VHDL Language Support Exceptions

VHDL Language Support Exceptions - 2021.2 English

Vivado Design Suite User Guide: Logic Simulation (UG900)

Document ID

UG900

Release Date

2021-10-22

Version

2021.2 English

Certain language constructs are not supported by the Vivado simulator. The following table lists the VHDL language support exceptions.

Table 1. VHDL Language Support Exceptions
Supported VHDL Construct	Exceptions
`abstract_literal`	Floating point expressed as based literals are not supported.
`alias_declaration`	Alias to non-objects are in general not supported; particularly the following: Alias of an alias Alias declaration without subtype_indication Signature on alias declarations Operator symbol as alias_designator Alias of an operator symbol Character literals as alias designators
`alias_designator`	Operator_symbol as alias_designator Character_literal as alias_designator
`association_element`	Globally, locally static range is acceptable for taking slice of an actual in an association element.
`attribute_name`	Signature after prefix is not supported.
`binding_indication`	Binding_indication without use of entity_aspect is not supported.
`bit_string_literal`	Empty bit_string_literal (" ") is not supported.
`block_statement`	Guard_expression is not supported; for example, guarded blocks, guarded signals, guarded targets, and guarded assignments are not supported.
`choice`	Aggregate used as choice in case statement is not supported.
`concurrent_assertion_statement`	Postponed is not supported.
`concurrent_signal_assignment_statement`	Postponed is not supported.
`concurrent_statement`	Concurrent procedure call containing wait statement is not supported.
`conditional_signal_assignment`	Keyword guarded as part of options is not supported as there is no supported for guarded signal assignment.
`configuration_declaration`	Non locally static for generate index used in configuration is not supported.
`entity_class`	Literals, unit, file, and group as entity class are not supported.
`entity_class_entry`	Optional <> intended for use with group templates is not supported.
`file_logical_name`	Although `file_logical_name` is allowed to be any wild expression evaluating to a string value, only string literal and identifier is acceptable as file name.
`function_call`	Slicing, indexing, and selection of formals is not supported in a named parameter association within a `function_call`.
`instantiated_unit`	Direct configuration instantiation is not supported.
`mode`	Linkage and Buffer ports are not supported completely.
`options`	Guarded is not supported.
`primary`	At places where primary is used, allocator is expanded there.
`procedure_call`	Slicing, indexing, and selection of formals is not supported in a named parameter association within a `procedure_call`.
`process_statement`	Postponed processes are not supported.
`selected_signal_assignment`	The `guarded` keyword as part of options is not supported as there is no support for guarded signal assignment.
`signal_declaration`	The `signal_kind` is not supported. The `signal_kind` is used for declaring guarded signals, which are not supported.
`subtype_indication`	Resolved subtype of composites (arrays and records) is not supported.
`waveform`	Unaffected is not supported.
`waveform_element`	Null waveform element is not supported as it only has relevance in the context of guarded signals.