Motorola MC68HC908AB32 User Manual

General Description
Technical Data MC68HC908AB32 — Rev. 1.0
34 General Description MOTOROLA
1.6 Pin Functions
Description of pin functions are provided here.
1.6.1 Power Supply Pins (V
DD
and V
SS
)
V
DD
and V
SS
are the power supply and ground pins. The MCU operates
from a single power supply.
Fast signal transitions on MCU pins place high, short-duration current
demands on the power supply. To prevent noise problems, take special
care to provide power supply bypassing at the MCU as Figure 1-3
shows. Place the C1 bypass capacitor as close to the MCU as possible.
Use a high-frequency-response ceramic capacitor for C1. C2 is an
optional bulk current bypass capacitor for use in applications that require
the port pins to source high current levels.
Figure 1-3. Power Supply Bypassing
V
SS
is also the ground for the port output buffers and the ground return
for the serial clock in the serial peripheral interface module (SPI). See
Section 16. Serial Peripheral Interface Module (SPI).
V
SS
must be grounded for proper MCU operation.
MCU
V
DD
C2
C1
0.1 µF
V
SS
V
DD
+
NOTE: Component values shown
represent typical applications.

Motorola MC68HC908AB32 Specifications

General

Brand	Motorola
Model	MC68HC908AB32
Category	Controller
Language	English