Freescale Semiconductor, Inc.
Clock Generator Module (CGM)
I/O Signals
SIMOSCEN
CGMXCLK
A
1
2
C
S
D
V
V
O
O
XM
V
G
DD
*
RS
CF
CBYP
RB
X
1
C1
C2
*R can be 0 (shorted) when used with higher-frequency crystals. Refer to manufacturer’s data.
S
Figure 10-3. CGM External Connections
10.5 I/O Signals
The following paragraphs describe the CGM input/output (I/O) signals.
10.5.1 Crystal Amplifier Input Pin (OSC1)
The OSC1 pin is an input to the crystal oscillator amplifier.
10.5.2 Crystal Amplifier Output Pin (OSC2)
The OSC2 pin is the output of the crystal oscillator inverting amplifier.
10.5.3 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.
NOTE: To prevent noise problems, CF should be placed as close to the
CGMXFC pin as possible with minimum routing distances and no routing
of other signals across the CF connection.
MC68HC908AS60 — Rev. 1.0
Technical Data
Clock Generator Module (CGM)
For More Information On This Product,
Go to: www.freescale.com
FREESCALE [ Freescale ]
