MC68HC908GT16 Datasheet, PDF (91/412 Pages) Motorola, Inc – Microcontrollers

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
CONVERSION
INTERRUPT ^COMPLETE
ADC
LOGIC
DISABLE
ADC
VOLTAGE IN
(V_ADIN)
V_REFH
V_REFL
CHANNEL
SELECT
ADCH4–ADCH0
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
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 data direction
register (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.
MC68HC908GT16 • MC68HC908GT8 — Rev. 2
MOTOROLA
Analog-to-Digital Converter (ADC)
Technical Data
91