101-1006 Rabbit Semiconductor, 101-1006 Datasheet - Page 143

• Manufacturer Part Number: 101-1006
• Description: MODULE POWERCORE FLEX 3800
• Manufacturer: Rabbit Semiconductor

Specifications of 101-1006

• Module/board Type: MPU Core Module
• For Use With/related Products: RCM3800
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

B.4.6 Serial Communication
The PowerCore Prototyping Board allows you to access three of the serial ports on the Pow-
erCore module. Table B-2 summarizes the use of the three serial ports.
B.4.6.1 RS-232
RS-232 serial communication on the PowerCore Prototyping Board is supported by an
RS-232 transceiver installed at U2. 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 +3.3 V input becomes approximately
-7 V and 0 V is output as +7 V. The RS-232 transceiver also provides the proper line load-
ing for reliable communication.
RS-232 can be used effectively at the PowerCore module’s maximum baud rate for dis-
tances of up to 15 m.
RS-232 flow control on an RS-232 port is initiated in software using the
serXflowcontrolOn
The locations of the flow control lines are specified using a set of five macros.
User’s Manual
SERX_RTS_PORT—Data register for the parallel port that the RTS line is on (e.g., PGDR).
SERX_RTS_SHADOW—Shadow register for the RTS line's parallel port (e.g., PGDRShadow).
SERX_RTS_BIT—The bit number for the RTS line.
SERX_CTS_PORT—Data register for the parallel port that the CTS line is on (e.g., PCDRShadow).
SERX_CTS_BIT—The bit number for the CTS line.
Table B-2. PowerCore Prototyping Board Serial Ports
Serial Port
function call from
D
E
F
Signal Header
(RJ-45 jack)
J5
J1
J1
RS232.LIB
, where
RabbitNet
RS-232
RS-232
Use
X
is the serial port (E or F).
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