Compare System Target File Support Across Products

When you select a system target file (such as grt.tlc), the selection defines the run-time environment and the code generation features. Identify the system target file features that match your code generation workflow goals.

The code generator uses the system target file to produce code intended for execution on certain target hardware or on a certain operating system. The system target file invokes other run-time environment-specific files. For more information on configuring model code generation parameters for target hardware, see Configure Run-Time Environment Options.

Different types of system target files support a selection of generated code features. In the system target file, the value of the CodeFormat TLC variable and corresponding rtwgensettings.DerivedFrom field value identify the system target file type and generated code features. These selections apply your code generation control decisions at several points in the code generation process. Your selections include whether and how the model build generates:

  • Certain data structures (for example, SimStruct or rtModel)

  • Static or dynamic memory allocation code

  • Calling interface for generated model functions

For custom system target file development, the CodeFormat value differs among code generation targets:

  • If the system target file does not include a value for the CodeFormat TLC variable, the default value is RealTime for generic real-time target (GRT). The corresponding rtwgensettings.DerivedFrom field value is grt.tlc (default value).

  • If you are developing a custom system target file and you have Embedded Coder software, consider setting the CodeFormat TLC variable value to Embedded-C for embedded real-time target (ERT). The corresponding rtwgensettings.DerivedFrom field value is ert.tlc. The ERT system target file supports more generated code features than the GRT system target file.

This example shows how the value for the CodeFormat TLC variable and corresponding rtwgensettings.DerivedFrom field value are set in ert.tlc.

%assign CodeFormat = "Embedded-C"

/%
  BEGIN_RTW_OPTIONS
  rtwgensettings.DerivedFrom = 'ert.tlc';
  END_RTW_OPTIONS
%/

Note

Use the value for the CodeFormat TLC variable with its corresponding rtwgensettings.DerivedFrom field value to generate code for the model. If you do not select a value explicitly, the default values correspond. For more information, see System Target File Structure.

For a description of the optimized call interface generated by default for the GRT and ERT system target files, see Configure Code Generation for Model Entry-Point Functions.

Code generation with the GRT and ERT system target files uses the real-time model data structure (rtModel). This structure encapsulates model-specific information in a much more compact form than the simulation structure, SimStruct. Many efficient features of generated code depend on generation of rtModel rather than SimStruct, including:

  • Integer absolute and elapsed timing services

  • Independent timers for asynchronous tasks

  • Generation of improved C API code for signal, state, and parameter monitoring

  • Pruning the data structure to minimize its size (ERT-derived system target files only)

For a description of the rtModeldata structure, see Use the Real-Time Model Data Structure.

Compare Product System Target Files

You can select from a range of system target files by using the System Target File Browser. This selection lets you experiment with configuration options and save your model with different configurations.

You cannot build or generate code for non-GRT system target files, unless you have the required software on your system. For example, you require Embedded Coder® for ERT system target files, Simulink® Desktop Real-Time™ for SLDRT system target files, and so on.

Selecting a system target file for your model selects either the toolchain approach or the template makefile approach for build process control. For more information about these approaches, see Choose Build Approach and Configure Build Process.

System Target Files Available from System Target File Browser

Supported System Target File

File Names

Reference

Embedded Coder (for PC or UNIX® platforms)

ert.tlc
ert_shrlib.tlc

Configure a System Target File (Embedded Coder)

Create Visual C++® Solution File for Embedded Coder

ert.tlc

(Requires RTW.MSVCBuild as TMF. See note.)

Configure a System Target File (Embedded Coder)

Embedded Coder for AUTOSAR

autosar.tlc

Develop a Model that Complies with the AUTOSAR Standard (Embedded Coder)

Generic Real-Time (for PC or UNIX platforms)

grt.tlc

Compare Generated Code Features by STF

Create Visual C++ Solution File

grt.tlc

(Requires RTW.MSVCBuild as TMF. See note.)

Compare Generated Code Features by STF

Rapid Simulation (default for PC or UNIX platforms)

rsim.tlc

Accelerate, Refine, and Test Hybrid Dynamic System on Host Computer by Using RSim System Target File

Rapid Simulation for LCC compiler

rsim.tlc

Accelerate, Refine, and Test Hybrid Dynamic System on Host Computer by Using RSim System Target File

Rapid Simulation for UNIX platforms

rsim.tlc

Accelerate, Refine, and Test Hybrid Dynamic System on Host Computer by Using RSim System Target File

Rapid Simulation for Visual C++ compiler

rsim.tlc

Accelerate, Refine, and Test Hybrid Dynamic System on Host Computer by Using RSim System Target File

S-Function for PC or UNIX platforms

rtwsfcn.tlc

Accelerate Simulation, Reuse Code, or Protect Intellectual Property by Using S-Function Target

S-Function for LCC

rtwsfcn.tlc

Accelerate Simulation, Reuse Code, or Protect Intellectual Property by Using S-Function Target

S-Function for UNIX platforms

rtwsfcn.tlc

Accelerate Simulation, Reuse Code, or Protect Intellectual Property by Using S-Function Target

S-Function for Visual C++ compiler

rtwsfcn.tlc

Accelerate Simulation, Reuse Code, or Protect Intellectual Property by Using S-Function Target

ASAM-ASAP2 Data Definition

asap2.tlc

Export ASAP2 File for Data Measurement and Calibration

Simulink Desktop Real-Time

sldrt.tlc
sldrtert.tlc

Set External Mode Code Generation Parameters (Simulink Desktop Real-Time)

Simulink Real-Time™

slrt.tlc

Simulink Real-Time Options Pane (Simulink Real-Time)

Note

To create and build a Visual C++ Solution (.sln) file with Debug configuration, select RTW.MSVCBuild in the Template makefile field.

Compare Code Styles and STF Support

The code generator produces two styles of code. One code style is suitable for rapid prototyping (and simulation by using code generation). The other style is suitable for embedded applications. This table maps system target files to corresponding code styles.

Code Styles Listed by System Target File 

System Target File

Code Style

Purpose

Embedded Coder embedded real-time (ERT)

Embedded

A starting point for embedded application development of C/C++ generated code.

Simulink Coder™ generic real-time (GRT)

Rapid prototyping

A starting point for creating a rapid prototyping target hardware that does not use real-time operating system tasking primitives and for verifying the generated C/C++ code on your desktop computer.

Rapid simulation (RSim)

Rapid prototyping

Provides non-real-time simulation on your desktop computer and a high-speed or batch simulation tool.

S-function

Rapid prototyping

Creates a C MEX S-function for simulation within another Simulink model.

Simulink Desktop Real-Time

Rapid prototyping

Runs a model in real time at interrupt level while your desktop computer runs Microsoft® Windows® in the background.

Simulink Real-Time

Rapid prototyping

Runs a model in real time on a desktop computer running the Simulink Real-Time kernel.

Third-party vendors supply additional system target files to support code generation for their products. For more information about third-party products, see the vendor website or the MathWorks Connections program web page: https://www.mathworks.com/products/connections.

Compare Generated Code Features by Product

The code generation process for real-time system target files (such as GRT) provides many embedded code optimizations. Selecting an ERT-based system target file offers more extensive features than GRT. The system target file selection determines the available features for the code generation product. As you select the code generation target that matches your development process, use this table to compare code generation features available with Simulink Coder and features available with Embedded Coder.

Compare Code Generation Features for Simulink Coder Versus Embedded Coder

Feature

Simulink Coder

Embedded Coder

rtModel data structure

  • Full rtModel structure generated

  • GRT variable declaration: rtModel_model model_M_;

  • rtModel is optimized for the model

  • Optional suppression of error status field and data logging fields

  • ERT variable declaration: RT_MODEL_model model_M_;

Custom storage classes (CSCs)

Code generation ignores CSCs. Objects are assigned a CSC default to Auto storage class.

Code generation with CSCs is supported

HTML code generation report

Basic HTML code generation report

Enhanced report with additional detail and hyperlinks to the model

Symbol formatting

Symbols (for signals, parameters, and so on) are generated in accordance with hard-coded default

Detailed control over generated symbols

User-defined maximum identifier length for generated symbols

Supported

Supported

Generation of terminate function

Generated

Option to suppress the terminate function

Combined output/update function

Separate output/update functions are generated

Option to generate combined output/update function

Optimized data initialization

Not available

Options to suppress generation of unnecessary initialization code for zero-valued memory, I/O ports, and so on

Comments generation

Basic options to include or suppress comment generation

Options to include Simulink block descriptions, Stateflow® object descriptions, and Simulink data object descriptions in comments

Module Packaging Features (MPF)

Not supported

Extensive code customization features See Control Data Type Names in Generated Code (Embedded Coder) and MPT Data Object Properties (Embedded Coder).

System target file-optimized data types header file

Requires full tmwtypes.h header file

Generates optimized rtwtypes.h header file, including definitions required by the system target file

User-defined types

User-defined types default to base types in code generation

User-defined data type aliases are supported in code generation

Rate grouping

Not supported

Supported

Auto-generation of main program module

Not supported. Static main program module is provided.

Automated and customizable generation of main program module is supported (static main program also available)

Reusable (multi-instance) code generation

Option to generate reusable code with dynamic memory allocation

Option to generate reusable code with static or dynamic memory allocation

Software constraint options

Support for floating-point, complex, and nonfinite numbers is enabled

Options to enable or disable support for floating-point, complex, and nonfinite numbers

Application life span

Defaults to inf

User-specified. Determines most efficient word size for integer timers

Software-in-the-loop (SIL) testing

Model reference simulation target can be used for SIL testing

Additional SIL testing support by using auto-generation of SIL block

ANSI®-C/C++ code generation

Supported

Supported

ISO®-C/C++ code generation

Supported

Supported

GNU®-C/C++ code generation

Supported

Supported

Generate scalar inlined parameters as #DEFINE statements

Not supported

Supported

MAT-file variable name modifier

Supported

Supported

Data exchange: C API, ASAP2, external mode

Supported

Supported

Compare Generated Code Features by STF

The code generator supports a selection of generated code features for different types of system target files. In each system target file, the value of the CodeFormat TLC variable identifies the set of features.

This table summarizes how different system target files support applications.

Application

System Target File (STF)

Fixed- or variable-step acceleration

RSIM, S-Function, Model Reference

Fixed-step real-time deployment

GRT, ERT, Simulink Real-Time, Simulink Desktop Real-Time, ...

This table summarizes the various options available for each System target file selection, with the exceptions noted.

Features Supported in Code Generated for System Target Files (STF)

 System Target Files (STF)

Feature

grt.tlc

(See note 1.)

ert.tlc

(See note 1.)

ert_shrlib.tlc

(See note 1.)

rtwsfcn.tlc

(See note 1.)

rsim.tlc

(See note 1.)

sldrt.tlc

(See note 1.)

slrt.tlc

(See note 1.)

Other

(See note 1.)

Static memory allocation

X

X

 

 

 

X

X

X

Dynamic memory allocation

X

(See notes 4, 5.)

X

(See notes 4, 5.)

 

X

X

 

X

 

Continuous time

X

X

 

X

X

X

X

 

C/C++ MEX S-functions
(noninlined)

X

X

 

X

X

X

X

 

S-function (inlined)

X

X

 

X

X

X

X

X

Minimize RAM/ROM usage

 

X

 

 

 

 

X2

X

Supports external mode

X

X

 

 

X

X

X

 

Rapid prototyping

X

 

 

 

 

X

X

X

Production code

 

X

 

 

 

 

X2

X

(See note 3.)

Batch parameter tuning and Monte Carlo methods

 

 

X

 

X

 

 

 

System-level Simulator

 

 

X

 

 

 

 

 

Executes in hard real time

X

(See note 3.)

X

(See note 3.)

 

 

 

X

X

X5

Non-real-time executable included

X

X

 

 

X

 

 

 

Multiple instances of model

X

(See notes 4, 5.)

X

(See notes 4, 5.)

 

X4

 

 

X

(See notes 4, 5.)

X

(See notes 4, 5.)

Supports variable-step solvers

 

 

 

X

X

 

 

 

Supports SIL/PIL

 

X

 

 

 

 

 

X

Notes

  1. System Target Files:

    • grt.tlc - generic real-time target

    • ert.tlc - embedded real-time target

    • ert_shrlib.tlc - embedded real-time target shared library)

    • rtwsfcn.tlc - S-Function

    • rsim.tlc - rapid simulation

    • sldrt.tlc - Simulink Desktop Real-Time

    • slrt.tlc - Simulink Real-Time

    • Other - The embedded real-time capabilities in Simulink Coder support other system target files

  2. Does not apply to GRT-based system target files. Applies to only ERT-based system target files.

  3. The default GRT and ERT rt_main files emulate execution of hard real time. When explicitly connected to a real-time clock, they execute in hard real time.

  4. You can generate code for multiple instances of a Stateflow chart or subsystem containing a chart, except when the chart contains exported graphical functions or the Stateflow model contains machine-parented events.

  5. In the Configuration Parameters dialog box, for the Code interface packaging field, select Reusable function.

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