mc56f8335 Freescale Semiconductor, Inc, mc56f8335 Datasheet - Page 34

• Manufacturer Part Number: mc56f8335
• Description: 16-bit Digital Signal Controller
• Manufacturer: Freescale Semiconductor, Inc

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.
Note:
3.2.3
The recommended method of connecting an external clock is illustrated in
source is connected to XTAL and the EXTAL pin is grounded.
external clock source as well.
34
CLKMODE = 0
2 Terminal
CL1
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)
The OCCS_COHL bit must be set to 0 when a ceramic resonator 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.
External Clock Source
EXTAL XTAL
CL1
R
EXTAL
z
R
Figure 3-2 Connecting to a Crystal Oscillator
CL2
Figure 3-3 Connecting a Ceramic Resonator
Z
Resonator Frequency = 4 - 8MHz (optimized for 8MHz)
XTAL
Crystal Frequency = 4 - 8MHz (optimized for 8MHz)
CL2
EXTAL
3 Terminal
C1
EXTAL XTAL
56F8335 Technical Data, Rev. 5
R
Z
R
XTAL
z
C2
Sample External Ceramic Resonator Parameters:
R
z
Sample External Crystal Parameters:
R
Note: If the operating temperature range is limited to
below 85
= 750 KΩ
z
= 750 KΩ
o
C (105
Set OCCS_COHL bit high when using an
CLKMODE = 0
o
C junction), then R
Figure
3-4. The external clock
Freescale Semiconductor
z
= 10 Meg Ω
Figure
Preliminary
3-3.