RabbitCore RCM3305, User Manual

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32 RabbitCore RCM3305/RCM3315
4.2.3 Programming Port
The RCM3305/RCM3315 is programmed either through the serial programming port,
which is accessed using header J1, or through the Ethernet jack. The RabbitLink may be
used to provide a serial connection via the RabbitLink’s Ethernet jack. The programming
port uses the Rabbit 3000’s Serial Port A for communication; Serial Port A is not used
when programming is done over an Ethernet connection via the Dynamic C download
manager or the remote application update. 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 RCM3305/RCM3315 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
RCM3305/RCM3315 onboard peripheral circuits. The serial programming port can be
used to force a hard reset on the RCM3305/RCM3315 by asserting the /RESET_IN signal.
Alternate Uses of the 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.