mc68hc705k1 Freescale Semiconductor, Inc, mc68hc705k1 Datasheet - Page 21

• Manufacturer Part Number: mc68hc705k1
• Description: Hcmos Microcontroller Unit
• Manufacturer: Freescale Semiconductor, Inc

1.6.2.2 Ceramic Resonator
MC68HC705K1 — Rev. 2.0
NOTE:
Use an AT-cut crystal and not a strip or tuning fork crystal. The MCU may
overdrive or have the wrong characteristic impedance for a strip or
tuning fork crystal.
To use the crystal-driven oscillator, the RC and PIN3 bits in the mask
option register must be clear. See
the RC bit connects an internal 2-M startup resistor between OSC1
and OSC2.
To reduce cost, use a ceramic resonator in place of the crystal. Use the
circuit in
3-pin ceramic resonator, and follow the resonator manufacturer’s
recommendations. The resonator parameters determine the external
component values required for maximum stability and reliable starting.
The load capacitance values used in the oscillator circuit design should
include all stray layout capacitances. To minimize output distortion,
mount the resonator and capacitors as close as possible to the pins.
Freescale Semiconductor, Inc.
27 pF
For More Information On This Product,
C3
Figure 1-5
Figure 1-5. 2-Pin Ceramic Resonator Connections
Go to: www.freescale.com
RESONATOR
CERAMIC
2 M
MCU
General Description
for a 2-pin ceramic resonator or
27 pF
C4
9.6 Mask Option
OSC1
OSC2
V
V
Register. Clearing
DD
SS
Figure 1-6
General Description
Pin Assignments
C1 C2
Technical Data
CER.
RES.
for a
V
SS