Fixed-Point Blockset Release Notes    

Chapter 3
Fixed-Point Blockset 3.0 Release Notes

New Features

This section introduces the new features and enhancements added in the Fixed-Point Blockset 3.0 since the Fixed-Point Blockset 2.0 (Release 11.0).

This section is organized into these subsections:

New Blocks

The Fixed-Point Blockset 3.0 includes the new blocks listed below.

Block Name
Output the absolute value of the input.
Bitwise Operator
Perform the specified bitwise operation on the inputs.
Data Type Propagation
Configure the data type and scaling of the propagated signal based on information from the reference signals.
Dead Zone
Provide a region of zero output.
Dot Product
Generate the dot product.
Gateway In Inherited
Convert a Simulink data type to a Fixed-Point Blockset data type, and inherit the data type and scaling.
Integer Delay
Delay a signal N sample periods.
Look-Up Table Dynamic
Approximate a one-dimensional function using a selected look-up method and a dynamically specified table.
Output the minimum or maximum input value.
Multiport Switch
Switch output between different inputs based on the value of the first input.
Indicate the sign of the input.
Tapped Delay
Delay a scalar signal multiple sample periods, and output all the delayed versions.
Unary Minus
Negate the input.

New Functions

The Fixed-Point Blockset 3.0 includes the new functions listed below.

Function Name
Determine the exponent that gives the best precision fixed-point representation of a value.
Determine the maximum precision available for the fixed-point representation of a value.
Convert Simulink models and subsystems to fixed-point equivalents.
Prepare a Simulink model for more complete conversion to fixed point.
Restore links for fixed-point blocks.

Data Type Support

The Fixed-Point Blockset 3.0 has expanded its data type support:

Data Type and Scaling Inheritance

Many fixed-point blocks support the inheritance of data type and scaling information from other blocks. The two possible inheritance options are:

Increased Speed, Efficiency, and Accuracy

Overflow Logging

Indirect logging of overflows and saturations via percent range error has been replaced by explicit logging.

Simulink Accelerator

You can now use the Simulink Accelerator in conjunction with the Fixed-Point Blockset. However, you cannot log minimum and maximum simulation values or overflows.

Model Parameter Configuration

You can now use the Model Parameter Configuration dialog box to override the Inline parameters option for selected parameters. You access this feature by selecting the Configure button on the Advanced tab of the Simulation Parameters dialog box. Previously, code generation for fixed point blocks required all parameters to be inline, or all parameters to be tunable.

Display of Scaling Information

To significantly improve simulation speed, the scaling information associated with fixed-point blocks is no longer updated. Since this scaling information can become obsolete, you should remove it by running fixpt_clear_tag or slupdate. To view data type and scaling information, you should select Port data types under the model's Format menu.

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