Code You Can Replace From Simulink Models

Code that the code generator replaces depends on the code replacement library (CRL) that you use. By default, the code generator does not apply a code replacement library. Your choice of libraries is dependent on product licensing and whether you have access to custom libraries.

For information on how to explore functions and operators that a code replacement library supports, see Choose a Code Replacement Library.

Math Functions – Simulink Support

When generating C/C++ code from a Simulink^® model, depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following math functions with application-specific implementations. To replace math functions that you use inside MATLAB function blocks, the functions must also meet the requirements in Code You Can Replace from MATLAB Code.

Function	Data Type Support	Scalar, Vector, Matrix Support	Real, Complex Support
abs1	Integer Floating point Fixed point	Scalar Vector Matrix	Real
acos	Floating point	Scalar	Real Complex input/complex output Real input/complex output
acosd2	Floating point	Scalar Vector Matrix	Real Complex
acosh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
acot2	Floating point	Scalar Vector Matrix	Real Complex
acotd2	Floating point	Scalar Vector Matrix	Real Complex
acoth2	Floating point	Scalar Vector Matrix	Real Complex
acsc2	Floating point	Scalar Vector Matrix	Real Complex
acscd2	Floating point	Scalar Vector Matrix	Real Complex
acsch2	Floating point	Scalar Vector Matrix	Real Complex
asec2	Floating point	Scalar Vector Matrix	Real Complex
asecd2	Floating point	Scalar Vector Matrix	Real Complex
asech2	Floating point	Scalar Vector Matrix	Real Complex
asin	Floating point	Scalar	Real Complex input/complex output Real input/complex output
asind2	Floating point	Scalar Vector Matrix	Real Complex
asinh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
atan	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
atan23	Floating point	Scalar Vector Matrix	Real
atan2d2	Floating point	Scalar Vector Matrix	Real
atand2	Floating point	Scalar Vector Matrix	Real Complex
atanh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
ceil	Floating-point Scalar	Floating-point Scalar	Floating-point Scalar
circularIndex — Delay block with Use circular buffer for state selected.	Integer	Scalar	Real
cos3	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
cosd2	Floating point	Scalar Vector Matrix	Real Complex
cosh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
cot2	Floating point	Scalar Vector Matrix	Real Complex
cotd2	Floating point	Scalar Vector Matrix	Real Complex
coth2	Floating point	Scalar Vector Matrix	Real Complex
csc2	Floating point	Scalar Vector Matrix	Real Complex
cscd2	Floating point	Scalar Vector Matrix	Real Complex
csch2	Floating point	Scalar Vector Matrix	Real Complex
exactrSqrt — Sqrt block with: Function set to rSqrt Method set to Exact	Integer Floating point	Scalar	Real
exp	Floating point	Scalar Vector Matrix	Real
fix	Floating point	Scalar	Real
floor	Floating-point Scalar	Floating-point Scalar	Floating-point Scalar
fmod4	Floating point	Scalar	Real
frexp	Floating point	Scalar	Real
hypot	Floating point	Scalar Vector Matrix	Real
ldexp	Floating point	Scalar	Real
ln	Floating point	Scalar	Real
log	Floating point	Scalar Vector Matrix	Real
log10	Floating point	Scalar Vector Matrix	Real
log22	Floating point	Scalar Vector Matrix	Real Complex
max	Integer Floating point Fixed point	Scalar	Real
min	Integer Floating point Fixed point	Scalar	Real
mod	Integer Floating point	Scalar Vector Matrix	Real
pow	Floating point	Scalar Vector Matrix	Real
rem	Floating point	Scalar Vector Matrix	Real
round	Floating point	Scalar	Real
rSqrt	Integer Floating point	Scalar Vector Matrix	Real
saturate	Integer Floating point Fixed point	Scalar Vector Matrix	Real
sec2	Floating point	Scalar Vector Matrix	Real Complex
secd2	Floating point	Scalar Vector Matrix	Real Complex
sech2	Floating point	Scalar Vector Matrix	Real Complex
sign	Integer Floating point Fixed point	Scalar Vector Matrix	Real
signPow — Math Function block with: Function set to pow Signed power enabled	Floating point	Scalar Vector Matrix	Real
sin3	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
sincos3	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
sind2	Floating point	Scalar Vector Matrix	Real Complex
sinh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
sqrt	Integer Floating point Fixed point	Scalar Vector Matrix	Real
tan	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
tand2	Floating point	Scalar Vector Matrix	Real Complex
tanh	Floating point	Scalar Vector Matrix	Real Complex input/complex output Real input/complex output
1 Wrap on integer overflow only. Clear block parameter Saturate on integer overflow. 2 Only when used with the MATLAB Function block. 3 Supports the CORDIC approximation method and the Lookup approximation method. 4 Stateflow® support only.

Math Functions – Stateflow Support

When generating C/C++ code from Stateflow charts, depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following math functions with application-specific implementations.

Function	Data Type Support	Scalar, Vector, Matrix Support	Real, Complex Support
abs1	Integer Floating point	Scalar	Real
acos2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
acosd3	Floating point	Scalar Vector Matrix	Real Complex
acot3	Floating point	Scalar Vector Matrix	Real Complex
acotd3	Floating point	Scalar Vector Matrix	Real Complex
acoth3,5	Floating point	Scalar Vector Matrix	Real Complex
acsc3	Floating point	Scalar Vector Matrix	Real Complex
acscd3	Floating point	Scalar Vector Matrix	Real Complex
acsch3	Floating point	Scalar Vector Matrix	Real Complex
asec3	Floating point	Scalar Vector Matrix	Real Complex
asecd3	Floating point	Scalar Vector Matrix	Real Complex
asech3	Floating point	Scalar Vector Matrix	Real Complex
asin2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
asind3	Floating point	Scalar Vector Matrix	Real Complex
atan2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
atan22	Floating point	Scalar Vector Matrix	Real
atan2d3	Floating point	Scalar Vector Matrix	Real
atand3	Floating point	Scalar Vector Matrix	Real Complex
ceil	Floating-point Scalar	Floating-point Scalar	Floating-point Scalar
cos3	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
cosd3	Floating point	Scalar Vector Matrix	Real Complex
cosh2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
cot3	Floating point	Scalar Vector Matrix	Real Complex
cotd3	Floating point	Scalar Vector Matrix	Real Complex
coth3	Floating point	Scalar Vector Matrix	Real Complex
csc3	Floating point	Scalar Vector Matrix	Real Complex
cscd3	Floating point	Scalar Vector Matrix	Real Complex
csch3	Floating point	Scalar Vector Matrix	Real Complex
exp	Floating point	Scalar	Real
floor	Floating-point Scalar	Floating-point Scalar	Floating-point Scalar
fmod	Floating point	Scalar	Real
hypot3	Floating point	Scalar Vector Matrix	Real
ldexp	Floating point	Scalar	Real
log2	Floating point	Scalar Vector Matrix	Real Complex
log102	Floating point	Scalar Vector Matrix	Real Complex
log23	Floating point	Scalar Vector Matrix	Real Complex
max	Integer Floating point	Scalar	Real
min	Integer Floating point	Scalar	Real
pow	Floating point	Scalar	Real
sec3	Floating point	Scalar Vector Matrix	Real Complex
secd3	Floating point	Scalar Vector Matrix	Real Complex
sech3	Floating point	Scalar Vector Matrix	Real Complex
sin2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
sind3	Floating point	Scalar Vector Matrix	Real Complex
sinh2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
sqrt	Floating point	Scalar	Real
tan2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
tand3	Floating point	Scalar Vector Matrix	Real Complex
tanh2	Floating point	Scalar Vector Matrix	Real Complex Complex input/complex output Real input/complex output
1 Wrap on integer overflow only. 2 For models involving vectors or matrices, the code generator replaces only functions coded in the MATLAB® action language. 3 The code generator replaces only functions coded in the MATLAB action language.

Memory Functions

Depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following memory functions with application-specific implementations.

Function	Data Type Support	Scalar, Vector, Matrix Support	Real, Complex Support
memcmp	Void pointer (void*)	Scalar Vector Matrix	Real Complex
memcpy	Void pointer (void*)	Scalar Vector Matrix	Real Complex
memset	Void pointer (void*)	Scalar Vector Matrix	Real Complex
memset2zero	Void pointer (void*)	Scalar Vector Matrix	Real Complex

Some target processors provide optimized functions to set memory to zero. Use the code replacement library programming interface to replace the memset2zero function with more efficient target-specific functions.

Nonfinite Functions

Depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following nonfinite functions with application-specific implementations.

Function	Data Type Support	Scalar, Vector, Matrix Support	Real, Complex Support
getInf	Floating point	Scalar	Real
getMinusInf	Floating point	Scalar	Real
getNaN	Floating point	Scalar	Real
rtIsInf	Floating point	Scalar	Real Complex
rtIsNaN	Floating point	Scalar	Real Complex

Mutex and Semaphore Functions

Mutex and semaphore functions control access to resources shared by multiple processes in multicore target environments. MathWorks^® provides code replacement libraries that support mutex and semaphore replacement for Rate Transition and Task Transition blocks on Windows^®, Linux^®, Mac, and VxWorks^® platforms.

Generated mutex and semaphore code typically consists of:

• In model initialization code, an initialization function call to create a mutex or semaphore to control entry to a critical section of code.

• In model step code:

  • Before code for a data transfer between tasks enters the critical section, mutex lock or semaphore wait function calls to reserve a critical section of code.

  • After code for a data transfer between tasks finishes executing the critical section, mutex unlock or semaphore post function calls to release the critical section of code.

• In model termination code, an optional destroy function call to explicitly delete the mutex or semaphore.

Depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following mutex and semaphore functions with application-specific implementations.

Function	Key
Mutex Destroy	RTW_MUTEX_DESTROY
Mutex Init	RTW_MUTEX_INIT
Mutex Lock	RTW_MUTEX_LOCK
Mutex Unlock	RTW_MUTEX_UNLOCK
Semaphore Destroy	RTW_SEM_DESTROY
Semaphore Init	RTW_SEM_INIT
Semaphore Post	RTW_SEM_POST
Semaphore Wait	RTW_SEM_WAIT

Operators

When generating C/C++ code from a Simulink model, depending on code replacement libraries available in your development environment, you can configure the code generator to replace instances of the following operators with application-specific implementations.

Mixed data type support indicates that you can specify different data types for different inputs.

Operator	Key	Data Type Support	Scalar, Vector, Matrix Support	Real, Complex Support
Addition (+)1	RTW_OP_ADD	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Subtraction (-)1	RTW_OP_MINUS	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Multiplication (*)2	RTW_OP_MUL	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Division (/)	RTW_OP_DIV	Integer Floating point Fixed-point Mixed	Scalar	Real Complex
Data type conversion (cast)	RTW_OP_CAST	Integer Floating point3 Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Shift left (<<)	RTW_OP_SL	Integer Fixed-point Mixed	Scalar Vector Matrix4	Real
Shift right arithmetic (>>)5	RTW_OP_SRA	Integer Fixed-point Mixed	Scalar Vector Matrix4	Real
Shift right logical (>>)	RTW_OP_SRL	Integer Fixed-point Mixed	Scalar Vector Matrix4	Real
Element-wise matrix multiplication (.*)6	RTW_OP_ELEM_MUL	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Matrix right division (/)	RTW_OP_RDIV	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Matrix left division (\)	RTW_OP_LDIV	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Matrix inversion (inv)	RTW_OP_INV	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Complex conjugation	RTW_OP_CONJUGATE	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Transposition (.')	RTW_OP_TRANS	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Hermitian (complex conjugate) transposition (')	RTW_OP_HERMITIAN	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Multiplication with transposition2	RTW_OP_TRMUL	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Multiplication with Hermitian transposition2	RTW_OP_HMMUL	Integer Floating point Fixed-point Mixed	Vector Matrix	Real Complex
Multiplication followed by shift right arithmetic (u1*u2>>u3)7	RTW_OP_MUL_SRA	Integer Fixed-point	Scalar	Real
Multiplication followed by division (u1*u2/u3)8	RTW_OP_MULDIV	Integer Fixed-point	Scalar	Real
Greater than (>)	RTW_OP_GREATER_ THAN	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Greater than or equal (>=)	RTW_OP_GREATER_ THAN_OR_EQUAL	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Less than (<)	RTW_OP_LESS_THAN	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Less than or equal (<=)	RTW_OP_LESS_THAN_ OR_EQUAL	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Equal (==)	RTW_OP_EQUAL	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
Not equal (!=)	RTW_OP_NOT_EQUAL	Integer Floating point Fixed-point Mixed	Scalar Vector Matrix	Real Complex
1 See Replace Addition and Subtraction Operator Code for details to consider when defining mappings for addition and subtraction code replacements. 2 Can map to Basic Linear Algebra Subroutine (BLAS) multiplication functions. 3 Scaled floating point is not supported. 4 Shift operator replacement with matrix data is supported for shift values that you specify with an input port. Replacement is not supported for shift values that you specify in a block parameter dialog. 5 The code generator converts some arithmetic shift rights to logical shift rights. To avoid unexpected results, when creating a code replacement library that includes a table entry for an arithmetic shift right implementation, also include an entry for a logical shift right implementation. 6 Use the multiplication (*) operator (RTW_OP_MUL) for scalar multiplication. 7 Requires scalar, real, or fixed-point data types with zero bias; output type of the multiplication operation to accommodate all possible output values; shift operand is an unsigned integer; and net slope is equal to 1 (U1_slope * U2_slope == Mul_output_slope and Mul_output_slope == output_slope_of_shift_operation). 8 Requires scalar, real, or fixed-point data types with zero bias; output type of the multiplication operation to accommodate all possible output values; and net slope is equal to 1 (U1_slope * U2_slope == Mul_output_slope == U3_slope * Div_output_slope).

Blocks You Can Replace

This table shows the blocks you can replace, the key for each block, block parameter settings that you can specify, and valid block parameter arguments for each block. The table also indicates which block parameter settings and block parameter arguments you are required to set in a block replacement entry for each block. For fixed-point implementations for supported blocks, you must also specify the required data type parameters.

Block	Key	Block Parameters	Block Parameter Arguments	Data Type Block Parameters for Fixed-Point Implementations
Discrete FIR Filter	DiscreteFir	Required parameters: Coefficient source (CoefSource) Filter structure (FilterStructure) Input processing (InputProcessing)	Coefficients (Coefficients) Initial states (InitialStates)	Required parameters: Tap sum (TapSumDataTypeStr) Coefficients (CoefDataTypeStr) Product output (ProductDataTypeStr) Accumulator (AccumDataTypeStr) State (StateDataTypeStr) Output (OutDataTypeStr) Lock data type settings against changes by the fixed-point tools (LockScale) Integer rounding mode (RndMeth) Saturate on integer overflow (SaturateOnIntegerOverflow)
		Optional parameters: Coefficients (Coefficients) Initial states (InitialStates) Show enable port (ShowEnablePort) External reset (ExternalReset) Sample time (SampleTime)		Not supported — do not specify these parameters: Coefficients minimum (CoeffMin) Coefficients maximum (CoeffMax) Output minimum (OutMin) Output maximum (OutMax)
Biquad Filter (DSP System Toolbox)	Biquad Filter	Required parameters: Coefficient source (FilterSource) Filter structure (IIRFiltStruct) Input processing (InputProcessing)	SOS Matrix (Mx6) (BiQuadCoeffs) Initial conditions (IC) Initial conditions on zeros side (ICnum) Initial conditions on poles side (ICden) Scale values (ScaleValue)	Required parameters: Rounding mode (RoundingMode) Saturate on integer overflow (OverflowMode) Coefficients (firstCoeffMode) Product output (prodOutputMode) Accumulator (accumMode) States (memoryMode) Output (outputMode) Section input (stageInputMode) Section output (stageOutputMode) Multiplicand (multiplicandMode) Lock data type settings against changes by the fixed-point tools (LockScale)
		Optional parameters: SOS Matrix (Mx6) (BiQuadCoeffs) Scale values (ScaleValues) Initial conditions (IC) Initial conditions on zeros side (ICnum) Initial conditions on poles side (ICden) Scale values mode (ScaleValueMode) Action when the a0 values of the SOS matrix are not one (a0Flag) Optimize unity scale values (OptimizeUnityScaleValues)
FFT (DSP System Toolbox)	FFT	Required parameters: FFT implementation (FFTImplementation) Output in bit-reversed order (BitRevOrder) Divide output by FFT length (Normalize) Inherit FFT length from input dimensions (InheritFFTLength) FFT length (FFTLength) — Required if InheritFFTLength is off Wrap input data when FFT length is shorter than input length (WrapInput) — Required if InheritFFTLength is off	None	Fixed-point implementations are not supported.
IFFT (DSP System Toolbox)	IFFT	Required parameters: FFT implementation (FFTImplementation) Input is in bit-reversed order (BitRevOrder) Input is conjugate symmetric (cs_in) Divide output by FFT length (Normalize) Inherit FFT length from input dimensions (InheritFFTLength) FFT length (FFTLength) — Required if InheritFFTLength is off Wrap input data when FFT length is shorter than input length (WrapInput) — Required if InheritFFTLength is off	None	Fixed-point implementations are not supported.
FIR Decimation (DSP System Toolbox)	FIR Decimation	Required parameters: Coefficient source (FilterSource) — Must be set to dialog parameters, input port, or auto Decimation factor (D) FIR filter coefficients (h) — Required if FilterSource is dialog parameters Filter structure (FiltStruct) Input processing (InputProcessing) Rate options (framing) Output buffer initial conditions (OutputBufInitCond) — Required if framing is allow multirate processing Allow arbitrary frame length for fixed-size input signals (AllowArbitraryInputLength) — Required if framing is enforce single-rate processing	Decimation factor (D) FIR filter coefficients (h) — Required if FilterSource is dialog parameters	Fixed-point implementations are not supported.
FIR Interpolation (DSP System Toolbox)	FIR Interpolation	Required parameters: Coefficient source (FilterSource) — Must be set to dialog parameters, input port, or auto Interpolation factor (L) FIR filter coefficients (h) — Required if FilterSource is dialog parameters Input processing (InputProcessing) Rate options (framing) Output buffer initial conditions (OutputBufInitCond) — Required if framing is allow multirate processing	Interpolation factor (L) FIR filter coefficients (h) — Required if FilterSource is dialog parameters	Fixed-point implementations are not supported.

Related Topics

• Lookup Table Function Code Replacement
• Develop a Code Replacement Library
• Quick Start Code Replacement Library Development - Simulink
• What Is Code Replacement?
• Block Replacement for Code Optimization