Simulink Fixed Point 6.2

Simulating Fixed-Point Designs

Once a model has been configured with fixed-point data types, you can simulate its performance to explore design implementation tradeoffs between limited range and precision for fixed-point embedded systems. Simulink Fixed Point has debugging capabilities that let you quickly switch to a floating-point representation of your model to perform benchmarking of the design, identify modeling errors, and determine ideal minimum, maximum, and overflow values.

Using automatic scaling features, you can access these values and change the scaling of signals, optimizing precision while ensuring that their range is covered. Data type ranges can be specified using design minimums and maximums or by using simulation results. Output data types can lock their output scaling to prevent them from being autoscaled. Otherwise, scaling is optimized automatically.

Sharing Models with Fixed-Point Data Types

Simulink Fixed Point makes it easy to share models that include fixed-point data types. Because data types can be globally overridden, you can switch between fixed-point and floating-point representations without changing the model’s structure. The model remains compatible with Simulink, Stateflow, Signal Processing Blockset, Communications Blockset™, Video and Image Processing Blockset™, and other products supported by Simulink Fixed Point. As a result, you can use one model throughout your design process. You can keep models in sync, reuse the same models for multiple purposes, and circle back in the development process without breaking the model.

The Fixed-Point Advisor (above right), which provides an initial fixed-point design from a floating-point model. The Fixed-Point Tool (above left) provides capabilities to produce a more optimized scaling using global data type override, logged min/max and overflow values, automatic scaling, and comparison of floating-point to fixed-point signal responses. Click on image to see enlarged view.