RabbitCore RCM3305, User Manual

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30 RabbitCore RCM3305/RCM3315
4.2 Serial Communication
The RCM3305/RCM3315 does not have any serial transceivers directly on the board.
However, a serial interface may be incorporated into the board the RCM3305/RCM3315
is mounted on. For example, the Prototyping Board has RS-232 and RS-485 transceiver
chips.
4.2.1 Serial Ports
There are six serial ports designated as Serial Ports A, B, C, D, E, and F. All six serial
ports can operate in an asynchronous mode up to the baud rate of the system clock divided
by 8. An asynchronous port can handle 7 or 8 data bits. A 9th bit address scheme, where
an additional bit is sent to mark the first byte of a message, is also supported.
Serial Port A is normally used as a programming port, but may be used either as an asyn-
chronous or as a clocked serial port once the RCM3305/RCM3315 has been programmed
and is operating in the Run Mode.
Serial Port B is used to communicate with the serial flash on the RCM3305/RCM3315 and
is not available for other use.
Serial Ports C and D can also be operated in the clocked serial mode. In this mode, a clock
line synchronously clocks the data in or out. Either of the two communicating devices can
supply the clock.
Serial Ports E and F can also be configured as HDLC serial ports. The IrDA protocol is
also supported in SDLC format by these two ports.