MATLAB: I cannot use 64 Bit datatype in Stateflow with MATLAB Action Language in R2020a

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Why I cannot use 64 Bit datatype in Stateflow with MATLAB Action Language in R2020a?

I have a Simulink Parameter with int64 datatype and now in the Diagnostic Viewer I can see the following error:

'paramChartInt64' has a value of an unsupported type.'

In R2019a and R2019b there was no error.

I use the following code to specify the parameter:

paramChartInt64 = Simulink.Parameter;
paramChartInt64.DataType = 'int64';
paramChartInt64.Value =1;

Best Answer

In R2019a and R2019b we unintentionally allowed to use 'int64' datatype in Stateflow charts. This was fixed in R2020a and now it correctly shows an error, because it is not supported.

Our development team currently plans to include this functionality in a future release.

In the meantime you can use the following workaround:

paramChartInt64 = Simulink.Parameter;
paramChartInt64.Value = fi(-1, 1, 64, 0);

Our development team also plans to enhance the documentation about the support of 64 Bit datatypes using MATLAB Action Language in a future release.

Related Solutions

MATLAB: Can’t I use variables of type int64/uint64 as block parameter in Simulink

While int64 and uint64 are supported as built-in Simulink data types since R2019a, int64/uint64 variables as block parameters are not yet supported.

The restriction is specifically with the 'Value' parameter of Constant, or similar edit-boxed blocks (e.g. Gain blocks, Bias blocks, etc.). int64/uint64 are supported for simulation, but values cannot be cast to it.

In R2019a and later, as long as the "Output data type" is set to the correct data type, the type during simulation will be int64/uint64:

>> set_param(gcb,'Value','1')
>> set_param(gcb,'OutDataTypeStr','int64') % only available in 19a and later

To create a value with the desired data type, you can also use a Simulink.Parameter and set the data type information using the 'DataType' field. This will make sure that the value in Simulink is a 64-bit integer without needing to specify it in the 'Value' field. For example:

>> x = Simulink.Parameter(1000);
>> x.DataType = 'int64';

Unfortunately, the 'Value' of the Simulink.Parameter cannot be a 64-bit integer, but Simulink will treat operations as 64-bit since the DataType is specified as such.

An enhancement request has been submitted to development to improve the error message, and add support for int64/uint64 variables as block parameters.

MATLAB: How to use SS_UINT64 and SS_INT64 port data types in the S Function

The 'ssSetInputPortDataType' command accepts the following Built In Data Type Ids:

SS_DOUBLE /* real_T */
SS_SINGLE /* real32_T */
SS_INT8 /* int8_T */
SS_UINT8 /* uint8_T */
SS_INT16 /* int16_T */
SS_UINT16 /* uint16_T */
SS_INT32 /* int32_T */
SS_UINT32 /* uint32_T */
SS_BOOLEAN /* boolean_T */

In order to accept data of type uint64_T and int64_T the 'ssRegisterDataTypeFxpBinaryPoint' command can be used to define a custom 'DTypeID' object. The following example would produce a 'DTypeID' object corresponding to uint64_T:

DTypeId DataType_SS_UINT64 = ssRegisterDataTypeFxpBinaryPoint(
            S,
            0,  // unsigned
            64, // 64 bit
            0,  // 0 fraction length
            1 );

'DataType_SS_UINT64' can then be passed as an argument to the 'ssSetInputPortDataType' and 'ssSetOutputPortDataType' functions. The corresponding S-Function Block will then be able to accept data of type 'ufix64'.

Additional information on the 'ssRegisterDataTypeFxpBinaryPoint' command can be found here:

https://www.mathworks.com/help/releases/R2019a/fixedpoint/ug/ssregisterdatatypefxpbinarypoint.html

Note that in order to use the 'ssRegisterDataTypeFxpBinaryPoint' you must include 'fixedpoint.h' and 'fixedpoint.c' in your S Function. Additionally, for fixed-point C S-functions, pass an extra argument '-lfixedpoint' in the mex command as shown below and in the following link:

>> mex('sfun_user_fxp_asr.c','-lfixedpoint')

https://www.mathworks.com/help/releases/R2019a/fixedpoint/ug/creating-mex-files.html

Best Answer

Related Solutions

MATLAB: Can’t I use variables of type int64/uint64 as block parameter in Simulink

MATLAB: How to use SS_UINT64 and SS_INT64 port data types in the S Function

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