MCF5270 FREESCALE [Freescale Semiconductor, Inc], MCF5270 Datasheet - Page 20

• Manufacturer Part Number: MCF5270
• Description: 32-bit Embedded Controller Division
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Design Recommendations
6.2
6.3
6.4
6.5
6.6
6.7
6.7.1
6.7.1.1
Table 4
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33 µF, .1 µF and .01 µF across each power supply
Place the decoupling caps as close to the pins as possible, but they can be outside the footprint of
the package.
.1 µF and .01 µF at each supply input
Use bus buffers on all data/address lines for all off-board accesses and for all on-board accesses
when excessive loading is expected. See
Use external pull-up resistors on unused inputs. See pin table.
Use a multi-layer board with a separate ground plane.
Place the crystal and all other associated components as close to the EXTAL and XTAL
(oscillator pins) as possible.
Do not run a high frequency trace around crystal circuit.
Ensure that the ground for the bypass capacitors is connected to a solid ground trace.
Tie the ground trace to the ground pin nearest EXTAL and XTAL. This prevents large loop
currents in the vicinity of the crystal.
Tie the ground pin to the most solid ground in the system.
Do not connect the trace that connects the oscillator and the ground plane to any other circuit
element. This tends to make the oscillator unstable.
Tie XTAL to ground when an external oscillator is clocking the device.
shows the behavior of SDRAM signals in synchronous mode.
Power Supply
Decoupling
Buffering
Pull-up Recommendations
Clocking Recommendations
Interface Recommendations
SDRAM Controller
SDRAM Controller Signals in Synchronous Mode
MCF5271 Integrated Microprocessor Hardware Specification, Rev. 1.2
Section 8, “Preliminary Electrical
Characteristics.”
Freescale Semiconductor