101-1028 Rabbit Semiconductor, 101-1028 Datasheet - Page 122

• Manufacturer Part Number: 101-1028
• Description: MODULE RABBITCORE RCM3750
• Manufacturer: Rabbit Semiconductor

Specifications of 101-1028

• Module/board Type: MPU Core Module
• For Use With/related Products: RCM3750
• Lead Free Status / RoHS Status: Vendor undefined / Vendor undefined

B.2.5 Serial Communication
As shipped, the RCM3720 Prototyping Board has no RS-232 chip installed, and so no
RS-232 communication is possible. An optional through-hole RS-232 chip may be
installed at U1 or a surface-mount RS-232 chip may be installed at U3. Five correspond-
ing through-hole or surface-mount 0.1 µF 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 Semiconuctor offers the through-hole RS-232 chip and 0.1 µF capacitors for sale in
a subassembly with some other parts (part number 151-0082). Contact your Rabbit Semi-
conuctor sales representative or authorized distributor for more information.
RS-232 serial communication on the RCM3720 Prototyping Board is supported by the
RS-232 transceiver you installed at U1 or U3. This transceiver provides the voltage out-
put, slew rate, and input voltage immunity required to meet the RS-232 serial communica-
tion 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.
116
RabbitCore RCM3750