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DIGITAL SIGNAL PROCESSING
Let System Generator
Do the Handshaking
You can use the state control capabilities of Xilinx
System Generator for synchronous digital DSP realization.
by T. Justin Campbell
FPGA Programmer
UVM
tcampbel@uvm.edu
If you are a DSP circuit designer, you
should not feel restricted by the basic
Xilinx logic blocks when building your
design. Custom logic in a DSP circuit may
not seem possible within the abstract world
of Xilinx ® System Generator, but on the
contrary, you can easily realize custom logic
by configuring a Xilinx MCode block.
A MATLAB ® M-file from The
MathWorks configures the block to emulate
the algorithm realized in the file. You
can attain custom control – and more
specifically, state machines – with System
Generator through configuration of a
Xilinx black box, with code generated from
Xilinx StateCAD. The VHDL code generated
by StateCAD is emulated within the
Xilinx black box block.
With advanced design and control
logic, synchronization in DSP circuits also
becomes an issue. You can realize handshaking
(the exchange of control and status
information between two blocks) in
System Generator through delays and
enable signals.
78 Xcell Journal Winter 2004