DSP Blockset 4.1 Release Notes (DSP Blockset Release Notes)

DSP Blockset Release Notes

Major Individual Block Enhancements

The following sections summarize the major individual block enhancements for DSP Blockset 4.1:

FFT Block

You can now set the block to compute twiddle factors by table lookup or by calling trigonometric math library functions. In table lookup mode, the block precomputes and stores a table that you can optimize for memory or speed. For an N-point FFT, a table optimized for speed yields a length-3N/4 table, and a table optimized for memory yields a length-N/4 table.
A new option lets you set the block to output in bit-reversed or linear order. Outputting in bit-reversed order reduces computation time by eliminating the output data descrambling step.
The block processes real-valued inputs using more efficient algorithms.
The block generates smaller Real-Time Workshop C code with improved run-time efficiency through use of in-place algorithms.
The block now supports single-precision (32-bit) floating-point input and output signals (in table lookup mode) for both simulation and Real-Time Workshop C code generation.

For more information, see the FFT block reference page.

IFFT Block

You can now set the block's twiddle factor computation method as in the FFT block (see the earlier FFT block enhancement description).
A new option lets you provide inputs in both linear and bit-reversed order. Using inputs in bit-reversed order reduces block computation time by eliminating the initial input data scrambling step.
You can now explicitly specify conjugate-symmetric input signals to significantly increase processing efficiency and to get a real-valued output signal.
You can now skip normalization by the IFFT length, N, when you do not need to output a normalized signal, increasing processing efficiency.
The block generates smaller Real-Time Workshop C code with improved run-time efficiency through use of in-place algorithms.
The block now supports single-precision (32-bit) floating-point input and output signals (in table lookup mode) for both simulation and Real-Time Workshop C code generation.

For more information, see the IFFT block reference page.

Magnitude FFT Block

You can now set the block to compute the magnitude FFT or magnitude squared FFT
The block uses the new, more efficient FFT block algorithms.

For more information, see the Magnitude FFT block reference page.

Overlap-Add FFT Filter and Overlap-Save FFT Filter Blocks

By using the enhanced FFT and IFFT blocks, the Overlap-Add FFT Filter and Overlap-Save FFT Filter blocks are more efficient. (Both blocks now skip data descrambling and scrambling operations by processing data in bit-reversed order, and use specialized, more efficient algorithms for real-valued input signals.)

Random Source Block

You can now set the repeatability of the block output to Not repeatable, Repeatable, or Specify seed. The default mode is Not repeatable, so that when you add new Random Source blocks from the block library to a model, the blocks automatically generate different outputs (without requiring you to specify a seed).
The block now uses Simulink run-time parameters, greatly enhancing its Real-Time Workshop generated C code (see Enhancements to Blocks Implemented with S-Functions).

Sine Wave Block

You can now optimize the Sine Wave block's table lookup computation method for speed or memory. For speed optimization, the block uses a full-length table, while for memory optimization, it uses a 1/4-length table.

Unwrap Block

You can now set the Unwrap block to phase unwrap across successive inputs for both frame-based and sample-based input signals.

Window Function Block

The Window Function block now generates smaller, more efficient Real-Time Workshop C code by using run-time parameters (see Enhancements to Blocks Implemented with S-Functions).
The block now supports single-precision (32-bit) floating-point input and output signals.

New Digital Filter Design Block Blocks with Enhanced Data Type Support