MC68HC908GP32_08 Datasheet, PDF (69/266 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

SIMOSCEN
OSCSTOPENB
(FROM CONFIG)
I/O Signals
OSC1
RB
X1
C1
CGMXCLK
OSC2
CGMXFC
10 kΩ
RS
0.033 µF
C2
0.01 µF
V_SSA
V_DDA
V_DD
CBYP
0.1 µF
Note: Filter network in box can be replaced with a 0.47µF capacitor, but will degrade stability.
Figure 5-2. CGM External Connections
5.4 I/O Signals
The following paragraphs describe the CGM I/O signals.
5.4.1 Crystal Amplifier Input Pin (OSC1)
The OSC1 pin is an input to the crystal oscillator amplifier.
5.4.2 Crystal Amplifier Output Pin (OSC2)
The OSC2 pin is the output of the crystal oscillator inverting amplifier.
5.4.3 External Filter Capacitor Pin (CGMXFC)
The CGMXFC pin is required by the loop filter to filter out phase corrections. An external filter network is
connected to this pin. (See Figure 5-2.)
NOTE
To prevent noise problems, the filter network should be placed as close to
the CGMXFC pin as possible, with minimum routing distances and no
routing of other signals across the network.
MC68HC908GP32 Data Sheet, Rev. 10
Freescale Semiconductor
69