dsp56800eerm Freescale Semiconductor, Inc, dsp56800eerm Datasheet - Page 40

• Manufacturer Part Number: dsp56800eerm
• Description: 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

crystal parameters determine the component values required to provide maximum stability and reliable
start-up. 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.
Note:
40
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 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 Manual.
EXTAL XTAL
CL1
R
z
EXTAL XTAL
CL2
Figure 3-2 Connecting to a Crystal Oscillator
R
Figure 3-3 Connecting a Ceramic Resonator
z
Resonator Frequency = 4 - 8MHz (optimized for 8MHz)
Crystal Frequency = 4 - 8MHz (optimized for 8MHz)
CL2
EXTAL XTAL
C1
3 Terminal
EXTAL XTAL
56F8357 Technical Data, Rev. 15
R
R
z
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
CLKMODE = 0
o
C junction), then R
Freescale Semiconductor
z
= 10 Meg Ω
Figure
Preliminary
3-3.