mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 166

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Clock Generator Module (CGM)
10.4.4 CGM External Connections
Technical Data
In its typical configuration, the CGM requires seven external
components. Five of these are for the crystal oscillator and two are for
the PLL.
The crystal oscillator is normally connected in a Pierce oscillator
configuration, as shown in
logical representation of the internal components and may not represent
actual circuitry. The oscillator configuration uses five components:
The series resistor (R
especially with high-frequency crystals. Refer to the crystal
manufacturer’s data for more information.
Figure 10-3
Routing should be done with great care to minimize signal cross talk and
noise. See
information and more information on the filter capacitor’s value and its
effects on PLL performance.
1. Crystal, X
2. Fixed capacitor, C
3. Tuning capacitor, C
4. Feedback resistor, R
5. Series resistor, R
1. Bypass capacitor, C
2. Filter capacitor, C
Freescale Semiconductor, Inc.
For More Information On This Product,
Clock Generator Module (CGM)
10.10 Acquisition/Lock Time Specifications
Go to: www.freescale.com
also shows the external components for the PLL:
1
S
) may not be required for all ranges of operation,
S
F
1
(optional)
2
BYP
Figure
B
(can also be a fixed capacitor)
10-3.
Figure 10-3
MC68HC908AS60 — Rev. 1.0
shows only the
for routing