mcf5274l Freescale Semiconductor, Inc, mcf5274l Datasheet - Page 34

• Manufacturer Part Number: mcf5274l
• Description: Mcf5275 Integrated Microprocessor Family Hardware
• Manufacturer: Freescale Semiconductor, Inc

Design Recommendations
6
6.1
6.2
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Use a 4-layer printed circuit board with the VDD and GND pins connected directly to the power
and ground planes for the MCF5275.
See application note AN1259 System Design and Layout Techniques for Noise Reduction in
MCU-Based Systems.
Match the PC layout trace width and routing to match trace length to operating frequency and
board impedance. Add termination (series or therein) to the traces to dampen reflections.
Increase the PCB impedance (if possible) keeping the trace lengths balanced and short. Then do
cross-talk analysis to separate traces with significant parallelism or are otherwise "noisy". Use 6
mils trace and separation. Clocks get extra separation and more precise balancing.
33uF, 0.1uF and 0.01uF across each power supply
Design Recommendations
Layout
Power Supply
Inputs
driven
high or
low as
needed
MCF5275 Integrated Microprocessor Family Hardware Specification, Rev. 1.1
Figure 2. MCF5275 Recommended Reset Configuration Circuit
74HC244
VDD/VSS
Preliminary
OE
D16
D17
D18
D19
D21
D24
D25
D26
RSTOUT
RCON
CLKMOD0
CLKMOD1
JTAG_EN
MCF5275
Freescale Semiconductor