Xilinx V2.1 - Manual (Page 80)

80 Xilinx Development System
Xilinx System Generator v2.1 Reference Guide
Block Parameters Dialog Box
The block parameters dialog box can be invoked by double-clicking the icon in your
Simulink model.
Figure 3-53: FIR block parameters dialog box
Parameters specific to the block are:
•
Coefficients : vector of filter coefficients; note that these can be evaluated from
a MATLAB workspace variable and may in turn be computed by MATLAB. You
can also refer to examples in the System Generator Tutorial.
•
Coefficient Structure : Xilinx Smart-IP core preferred implementation
depends on the structure of the sequence of filter taps. You can choose one of
these: inferred from coefficients, none, symmetric, negative symmetric, half band,
and interpolate fir.
•
Number of bits per coefficient : Xilinx fixed point parameter.
•
Binary point for coefficients : Xilinx fixed point parameter.
•
Coefficient arithmetic type : Xilinx fixed point parameter.
•
Number of Channels : One to eight, inclusive. For multi-channel filters,
polyphase behavior is not supported, i.e. the filter must be single rate. The core,
which processes the channels serially, will be overclocked by the System
Generator by a factor equaling the number of channels so as to provide the
necessary throughput. To reduce control logic overhead, the block requires that
the valid bits match on all inputs.