Main Content


Register fixed-point data type with binary-point-only scaling and return its data type ID


extern DTypeId ssRegisterDataTypeFxpBinaryPoint
                                 (SimStruct *S,
                                  int isSigned,
                                  int wordLength,
                                  int fractionLength,
                                  int obeyDataTypeOverride)



SimStruct representing an S-function block.


TRUE if the data type is signed.

FALSE if the data type is unsigned.


Total number of bits in the data type, including any sign bit.


Number of bits in the data type to the right of the binary point.


TRUE indicates that the Data Type Override setting for the subsystem is to be obeyed. Depending on the value of Data Type Override, the resulting data type could be Double, Single, Scaled double, or the fixed-point data type specified by the other arguments of the function.

FALSE indicates that the Data Type Override setting is to be ignored.


This function fully registers a fixed-point data type with the Simulink® software and returns a data type ID. Note that unlike the standard Simulink function ssRegisterDataType, you do not need to take any additional registration steps. The data type ID can be used to specify the data types of input and output ports, run-time parameters, and DWork states. It can also be used with all the standard data type access methods in simstruc.h, such as ssGetDataTypeSize.

Use this function if you want to register a fixed-point data type with binary-point-only scaling. Alternatively, you can use one of the other fixed-point registration functions:

If the registered data type is not one of the Simulink built-in data types, a Fixed-Point Designer™ software license is checked out. To prevent a Fixed-Point Designer software license from being checked out when you simply open or view a model, protect registration calls with



Because of the nature of the assignment of data type IDs, you should always use API functions to extract information from a data type ID about a data type in your S-function. For more information, refer to Data Type IDs.


To use this function, you must include fixedpoint.h and fixedpoint.c. For more information, see Structure of the S-Function.



TLC Functions

None. Data types should be registered in the Simulink software. Registration of data types is not supported in TLC.

Version History

Introduced before R2006a