Rabbit 2000 Getting Started - page 8
Getting Started Manual
3
You have a choice of doing your software development in the flash memory or in the static
RAM included on the Jackrabbit board. There are 128K in each memory. Versions of the
Jackrabbit board are available that support only 32K of static RAM. If you use one of
these boards, you must do development in flash memory. The advantage of working in
RAM is to save wear on the flash, which is limited to about 100,000 writes. Note that an
application can only be developed in RAM, but cannot run standalone from RAM after the
programming cable is disconnected. All applications can only run from flash.
When using flash, the compile to a file is followed by a download to the flash. The disad-
vantage of using flash is that interrupts must be disabled for approximately 5 ms whenever
a break point is set in the program. This can crash fast interrupt routines that are running
while you stop at a breakpoint or single-step the program. Flash or RAM is selected on the
Options-Compiler
menu.
Dynamic C provides a number of debugging features. You can single-step your program,
either in C, statement by statement, or in assembly language, instruction by instruction.
You can set breakpoints, where the program will stop, on any statement. You can evaluate
watch expressions. A watch expression is any C expression that can be evaluated in the
context of the program. If the program is at a breakpoint, a watch expression can view any
expression using local or external variables. If the program is running and a call to the
debugger is included in the user’s code (
runwatch();
), it is possible to evaluate watch
expressions using global variables only while the target program continues to run, slowed
down only by the need to refresh a display in response to a
command.