Analog Devices Blackfin Getting Started page 46

Evaluation Tools
debugging time. BTC enables real-time data collection and status messag-
ing, eliminating the overhead involved with halting the target application,
getting the desired information, and then restarting the target application.
You can benefit from BTC directly within the IDDE plot window if your
targets support BTC. In this case, the plot window reads the target's mem-
ory contents on a user-defined time interval and upon receipt of the data,
converts them to the desired data type, and updates the plot display for
you to view and analyze immediately.
Statistical Profiling. Statistical profiling allows for a more generalized
form of profiling of which JTAG emulator debugging targets can take
advantage. The debugger can unobtrusively and statically sample the tar-
get processors and then present you with a graphical display of the
resultant samples for review. This enables you to easily and effortlessly
identify where an application is spending most of its time.
Graphical Plotting. VisualDSP++ includes numerous graphical plotting
options, including Line, Constellation, Eye Diagrams, and 3-D Waterfall
plots that help you better visualize, analyze, and understand your data.
The plotting engine can also perform some simple data processing, such as
outputting FFT magnitudes and converting data to dB before displaying
the information.
Profile-Guided Optimization. Profile-Guided Optimization (PGO) is an
iterative compilation approach that uses information from previous com-
pilations to improve the optimizer's decisions on the code being compiled.
Traditionally, a compiler processes each function only once and attempts
to generate code that performs optimally in most cases by making reason-
able default assumptions of the behavior of that code. With PGO, the
compiler makes educated assumptions based on data collected during pre-
vious executions of the generated code and subsequently makes decisions
about the relative importance of parts of the application, rather than sim-
ply using the default behavior. This technique can enable large gains to be
realized in the run-time performance and code density of the program
automatically without additional user effort.
2-8 Getting Started With Blackfin Processors