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RabbitCore RCM3200
4.2.3 Serial Programming Port
The RCM3200 serial programming port is accessed using header J3 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 RCM3200 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.
In addition to Serial Port A, the Rabbit 3000 startup-mode (SMODE0, SMODE1), status,
and reset pins are available on the programming port.
The two startup mode pins determine what happens after a reset—the Rabbit 3000 is
either cold-booted or the program begins executing at address 0x0000.
The status pin is used by Dynamic C to determine whether a Rabbit microprocessor is
present. The status output has three different programmable functions:
1. It can be driven low on the first op code fetch cycle.
2. It can be driven low during an interrupt acknowledge cycle.
3. It can also serve as a general-purpose CMOS output.
The /RESET_IN pin is an external input that is used to reset the Rabbit 3000 and the
RCM3200/RCM3220 onboard peripheral circuits. The serial programming port can be
used to force a hard reset on the RCM3200/RCM3220 by asserting the /RESET_IN signal.
Alternate Uses of the Serial Programming Port
All three clocked Serial Port A signals are available as
a synchronous serial port
an asynchronous serial port, with the clock line usable as a general CMOS I/O pin
The programming port may also be used as a serial port once the application is running.
The SMODE pins may then be used as inputs and the status pin may be used as an output.
Refer to the Rabbit 3000 Microprocessor User’s Manual for more information.