Specify whether to use system-defined or user-defined type definitions for multiword data types in generated code.
Category: Code Generation > Interface
Default:
System defined
System definedUse the default system type definitions for multiword data types in generated
code. During code generation, if multiword usage is detected, multiword type
definitions are generated into the file multiword_types.h.
User definedAllows you to control how multiword type definitions are handled during the code
generation process. Selecting this value enables the associated parameter
Maximum word length, which allows you to specify a
maximum word length, in bits, for which the code generation process generates
multiword type definitions into the file multiword_types.h. The
default maximum word length is 256. If you select 0, multiword type definitions are
not generated into the file multiword_types.h.
The maximum word length for multiword types only determines the type definitions
generated and does not impact the efficiency of the generated code. If the maximum
word length for multiword types is set to 0 or too small, an error occurs when the
generated code is compiled. This error is caused by the generated code using a type
that does not have the required type definition. To resolve the error, increase the
maximum word length and regenerate the code. If the maximum word length for multiword
types is larger than required, then multiword_types.h might contain
unused type definitions. Unused type definitions do not consume target
resources.
Adding a model to a model hierarchy or changing an existing model in the hierarchy
can result in updates to the shared multiword_types.h file during
code generation. These updates occur when the new model uses multiword types of length
greater than those of the other models. You must then recompile and, depending on your
development process, reverify previously generated code. To prevent updates to
multiword_types.h, determine a maximum word length sufficiently big
to cover the needs of all models in the hierarchy.
Configure every model in the hierarchy to use that same maximum word length.
The majority of embedded designs do not need multiword types. By setting maximum word length for multiword types to 0, you can prevent use of multiword variables on the target. If you use multiword variables with a maximum word length that is 0 or smaller than required, you are alerted with an error when the generated code is compiled.
This parameter appears only for ERT-based targets.
This parameter requires an Embedded Coder® license when generating code.
Selecting the value User defined for this parameter
enables the associated parameter Maximum word length.
| Parameter: MultiwordTypeDef |
| Type: character vector |
Value:
'System defined' | 'User defined' |
Default:
'System defined'
|
| Application | Setting |
|---|---|
| Debugging | No impact |
| Traceability | No impact |
| Efficiency | No impact |
| Safety precaution | No recommendation |