MC68HC08AZ0 Datasheet, PDF (16/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
General Description
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 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.
MCU
V_DD
V_SS
C1
0.1 µF
+
C2
V_DD
NOTE: Component values shown
represent typical applications.
Figure 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).
NOTE: V_SS must be grounded for proper MCU operation.
Oscillator pins
The OSC1 and OSC2 pins are the connections for the on-chip oscillator
(OSC1 and OSC2) circuit. See Clock Generator Module (CGM) on page 107.
External reset pin
(RST)
A ‘0’ on the RST pin forces the MCU to a known start-up state. RST is
bidirectional, allowing a reset of the entire system. It is driven low when
MC68HC08AZ0
14
General Description
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6-gen
MOTOROLA