mc68hc908mr32 Freescale Semiconductor, Inc, mc68hc908mr32 Datasheet - Page 64

• Manufacturer Part Number: mc68hc908mr32
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Clock Generator Module (CGM)
Figure 4-3
4.4 I/O Signals
This section describes the CGM input/output (I/O) signals.
4.4.1 Crystal Amplifier Input Pin (OSC1)
The OSC1 pin is an input to the crystal oscillator amplifier.
4.4.2 Crystal Amplifier Output Pin (OSC2)
The OSC2 pin is the output of the crystal oscillator inverting amplifier.
4.4.3 External Filter Capacitor Pin (CGMXFC)
The CGMXFC pin is required by the loop filter to filter out phase corrections. A small external capacitor is
connected to this pin.
4.4.4 PLL Analog Power Pin (V
V
potential as the V
4.4.5 Oscillator Enable Signal (SIMOSCEN)
The SIMOSCEN signal comes from the system integration module (SIM) and enables the oscillator and
PLL.
64
DDA
•
•
is a power pin used by the analog portions of the PLL. Connect the V
Bypass capacitor, C
Filter capacitor, C
also shows the external components for the PLL:
Routing should be done with great care to minimize signal cross talk and
noise. (See
and more information on the filter capacitor’s value and its effects on PLL
performance.)
To prevent noise problems, C
pin as possible, with minimum routing distances and no routing of other
signals across the C
Route V
capacitors as close as possible to the package.
DD
pin.
DDA
F
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
4.8 Acquisition/Lock Time Specifications
BYP
carefully for maximum noise immunity and place bypass
F
DDA
connection.
)
F
should be placed as close to the CGMXFC
NOTE
NOTE
NOTE
for routing information
DDA
pin to the same voltage
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