dsp56004 Freescale Semiconductor, Inc, dsp56004 Datasheet - Page 77

• Manufacturer Part Number: dsp56004
• Description: Symphonytm Audio Dsp Family 24-bit Digital Signal Processors
• Manufacturer: Freescale Semiconductor, Inc

ELECTRICAL DESIGN CONSIDERATIONS
MOTOROLA
Use the following list of recommendations to assure correct DSP operation:
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This device contains protective circuitry to guard against
damage due to high static voltage or electrical fields.
However,
application of any voltages higher than maximum rated
voltages to this high-impedance circuit. Reliability of
operation is enhanced if unused inputs are tied to an
appropriate logic voltage level (e.g., either GND or V
Provide a low-impedance path from the board power supply to each V
pin on the DSP, and from the board ground to each GND pin.
Use at least four 0.01–0.1 F bypass capacitors positioned as close as
possible to the four sides of the package to connect the V
to GND.
Ensure that capacitor leads and associated printed circuit traces that
connect to the chip V
lead.
Use at least a four-layer Printed Circuit Board (PCB) with two inner layers
for V
Because the DSP output signals have fast rise and fall times, PCB trace
lengths should be minimal. This recommendation particularly applies to
the address and data buses as well as the IRQA, IRQB, and NMI pins.
Maximum Printed Circuit Board (PCB) trace lengths on the order of
6 inches are recommended.
Consider all device loads as well as parasitic capacitance due to PCB
traces when calculating capacitance. This is especially critical in systems
with higher capacitive loads that could create higher transient currents in
the V
All inputs must be terminated (i.e., not allowed to float) using CMOS
levels, except as noted in Section 1.
Take special care to minimize noise levels on the V
If multiple DSP56004 devices are on the same board, check for cross-talk
or excessive spikes on the supplies due to synchronous operation of the
devices.
Freescale Semiconductor, Inc.
CC
CC
For More Information On This Product,
and GND.
and GND circuits.
normal
Go to: www.freescale.com
DSP56004/D, Rev. 3
precautions
CC
CAUTION
and GND pins are less than 0.5 in per capacitor
are
advised
Electrical Design Considerations
CCP
to
CC
and GND
Design Considerations
).
avoid
CC
power source
P
pins.
CC
4-3