101-0680 Rabbit Semiconductor, 101-0680 Datasheet - Page 121

• Manufacturer Part Number: 101-0680
• Description: KIT DEV RABBITCORE/RCM3700
• Manufacturer: Rabbit Semiconductor
• Series: RabbitCore 3000r
• Type: MPU Moduler

Specifications of 101-0680

• Rohs Status: RoHS non-compliant
• Contents: RabbitCore Module, Dev. Board, AC Adapter, Cable and Dynamic C® CD-Rom
• Processor To Be Evaluated: RCM3700
• Data Bus Width: 8 bit
• Interface Type: Ethernet
• For Use With/related Products: RCM3700
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 316-1038

B.2.5 Serial Communication
RCM3720 Prototyping Boards sold before 2007 had no RS-232 chip installed, and so no
RS-232 communication was possible. An optional through-hole RS-232 chip could be
installed at U1 or a surface-mount RS-232 chip could be installed at U3. Five correspond-
ing through-hole or surface-mount capacitors must also be installed. Figure B-16 shows
where to install the RS-232 chip and its associated capacitors for the two options.
Figure B-16. Locations Where to Install RS-232 Chip and Capacitors
NOTE: Only one RS-232 circuit needs to be stuffed.
Rabbit offers the through-hole RS-232 chip and its associated capacitors for sale in a sub-
assembly with some other parts (part number 151-0150). Contact your Rabbit sales repre-
sentative or authorized distributor for more information.
RS-232 serial communication on the RCM3720 Prototyping Board is supported by the
RS-232 transceiver installed at U3. This transceiver provides the voltage output, slew rate,
and input voltage immunity required to meet the RS-232 serial communication protocol.
Basically, the chip translates the Rabbit 3000’s signals to RS-232 signal levels. Note that
the polarity is reversed in an RS-232 circuit so that a +5 V output becomes approximately
-10 V and 0 V is output as +10 V. The RS-232 transceiver also provides the proper line
loading for reliable communication.
RabbitCore RCM3700 User’s Manual
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