Fixed Point
Within digital hardware, numbers are represented as either fixed-point or floating-point data types. For both of these data types, word sizes are fixed at a set number of bits. However, the dynamic range of fixed-point values is much less than floating-point values with equivalent word sizes. While floating-point processors can greatly simplify the real-time implementation of a system, and effectively approximate real-world numbers, fixed-point processors carry numerous other benefits. Fixed-point processors are generally smaller, consuming less power. They also require less memory and less processor time to perform.
To simulate a model that uses fixed-point numbers, you must install the Fixed-Point Designer™ product. You do not need the Fixed-Point Designer product to edit a model containing fixed-point blocks, or to specify fixed-point data types.
Functions
fixdt | Create Simulink.NumericType object describing a fixed-point or
floating-point data type |
fixptbestexp | Exponent that gives best precision for fixed-point representation of value |
fixptbestprec | Determine maximum precision available for fixed-point representation of value |
Topics
- Specify Fixed-Point Data Types
If you do not have Fixed-Point Designer, you can still inspect and use fixed-point models that others share with you.
- Specify Data Types Using Data Type Assistant
Interactively apply data types, such as integer, fixed-point, and enumerated types, to data items in a model.
- Share Fixed-Point Models
Inspect and use an existing fixed-point model when you do not have Fixed-Point Designer.
- Control Fixed-Point Instrumentation and Data Type Override
If you do not have Fixed-Point Designer, you can work with a model containing Simulink® blocks with fixed-point settings by turning off fixed-point instrumentation and setting data type override to scaled doubles.
- Fixed-Point Numbers
Represent and scale fixed-point number in Simulink.
- Benefits of Using Fixed-Point Hardware
Fixed-point designs can perform faster and consume fewer computing resources than floating-point designs.
- Scaling, Range, and Precision
Learn how fixed-point types are scaled and how to interpret the range and precision of a data type from its scaling.
- Fixed-Point Data in MATLAB and Simulink
Apply fixed-point data types to data in Simulink models and to data in MATLAB® code.
