DSP56F826 Motorola, DSP56F826 Datasheet - Page 25

• Manufacturer Part Number: DSP56F826
• Description: 16-bit Digital Signal Processor
• Manufacturer: Motorola

3.5.2
The recommended method of connecting an external clock is given in
is connected to XTAL and the EXTAL pin is grounded.
It is possible to instead drive EXTAL with an external clock, though this is not the recommended method.
If you elect to drive EXTAL with an external clock source the following conditions must be met:
Figure 10
the input.
1. XTAL must be completely un-loaded,
2. the maximum frequency of the applied clock must be less than 6MHz.
illustrates how to connect an external clock circuit with a external clock source using EXTAL as
External Clock Source
Figure 10. Connecting an External Clock Signal using EXTAL
Figure 9. Connecting an External Clock Signal using XTAL
Figure 8. External Crystal Oscillator Circuit
EXTAL XTAL
DSP56F826 Preliminary Technical Data
R
z
Crystal Frequency = 4MHz
Connection Clock ( < 6MHz)
External
XTAL
Clock
XTAL
Sample External Crystal
Parameters:
R
No
DSP56F826
DSP56F826
z
= 20 MW
EXTAL
EXTAL
External
V
SS
Figure
9. The external clock source
External Clock Operation
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