~
(2)
(2)
(1)
(1)