Each field and interrupt in vhdmmio can register scalar and vector inputs and outputs, as well as generics. This configuration structure determines how these interfaces are exposed in the entity.

By default, the ports are grouped by field/interrupt into records while generics are flattened, but either can be overridden. It is also possible to group multiple fields/interrupts together in a single record.

This structure supports the following configuration keys.

Name of the group record used for ports, if any. The ports for any objects that share the same non-null group tag are combined into a single record pair (in and out).

The following values are supported:

• null (default): port grouping is determined by the global default.

• no: ports are not grouped in an additional record.

• a string matching [a-zA-Z][a-zA-Z0-9_]*: ports are grouped in a record with the specified name.

This key is optional unless required by context. If not specified, the default value (null) is used.

Whether the ports for this object should be flattened or combined in a record (pair).

The following values are supported:

• null (default): port flattening is determined by the global default.

• no: all ports needed for this object are combined in a record specific to the object. If group is specified in addition, there will be two levels of records. For arrays, an array of records is created.

• record: The record mentioned above is flattened out. For array objects, std_logic ports become std_logic_arrays (ascending range), and std_logic_vector ports become an array (ascending range) of an appropriately sized std_logic_vector.

• yes: All port types are flattened to std_logics or std_logic_vectors. std_logic_vector ports for array objects are simply concatenated using the customary descending range, with the lowest-indexed field in the least-significant position.

This key is optional unless required by context. If not specified, the default value (null) is used.

Same as group, but for generics.

The following values are supported:

• null (default): generic grouping is determined by the global default.

• no: generics are not grouped in an additional record.

• a string matching [a-zA-Z][a-zA-Z0-9_]*: generics are grouped in a record with the specified name.

This key is optional unless required by context. If not specified, the default value (null) is used.

Same as flatten, but for generics.

The following values are supported:

• null (default): generic flattening is determined by the global default.

• record: generics are not grouped in a record, but arrays remain regular arrays (possibly of std_logic_vectors).

• yes: as above, but all std_logic-based generics are flattened to single std_logics or std_logic_vector`s. Other primitive types still receive their own custom array type for array objects.

• no: all generics needed for this object are combined in a record specific to the object.

This key is optional unless required by context. If not specified, the default value (null) is used.