Xilinx V2.1 - Manual (Page 74)

74 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 3-49: DDS block parameters dialog box
Parameters specific to the DDS block are:
•
Function : specifies the block output to be sine, cosine, or both.
•
Negative Sine : when checked, the sine output is negated.
•
Negative Cosine : when checked, the cosine output is negated.
•
Output Width : number of bits in the output signal; value must be between 4
and 32 inclusive.
•
Lookup Table Input Width : specifies the number of address bits into the
Sin/Cos Lookup Table; value must be at least 3. It cannot exceed the lesser of the
accumulator width and 16 (if block RAM is used), or 10 (if distributed RAM is
used).