MC68HC05JJ6 Datasheet, PDF (26/216 Pages) Freescale Semiconductor, Inc – General Release Specification Microcontrollers

General Description
MCU
2 MΩ
OSC1
OSC2
MCU
OSC1
R
OSC2
MCU
OSC1
OSC2
UNCONNECTED
(a) Crystal or
Ceramic Resonator
Connections
(b) RC Oscillator
Connections
EXTERNAL CLOCK
(c) External
Clock Source
Connection
Figure 1-3. EPO Oscillator Connections
1.7.1 Crystal Oscillator
The circuit in Figure 1-3 (a) shows a typical oscillator circuit for an AT-
cut, parallel resonant crystal. The crystal manufacturer’s
recommendations should be followed, as the crystal parameters
determine the external component values required to provide maximum
stability and reliable startup. The load capacitance values used in the
oscillator circuit design should include all stray capacitances. The crystal
and components should be mounted as close as possible to the pins for
startup stabilization and to minimize output distortion. An internal startup
resistor of approximately 2 MΩ can be provided by the shunt resistor
mask option between OSC1 and OSC2 for the crystal type oscillator.
The crystal configuration is enabled by choosing the crystal selection in
the oscillator connections mask option.
NOTE:
In general, a 32-kHz crystal is not recommended for use with the EPO
on the MC68HC05JJ6/MC68HC05JP6 unless specifically indicated by
the crystal manufacturer.
General Release Specification
26
MC68HC05JJ6/MC68HC05JP6 — Rev. 3.2
General Description
Freescale Semiconductor