20-101-1246 Rabbit Semiconductor, 20-101-1246 Datasheet - Page 50

• Manufacturer Part Number: 20-101-1246
• Description: CORE MODULE RCM5400W
• Manufacturer: Rabbit Semiconductor

Specifications of 20-101-1246

• Module/board Type: MPU Core Module
• Wireless Frequency: 73.73 MHz
• For Use With/related Products: RCM5400W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 316-1148

4.5 Other Hardware
4.5.1 Clock Doubler
The RCM5400W takes advantage of the Rabbit 5000 microprocessor’s internal clock
doubler. A built-in clock doubler allows half-frequency crystals to be used to reduce
radiated emissions. The 73.73 MHz frequency specified for the RCM5400W is generated
using a 36.864 MHz crystal.
The clock doubler should not be disabled since Wi-Fi operations depend highly on CPU
resources.
4.5.2 Spectrum Spreader
The Rabbit 5000 features a spectrum spreader, which helps to mitigate EMI problems. The
spectrum spreader is on by default, but it may also be turned off or set to a stronger setting.
The spectrum spreader settings may be changed through a simple configuration macro as
shown below.
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1. Select the “Defines” tab from the Dynamic C
2. Normal spreading is the default, and usually no entry is needed. If you need to specify
3. Click
normal spreading, add the line
For strong spreading, add the line
To disable the spectrum spreader, add the line
are in the project file where you defined the macro.
ENABLE_SPREADER=1
ENABLE_SPREADER=2
ENABLE_SPREADER=0
NOTE: Refer to the Rabbit 5000 Microprocessor User’s Manual for more information
NOTE: The strong spectrum-spreading setting is not recommended since it may limit
OK
on the spectrum-spreading setting and the maximum clock speed.
the maximum clock speed or the maximum baud rate. It is unlikely that the strong
setting will be needed in a real application.
to save the macro. The spectrum spreader will now remain off whenever you
Options > Project Options
RabbitCore RCM5400W
menu.