20-101-1306 Rabbit Semiconductor, 20-101-1306 Datasheet - Page 38

• Manufacturer Part Number: 20-101-1306
• Description: CORE MODULE RCM5750
• Manufacturer: Rabbit Semiconductor
• Type: Serial to Ethernetr

Specifications of 20-101-1306

• Module/board Type: MPU Core Module
• Number Of I/os: 32
• Ethernet Connection Type: 10/100 Base-T
• Memory Type: Flash
• Operating Voltage: 3.3 V
• Operating Current: 70 mA
• Operating Temperature Range: - 40 C to + 85 C
• Board Size: 30 mm x 51 mm x 3 mm
• Product: Modules
• For Use With/related Products: RCM5750
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 316-1183

4.3.1 Standalone Operation of the RCM5700/RCM6700
The RCM5700/RCM6700 must be programmed via the Interface Board or via a similar arrange-
ment on a customer-supplied board. Once the MiniCore has been programmed successfully, reset
the MiniCore. The MiniCore may be reset by cycling power off/on or by pressing the
ton on the Interface Board. The jumper across pins 1–2 on header JP1 on the Interface Board must
be removed in order for the MiniCore to operate in the Run Mode after it is reset. The MiniCore
module may now be removed from the Interface Board for end-use installation.
4.4 Other Hardware
4.4.1 Clocks
The RCM5700 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
50.0 MHz frequency specified for the RCM5700 model is generated using a 25.0 MHz crystal.
The RCM5700 requires that the clock doubler remain enabled for proper Ethernet operation.
The RCM6700 requires that the clock doubler remain disabled, but takes advantage of the Rabbit
6000 microprocessor's internal PLL, providing clock speeds up to 187.5 MHz.
4.4.2 Spectrum Spreader
The Rabbit 5000/6000 features a spectrum spreader, which helps to mitigate EMI problems. The
spectrum spreader is on by default on the RCM5700, but is off on the RCM6700 because of its
115 MHz maximum clock limitation. It may also be turned off or set to a stronger setting. The
means for doing so is through a simple configuration macro as shown below.
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 normal
3. Click
MiniCore RCM5700/RCM6700 User’s Manual
spreading, add the line
For strong spreading, add the line
To disable the spectrum spreader, add the line
whenever a program is compiled using this project file.
ENABLE_SPREADER=1
ENABLE_SPREADER=2
ENABLE_SPREADER=0
CAUTION: Power to the Interface Board or other boards should be disconnected when removing
NOTE: The strong spectrum-spreading setting is not recommended since it may limit the maxi-
mum clock speed or the maximum baud rate. It is unlikely that the strong setting will be used in a
real application.
NOTE: Refer to the Rabbit 5000 Microprocessor User’s Manual or the Rabbit 6000 Micropro-
cessor User’s Manual for more information on the spectrum-spreading setting and the maximum
clock speed.
OK
or installing your RCM5700/RCM6700 module to protect against inadvertent shorts across the
pins or damage to the MiniCore if the pins are not plugged in correctly. Do not reapply power
until you have verified that the MiniCore module is plugged in correctly.
to save the macro. The spectrum spreader will be set according to the macro value
rabbit.com
Options > Project Options
menu.
RESET
but-
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