User`s manual

User’s Manual 27
4.2 Serial Communication
The RCM3400 board does not have any serial transceivers directly on the board. How-
ever, an Ethernet or other serial interface may be incorporated on the board the RCM3400
is mounted on. For example, the Prototyping Board has RS-232, RS-485, IrDA, and
Ethernet transceiver chips.
4.2.1 Serial Ports
There are five serial ports designated as Serial Ports A, C, D, E, and F. All five 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 application development has been completed and
the RCM3400 is operating in the Run Mode.
Serial Port B is used by the A/D converter, and is not available for other use off the
RCM3400.
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 SDLC/HDLC serial ports. The IrDA proto-
col is also supported in SDLC format by these two ports.
4.2.2 Programming Port
The RCM3400 serial programming port is accessed via the 10-pin header labeled J2 on
the Prototyping Board or over an Ethernet connection via the RabbitLink EG2110. The
programming port uses the Rabbit 3000’s Serial Port A for communication. Dynamic C
uses the programming port to download and debug programs.
The programming port is also used for the following operations.
• Cold-boot the Rabbit 3000 on the RCM3400 after a reset.
• Remotely download and debug a program over an Ethernet connection using the
RabbitLink EG2110.
• Fast copy designated portions of flash memory from one Rabbit-based board (the
master) to another (the slave) using the Rabbit Cloning Board.
If the Prototyping Board is not used, programming must be initiated through the mother-
board to which the RCM3400 module is plugged in to since the Serial Port A (PC6 and
PC7), SMODE0, SMODE1, and /RESET_IN are available on headers J1 and J2 (see
Table 2).