MC908GR8CDWE Datasheet, PDF (81/408 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Freescale Semiconductor, Inc.
Analog-to-Digital Converter (ADC)
Functional Description
INTERNAL
DATA BUS
READ DDRBx
WRITE DDRBx
RESET
WRITE PTBx
READ PTBx
DDRBx
PTBx
DISABLE
PTBx
ADC CHANNEL x
ADC DATA REGISTER
DISABLE
ADC
CONVERSION
VOLTAGE IN
INTERRUPT ^COMPLETE
ADC
LOGIC
(V_ADIN)
CHANNEL ^{ADCH4–ADCH0}
SELECT
AIEN
COCO
CGMXCLK
BUS CLOCK
ADC CLOCK
CLOCK
GENERATOR
ADIV2–ADIV0 ADICLK
Figure 5-1. ADC Block Diagram
5.4.1 ADC Port I/O Pins
PTB5/ATD5–PTB0/ATD0 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.
MC68HC908GR8 — Rev 4.0
MOTOROLA
Analog-to-Digital Converter (ADC)
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Technical Data
81