Recommended Settings Summary for Model Configuration Parameters

R2026b

The following table summarizes the impact of each configuration parameter on debugging, traceability, efficiency, and safety considerations, and indicates the factory default configuration settings for the GRT and ERT targets, unless otherwise specified.

For parameters that are available only when an ERT target is specified, see Recommended Settings Summary for Model Configuration Parameters (Embedded Coder).

For additional details, click the links in the Configuration Parameter column.

Mapping Application Requirements to the Solver Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Start time	No impact	No impact	No impact	0.0	0.0 seconds
Stop time	No impact	No impact	No impact	A positive value	10.0 seconds
Type	Fixed-step	Fixed-step	Fixed-step	Fixed-step	Variable-step (you must change to Fixed-step for code generation)
Solver	No impact	No impact	No impact	Discrete (no continuous states)	ode3 (Bogacki-Shampine)
Periodic sample time constraint	No impact	No impact	No impact	Specified or Ensure sample time independent	Unconstrained
Sample time properties	No impact	No impact	No impact	Period, offset, and priority of each sample time in the model; faster sample times must have higher priority than slower sample times	''
Treat each discrete rate as a separate task	No impact	No impact	No impact	No impact	On
Automatically handle rate transition for data transfer	No impact	No impact (for simulation and during development) Off (for production code generation)	No impact	Off	Off

Mapping Application Requirements to the Data Import/Export Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Input	No impact	No impact	No recommendation	No recommendation	Off
Initial state	No impact	No impact	No recommendation	No recommendation	Off
Time	No impact	No impact	No recommendation	No recommendation	On
States	No impact	No impact	No recommendation	No recommendation	Off
Output	No impact	No impact	No recommendation	No recommendation	On
Final states	No impact	No impact	No recommendation	No recommendation	Off
Signal logging	No impact	No impact	No recommendation	No recommendation	On
Record logged workspace data in Simulation Data Inspector	No impact	No impact	No recommendation	No recommendation	Off
Limit data points to last	No impact	No impact	No recommendation	No recommendation	On
Decimation	No impact	No impact	No recommendation	No recommendation	1
Format	No impact	No impact	No recommendation	No recommendation	Array
Output options	No impact	No impact	No recommendation	No recommendation	Refine output
Refine factor	No impact	No impact	No recommendation	No recommendation	1
Output times	No impact	No impact	No recommendation	No recommendation	'[]'

Mapping Application Requirements to the Math and Data Types Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Default for underspecified data type	No impact	No impact	single	No impact	double
Use division for fixed-point net slope computation	No impact	No impact	On (when target hardware supports efficient division) Off (otherwise)	No impact	off
Application lifespan (days)	No impact	No impact	Finite value	inf	auto
Use floating-point multiplication to handle net slope corrections	No impact	No impact	On (when target hardware supports efficient multiplication) Off (otherwise)	No recommendation	Off

Mapping Application Requirements to the Optimization Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Default parameter behavior	Tunable during development Inlined for production code generation	Tunable	Inlined	No impact	Tunable (GRT) Inlined (ERT)
Loop unrolling threshold	No impact	No impact	>0	No impact	5
Maximum stack size (bytes)	No impact	No impact	No impact	No impact	Inherit from target
Use memcpy for vector assignment	No impact	No impact	On	No impact	On
Memcpy threshold (bytes)	No impact	No impact	Accept default or determine target-specific optimal value	No impact	64
Inline invariant signals	Off	Off	On	No impact	Off
Remove code from floating-point to integer conversions that wraps out-of-range values	Off	Off	On (execution, ROM) No impact (RAM)	No impact	Off
Use bitsets for storing state configuration	Off	Off	Off (execution, ROM) On (RAM)	No impact	Off
Use bitsets for storing Boolean data	Off	Off	Off (execution, ROM) On (RAM)	No impact	Off
Base storage type for automatically created enumerations	No recommendation	No recommendation	No recommendation	No recommendation	Native Integer
Buffer for reusable subsystems	No impact	No impact	Off (execution speed), On (ROM)	No impact	On
Reuse local block outputs	Off	Off	On	No impact	On
Remove code from floating-point to integer conversions with saturation that maps NaN to zero	Off	Off	On	No recommendation	On
Eliminate superfluous local variables (Expression folding)	Off	No impact for simulation or during development Off for production code generation	On	No impact	On
Function inlining between MathWorks functions	Readability	Readability	Speed and Always	No impact	Speed
Function inlining between user and MathWorks functions	Readability	Readability	Speed and Always	No impact	Speed
Function inlining between user functions	Readability	Readability	Speed and Always	No impact	Speed
Leverage target hardware instruction set extensions	No impact	No impact	Instruction set supported by your target hardware (execution speed)	For Intel hardware: SSE, SSE2, SSE4.1, AVX, AVX2, None For ARM Cortex-A hardware: None, Neon v7 with FMA set to Off	None
FMA	No impact	No impact	On (execution speed)	Off	Off
Enable local block outputs	Off	Off	On	No impact	On
Use memset to initialize floats and doubles to 0.0	No impact	No impact	On (execution, ROM), No impact (RAM)	No impact	On
Signal storage reuse	Off	Off	On	No impact	On
Optimize reductions	No impact	No impact	On (execution speed)	Off	Off

Mapping Application Requirements to the Diagnostics Pane: Solver Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Algebraic loop	error	No impact	No impact	error	warning
Artificial algebraic loop occurrences not eliminated	No impact	No impact	No impact	error	warning
Block priority violation	No impact	No impact	No impact	error	warning
Consecutive zero-crossings violation	No impact	No impact	No impact	warning or error	error
Unspecified inheritability of sample time	No impact	No impact	No impact	error	warning
Solver data inconsistency	warning	No impact	none	No impact	warning
Automatic solver parameter selection	No impact	No impact	No impact	error	warning

Mapping Application Requirements to the Diagnostics Pane: Sample Time Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Source block specifies -1 sample time	No impact	No impact	No impact	error	none
Multitask rate transition	No impact	No impact	No impact	error	error
Single task rate transition	No impact	No impact	No impact	none or error	none
Multitask conditionally executed subsystem	No impact	No impact	No impact	error	error
Tasks with equal priority	No impact	No impact	No impact	none or error	warning
Enforce sample times specified by Signal Specification blocks	No impact	No impact	No impact	error	warning

Mapping Application Requirements to the Diagnostics Pane: Data Validity Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Signal resolution	Explicit only or None	Explicit only or None	Explicit only or None	Explicit only	Explicit only
Division by singular matrix	No impact	No impact	No impact	error	none
Underspecified data types	No impact	No impact	No impact	error	none
Simulation range checking	warning or error	warning or error	none	error	none
Wrap on overflow	No impact	No impact	No impact	error	warning
Saturate on overflow	No impact	No impact	No impact	error	warning
Inf or NaN block output	No impact	No impact	No impact	error	none
"rt" prefix for identifiers	No impact	No impact	No impact	error	error
Detect downcast	No impact	No impact	No impact	error	error
Detect overflow	No impact	No impact	No impact	error	error
Detect underflow	No impact	No impact	No impact	error	none
Detect precision loss	No impact	No impact	No impact	error	warning
Detect loss of tunability	No impact	No impact	No impact	error	warning for GRT-based targets error for ERT-based targets
Detect read before write	No impact	No impact	No impact	error	Enable all as warnings
Detect write after read	No impact	No impact	No impact	error	Enable all as warning
Detect write after write	No impact	No impact	No impact	error	Enable all as errors
Multitask data store	No impact	No impact	No impact	error	warning
Duplicate data store names	warning	No impact	none	No impact	none
Check undefined subsystem initial output	No impact	No impact	No impact	On	On

Mapping Application Requirements to the Diagnostics Pane: Type Conversion Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Unnecessary type conversions	No impact	No impact	No impact	warning	none
Vector/matrix block input conversion	No impact	No impact	No impact	error	none
32-bit integer to single precision float conversion	No impact	No impact	No impact	warning	warning

Mapping Application Requirements to the Diagnostics Pane: Connectivity Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Signal label mismatch	No impact	No impact	No impact	error	none
Unconnected block input ports	No impact	No impact	No impact	error	none
Unconnected block output ports	No impact	No impact	No impact	error	none
Unconnected line	No impact	No impact	No impact	error	none
Unspecified bus object at root Outport block	No impact	No impact	No impact	error	warning
Element name mismatch	No impact	No impact	No impact	error	warning
Bus signal treated as vector	No impact	No impact	No impact	error	none
Context-dependent inputs	No impact	No impact	No impact	error	error

Mapping Application Requirements to the Diagnostics Pane: Compatibility Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
S-function upgrades needed	No impact	No impact	No impact	error	none

Mapping Application Requirements to the Diagnostics Pane: Model Referencing Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Model block version mismatch	No impact	No impact	No impact	No recommendation	none
Port and parameter mismatch	No impact	No impact	No impact	error	none
Unsupported data logging	No impact	No impact	No impact	error	warning

Mapping Application Requirements to the Diagnostics Pane: Saving Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Block diagram contains disabled library links	No impact	No impact	No impact	No impact	warning
Block diagram contains parameterized library links	No impact	No impact	No impact	No impact	none

Mapping Application Requirements to the Diagnostics Pane: Stateflow Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Unused data, events, messages, and functions	warning	No impact	No impact (for simulation and during development) none (for production code generation)	warning	warning
Unexpected backtracking	warning	No impact	No impact	error	warning
Invalid input data access in chart initialization	warning	No impact	No impact	error	warning
No unconditional default transitions	warning	No impact	No impact (for simulation and during development) none (for production code generation)	error	warning
Transition outside natural parent	warning	No impact	No impact (for simulation and during development) none (for production code generation)	error	warning

Mapping Application Requirements to the Hardware Implementation Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Device vendor	No impact	No impact	No impact	Select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	None if specified system target file is ert.tlc, realtime.tlc, or autosar.tlc. Otherwise, Determine by Code Generation system target file
Device vendor	No impact	No impact	No impact	Select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	Intel
Device type	No impact	No impact	No impact	Select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	x86–64 (Windows64)
Number of bits: char	No impact	No impact	Target specific	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	char 8, short 16, int 32, long 32, long long 64, float 32, double 64, native 32, pointer 32
Largest atomic size: integer	No impact	No impact	Target specific	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	integer Char, floating-point Float
Byte ordering	No impact	No impact	No impact	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	Little Endian
Signed integer division rounds to	No impact for simulation and during development Undefined for production code generation	No impact for simulation and during development Zero or Floor for production code generation	No impact for simulation and during development Zero for production code generation	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	Zero
Shift right on a signed integer as arithmetic shift	No impact	No impact	On	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	On
Support long long	No impact	No impact	On (execution, ROM)	No recommendation for simulation without code generation. For simulation with code generation, select your Device vendor and Device type if they are available in the drop-down list.  If your Device vendor and Device type are not available, set device-specific values by using Custom Processor.	Off

Mapping Application Requirements to the Model Referencing Pane

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Rebuild	No impact	No impact	No impact	If changes detected or Never If you use the Never setting, then set the Never rebuild diagnostic parameter to Error if rebuild required	If changes in known dependencies detected (since R2026a) Before R2026a: If changes detected
Never rebuild diagnostic	No impact	No impact	No impact	Error if rebuild required	Error if rebuild required
Enable parallel model reference builds	No impact	No impact	No impact	No impact	Off
MATLAB worker initialization for builds	No impact	No impact	No impact	No impact	None
Total number of instances allowed per top model	No impact	No impact	No impact	No recommendation	Multiple
Pass fixed-size scalar root inputs by value for code generation	No impact	No impact	No impact	No recommendation	Off
Minimize artificial algebraic loop occurrences	No impact	No impact	No impact	No recommendation	Off
Propagate sizes of variable-size signals	No impact	No impact	No impact	No recommendation	Infer from blocks in model
Model dependencies	No impact	No impact	No impact	No recommendation	''

Mapping Application Requirements to the Simulation Target Pane: General Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Enable memory integrity checks	On	No impact	No recommendation	On	On
Echo expressions without semicolons	On	No impact	Off	No impact	On
Break on Ctrl+C	On	No recommendation	No recommendation	No recommendation	On

Mapping Application Requirements to the Simulation Target Pane: Symbols Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Reserved names	No impact	No impact	No impact	No recommendation	{}

Mapping Application Requirements to the Simulation Target Pane: Custom Code Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Parse custom code symbols	On	No impact	No impact	On	On
Source file	No recommendation	No recommendation	No recommendation	No recommendation	''
Header file	No recommendation	No recommendation	No recommendation	No recommendation	''
Initialize function	No recommendation	No recommendation	No recommendation	No recommendation	''
Terminate function	No recommendation	No recommendation	No recommendation	No recommendation	''
Include directories	No impact	No impact	No impact	No recommendation	''
Source files	No impact	No impact	No impact	No recommendation	''
Libraries	No impact	No impact	No impact	No recommendation	''
Defines	No impact	No impact	No impact	No recommendation	''

Mapping Application Requirements to the Code Generation Pane: General Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
System target file	No impact	No impact	No impact	No impact (GRT) ERT based (ERT)	grt.tlc
Language	No impact	No impact	No impact	No impact	C
Language standard	No impact	No impact	Valid library	No impact	C99 (ISO) for C; C++11 (ISO) for C++
Compiler optimization level	Optimizations off (faster builds)	Optimizations off (faster builds)	Optimizations on (faster runs) (execution) No impact (ROM, RAM)	No impact	Optimizations off (faster builds)
Custom compiler optimization flags	Optimizations off (faster builds)	Optimizations off (faster builds)	Optimizations on (faster runs)	No impact	Optimizations off (faster builds)
Generate makefile	No impact	No impact	No impact	No impact	On
Make command	No impact	No impact	No impact	No recommendation	make_rtw
Template makefile	No impact	No impact	No impact	No impact	grt_default_tmf
Select objective	Debugging	Not applicable for GRT-based targets	Execution efficiency	No recommendation	Unspecified
Check model before generating code	On (proceed with warnings) or On (stop for warnings)	On (proceed with warnings) or On (stop for warnings)	On (proceed with warnings) or On (stop for warnings)	On (proceed with warnings) or On (stop for warnings)	Off
Generate code only	Off	No impact	No impact	No impact	Off
Verbose build	On	No impact	No impact	No recommendation	On
Retain .rtw file	On	No impact	No impact	No impact	Off
Profile TLC	On	No impact	No impact	No impact	Off
Start TLC debugger when generating code	On	No impact	No impact	No impact	Off
Start TLC coverage when generating code	On	No impact	No impact	No impact	Off
Enable TLC assertion	On	No impact	No impact	No recommendation	Off
Build configuration	Debug	No impact	Faster Runs	No impact	Release or Faster Builds
Built-in FFTW library callback	No impact	No impact	No impact	No impact	Off
Custom BLAS library callback	No impact	No impact	No impact	No impact	''
Custom FFT library callback	No impact	No impact	No impact	No impact	''
Custom LAPACK library callback	No impact	No impact	No impact	No impact	''
Toolchain details	No recommendation	No recommendation	No recommendation	No recommendation	''
Large constant generation in MATLAB functions	No impact	No impact	Write only deep learning constants to data files	No impact	KeepInSourceFiles
Large constant threshold in MATLAB functions (bytes)	No impact	No impact	Depends on your application	No impact	131072
Package code and artifacts	No impact	No impact	No impact	No impact	Off
Zip file name	No impact	No impact	No impact	No impact	Off
Show Custom Hardware App in Simulink Toolstrip	On	No impact	No impact	No recommendation	Off
Show Embedded Hardware App in Simulink Toolstrip	On	No impact	No impact	No recommendation	Off
Toolchain	No impact	No impact	No impact	No impact	Automatically locate an installed toolchain

Mapping Application Requirements to the Code Generation Pane: Report Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Create code generation report	On	On	No impact	No recommendation	Off
Open report automatically	On	On	No impact	No impact	Off

Mapping Application Requirements to the Code Generation Pane: Comments Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Include comments	On	On	No impact	No recommendation	On
Simulink block comments	On	On	No impact	No recommendation	On
Stateflow object comments	On	On	No impact	No recommendation	Off
Show eliminated blocks	On	On	No impact	No recommendation	On
Verbose comments for 'Model default' storage class	On	On	No impact	No recommendation	On
Operator annotations (Embedded Coder)	No impact	On	No impact	No recommendation	On
MATLAB source code as comments	On	On	No impact	No recommendation	Off

Mapping Application Requirements to the Code Generation Pane: Identifiers Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Maximum identifier length	Valid value	>30	No impact	>30	31
Use the same reserved names as Simulation Target	No impact	No impact	No impact	No impact	Off
Reserved names	No impact	No impact	No impact	No impact	{}
Duplicate enumeration member names	No impact	No impact	No impact	No impact	error
Header guard prefix	No impact	No impact	No impact	No impact	''

Mapping Application Requirements to the Code Generation Pane: Custom Code Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Use the same custom code settings as Simulation Target	No impact	No impact	No impact	No impact	Off
Additional code	No impact	No impact	No impact	No impact	''
Include headers	No impact	No impact	No impact	No impact	''
Initialize code	No impact	No impact	No impact	No impact	''
Terminate code	No impact	No impact	No impact	No impact	''
Include directories	No impact	No impact	No impact	No impact	''
Source files	No impact	No impact	No impact	No impact	''
Libraries	No impact	No impact	No impact	No impact	''
Defines	No impact	No impact	No impact	No impact	''

Mapping Application Requirements to the Code Generation Pane: Interface Tab

Configuration Parameter	Settings for Building Code				Factory Default
	Debugging	Traceability	Efficiency	Safety precaution
Code replacement library	No impact	No impact	Valid library	No impact	None
Shared code placement	Shared location (GRT) No impact (ERT)	Shared location (GRT) No impact (ERT)	No impact (execution, RAM) Shared location (ROM)	No impact	Auto
Support: non-finite numbers	No impact	No impact	Off (Execution, ROM) No impact (RAM)	No recommendation	On
Code interface packaging	No impact	No impact	Reusable function or C++ class	No impact	Nonreusable function if Language is set to C; C++ class if Language is set to C++
Multi-instance code error diagnostic	Warning or Error	No impact	None	No impact	Error
Single output/update function	On	On	On	No recommendation	On
MAT-file logging	On	No impact	Off	Off	On (GRT) Off (ERT)
Suppress generation of fixed-point word size checks	No impact	No impact	No impact	Off On if you check code generator assumptions. See Check Code Generation Assumptions (Embedded Coder) and Verification of Code Generation Assumptions (Embedded Coder).	Off
MAT-file variable name modifier (Embedded Coder)	No impact	No impact	No impact	No impact	rt_
Generate C API for: signals	No impact	No impact	No impact	No impact (development) Off (production)	Off
Generate C API for: parameters	No impact	No impact	No impact	No impact (development) Off (production)	Off
Generate C API for: states	No impact	No impact	No impact	No impact (development) Off (production)	Off
Generate C API for: root-level I/O	No impact	No impact	No impact	No impact (development) Off (production)	Off
External mode	No impact	No impact	No impact	No impact (development) Off (production)	Off
Transport layer	No impact	No impact	No impact	No impact	tcpip
MEX-file arguments	No impact	No impact	No impact	No impact	''
Static memory allocation	No impact	No impact	No impact	No impact	Off
Array layout	No impact	No impact	No impact	No impact	Column-major
Buffer size of dynamically-sized string (bytes)	No impact	No impact	No impact	No impact	256
Automatically allocate static memory	No impact	No impact	No impact	No impact	On
Maximum duration	No impact	No impact	No impact	No impact	10
Static memory buffer size	No impact	No impact	No impact	No impact	1000000
Generate full file banner	No impact	No impact	No impact	No impact	On
Classic call interface	No impact	Off	Off (execution, ROM), No impact (RAM)	No recommendation	Off (except On for GRT models created before R2012a)
Target derived from slrealtime	On	On	On	On	On
Log signals to MDF file	On	No impact	Off	No recommendation	Off
LUT object struct order for even spacing specification	No impact	No impact	No impact	No impact	Size,Breakpoints,Table
LUT object struct order for explicit value specification	No impact	No impact	No impact	No impact	Size,Breakpoints,Table
Maximum word length	No impact	No impact	No impact	No recommendation	2048 for GRT targets, 256 for ERT targets
Code interface packaging (subcomponent)	No impact	No impact	Reusable function or C++ class	No impact	Reusable function if TargetLang is set to C; C++ class if TargetLang is set to C++
External functions compatibility for row-major code generation	warning	No impact	No impact	error	error