Data Type Support (DSP Blockset)

DSP Blockset

Effects of Enabling and Disabling Boolean Support

By default, Simulink enables Boolean support. When you leave Boolean support enabled, all Boolean-supporting output ports always output the Boolean data type.

In some cases, you may want to override the Simulink default and disable Boolean support. For example, you may have a model that you created before Boolean support existed. Leaving the Boolean support enabled in this model may cause some blocks that used to output the double-precision data type to output the Boolean data type. If the introduction of the Boolean data type breaks your model, you can fix the problem by disabling Boolean support.

The following table describes the effects of enabling and disabling Boolean support. Note that when you disable Boolean support, some Boolean-supporting output ports output double-precision data.

Type of Boolean-Supporting Output Port
Effect of Enabling Boolean Support (Default)
Effect of Disabling Boolean Support

On a block with at least one input port

Did not support the Boolean data type in versions of the DSP Blockset before Version 5.0

(For example, the Edge Detector block)
Output is always Boolean, regardless of the input data type.

When input is double precision, the output is also double precision.

When input is not double precision, the output is Boolean.

With a corresponding block parameter for setting output data type to Logical or Boolean (for example, in the N-Sample Enable block)
Output is always Boolean, regardless of whether you set the output port to Logical or Boolean.

When set to Logical, the output is double precision.

When set to Boolean, the output is Boolean.

Type of Boolean-Supporting Output Port	Effect of Enabling Boolean Support (Default)	Effect of Disabling Boolean Support
On a block with at least one input port Did not support the Boolean data type in versions of the DSP Blockset before Version 5.0 (For example, the Edge Detector block)	Output is always Boolean, regardless of the input data type.	When input is double precision, the output is also double precision. When input is not double precision, the output is Boolean.
With a corresponding block parameter for setting output data type to Logical or Boolean (for example, in the N-Sample Enable block)	Output is always Boolean, regardless of whether you set the output port to Logical or Boolean.	When set to Logical, the output is double precision. When set to Boolean, the output is Boolean.

Lists of Blocks Supporting Boolean Inputs or Outputs Steps to Disabling Boolean Support