Integrate C/C++ Code Using C Function Blocks

Integrate and call external C/C++ code from a Simulink^® model

Use the C Function block to call external C/C++ code from your model. Use the C Function block to:

Write C code to preprocess data to call a C function. Similarly, you can write C code to postprocess data after calling a C function.
Specify different code for simulation and code generation.
Call multiple C functions defined in your external code.
Initialize and work with persistent data cached in the block.
Allocate and deallocate memory.

To get started by configuring custom code sources in your Simulink model, see Specify and Configure Custom C/C++ Code.

To call simple C code, use the C Caller block. To integrate a dynamic system using C code into your Simulink model, use the S-Function block.

Blocks

C Function

Integrate and call external C/C++ code from a Simulink model (Since R2020a)

Objects

`SymbolSpec`	Query and configure C Function block data symbols (Since R2020a)
`Symbol`	C Function block data symbol (Since R2020a)

Model Settings

Model Configuration Parameters: Simulation Target

Topics

Specify and Configure Custom C/C++ Code
Specify custom C/C++ headers, source files, and libraries, and configure custom code settings for your Simulink model.
Integrate External C/C++ Code into Simulink Using C Function Blocks

Integrate and modify external C Code using C Function blocks.
Interface with C++ Classes Using C Function Block
Use C Function block to interface directly with C++ classes defined in custom code.
Debug Custom C/C++ Code
Debug custom C/C++ code from within Simulink.

Featured Examples

Start and Terminate Actions Within a C Function Block

Use the C Function block to integrate legacy C functions that have start and terminate actions.

Open Script

Call C++ Class Methods Directly from a C Function Block

Call C++ Class Methods Directly From a C Function Block.

Open Script

Call C++ Class Methods Using C-Style Wrapper Function from C Function Block

Use the C Function block to call C++ class methods using a C-style wrapper function.

Open Model

Call Legacy Lookup Table Functions Using C Function Block

Use the C Function block to call legacy C functions that implement N-dimensional table lookups.

Open Script

Use C Function Block Within For Each Subsystem

Use a C Function block within a For Each subsystem. The example passes a vector signal into the For Each subsystem, which repeats execution of the C Function block on each element of the input signal and concatenates the results. The C Function block calls the custom code function customSaturateFcn(), which implements a saturation algorithm and outputs a clipped version of the input signal. A C Caller block with the same settings can also be used in place of a C Function block in a For Each subsystem.

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