MC56F8345 Freescale Semiconductor, Inc, MC56F8345 Datasheet - Page 37

• Manufacturer Part Number: MC56F8345
• Description: 56f8300 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

The crystal and associated components should be mounted as near as possible to the EXTAL and XTAL
pins to minimize output distortion and start-up stabilization time.
Note:
3.2.2
It is also possible to drive the internal oscillator with a ceramic resonator, assuming the overall system
design can tolerate the reduced signal integrity. A typical ceramic resonator circuit is shown in
Refer to the supplier’s recommendations when selecting a ceramic resonator and associated components.
The resonator and components should be mounted as near as possible to the EXTAL and XTAL pins.
Freescale Semiconductor
Preliminary
CLKMODE = 0
The OCCS_COHL bit must be set to 1 when a crystal oscillator is used. The reset condition on the
OCCS_COHL bit is 0. Please see the COHL bit in the Oscillator Control (OSCTL) register, discussed
in the 56F8300 Peripheral User’s Manual.
Ceramic Resonator (Default)
CL1
EXTAL
R
Figure 3-2 Connecting to a Crystal Oscillator
Z
XTAL
Crystal Frequency = 4 - 8MHz (optimized for 8MHz)
CL2
EXTAL
56F8345 Technical Data, Rev. 17
R
Z
XTAL
Sample External Crystal Parameters:
R
Note: If the operating temperature range is limited to
below 85
z
= 750 KΩ
o
C (105
o
C junction), then R
z
External Clock Operation
= 10 Meg Ω
Figure
3-3.
37