s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 101

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

The oscillator configuration uses five components:
10.3.5 RC Oscillator
The RC oscillator circuit is designed for use with an external resistor (R
a tolerance within 25% of the expected frequency. See
The capacitor (C) for the RC oscillator is internal to the MCU. The R
or less to minimize its effect on the frequency.
In this configuration, the OSC2 pin can be used as general-purpose input/output (I/O) port pins or other
alternative pin function. The OSC2EN bit can be set to enable the OSC2 output function on the pin.
Enabling the OSC2 output can affect the external RC oscillator frequency, f
Freescale Semiconductor
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Crystal, X
Fixed capacitor, C
Tuning capacitor, C
Feedback resistor, R
Series resistor, R
The series resistor (R
oscillator guidelines and may not be required for all ranges of operation,
especially with high frequency crystals. Refer to the oscillator
characteristics table in the Electricals section for more information.
1
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
SIMOSCEN (internal signal) OR
OSCENINSTOP (bit located in
MCU
configuration register))
S
Figure 10-2. XTAL Oscillator External Connections
1
(optional)
2
OSC1
B
(can also be a fixed capacitor)
C
1
S
) is included in the diagram to follow strict Pierce
R
X
B
1
XTALCLK
NOTE
OSC2
R
C
S
2
BUSCLKX4
See the electrical section for details.
Figure
2
10-3.
BUSCLKX2
EXT
EXT
value must have a tolerance of 1%
) to provide a clock source with
RCCLK
.
Functional Description
101