s908gr16ag4cfj Freescale Semiconductor, Inc, s908gr16ag4cfj Datasheet - Page 50

• Manufacturer Part Number: s908gr16ag4cfj
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Analog-to-Digital Converter (ADC)
3.6.1 Wait Mode
The ADC continues normal operation during wait mode. Any enabled CPU interrupt request from the ADC
can bring the MCU out of wait mode. If the ADC is not required to bring the MCU out of wait mode, power
down the ADC by setting ADCH4–ADCH0 bits in the ADC status and control register before executing the
WAIT instruction.
3.6.2 Stop Mode
The ADC module is inactive after the execution of a STOP instruction. Any pending conversion is aborted.
ADC conversions resume when the MCU exits stop mode after an external interrupt. Allow one
conversion cycle to stabilize the analog circuitry.
3.7 I/O Signals
The ADC module has eight pins shared with port B, PTB7/AD7–PTB0/AD0.
3.7.1 ADC Analog Power Pin (V
The ADC analog portion uses V
potential as V
V
3.7.2 ADC Analog Ground Pin (V
The ADC analog portion uses V
potential as V
V
3.7.3 ADC Voltage Reference High Pin (V
The ADC analog portion uses V
pin to the same voltage potential as V
good results. Any noise present on this pin will be reflected and possibly magnified in A/D conversion
values.
V
50
DDAD
SSAD
DDAD
and V
and V
and V
REFL
REFH
REFH
DD
SS
For maximum noise immunity, route V
capacitors as close as possible to the package.
For maximum noise immunity, route V
capacitors as close as possible to the package. Routing V
parallel to V
.
. External filtering may be necessary to ensure clean V
are double-bonded on the MC68HC908GR16A.
are double-bonded on the MC68HC908GR16A.
are double-bonded on the MC68HC908GR16A.
REFL
Route V
DDAD
SSAD
REFH
may improve common mode noise rejection.
MC68HC908GR16A Data Sheet, Rev. 1.0
SSAD
DDAD
DD
as its ground pin. Connect the V
as its upper voltage reference pin. By default, connect the V
as its power pin. Connect the V
SSAD
. External filtering is often necessary to ensure a clean V
cleanly to avoid any offset errors.
)
)
REFH
NOTE
NOTE
NOTE
DDAD
REFH
)
carefully and place bypass
carefully and place bypass
DDAD
SSAD
DDAD
REFH
pin to the same voltage
pin to the same voltage
for good results.
close and
Freescale Semiconductor
REFH
REFH
for