Analog-to-Digital Converter (ADC)
Functional Description
MC68HC908GP32
•
MC68HC08GP32
—
Rev. 6
Technical Data
MOTOROLA
Analog-to-Digital Converter (ADC)
89
Figure 5-1. ADC Block Diagram
5.4.1 ADC Port I/O Pins
PTB7/AD7–PTB0/AD0 are general-purpose I/O (input/output) pins that
share with the ADC channels. The channel select bits define which ADC
channel/port pin will be used as the input signal. The ADC overrides the
port I/O logic by forcing that pin as input to the ADC. The remaining ADC
channels/port pins are controlled by the port I/O logic and can be used
as general-purpose I/O. Writes to the port register or DDR will not have
any affect on the port pin that is selected by the ADC. Read of a port pin
in use by the ADC will return a logic 0.
INTERNAL
DATA BUS
READ DDRBx
WRITE DDRBx
RESET
WRITE PTBx
READ PTBx
PTBx
DDRBx
PTBx
INTERRUPT
LOGIC
CHANNEL
SELECT
ADC
CLOCK
GENERATOR
CONVERSION
COMPLETE
ADC
(V
ADIN
)
ADC CLOCK
CGMXCLK
BUS CLOCK
ADCH4–ADCH0
ADC DATA REGISTER
AIEN
COCO
DISABLE
DISABLE
ADC CHANNEL x
ADIV2–ADIV0
ADICLK
VOLTAGE IN
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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