VHDL 1076-93/2000 Readme
Although the design goal for VHDL Simili
been full compliance with the VHDL standard, we have a few exceptions. Every
VHDL compiler we know of has some such set of exceptions -- the difference is
that we let you know what these exceptions are and hopefully we are not
penalized for this honesty.
exception listed below is categorized to indicate as to when this exception is
scheduled to be eliminated. In every instance, the compiler/simulator will issue and error
and prevent wrong results from being produced. If one or more of these features
are very important to you, please contact
us so we can accelerate its incorporation. Where the "Target
Release" indicates "Undetermined", this means that we wish to
implement these constructs but have not yet determined a timeframe.
|VHDL 93 Construct
|Disconnect statement not supported
|Individual associations to associate subprogram
parameters not supported. However, individual port/generic associations ARE
supported. We are not sure if any tool (commercial or otherwise)
|Type conversions on the formal part of the
association for subprograms in the case where the parameter is of class
SIGNAL. Most other tools do not support this either.
|The compiler does not currently check for the
validity of the keyword PURE/IMPURE before a subprogram definition.
However, from a simulation standpoint, the results will be correct.
|A concurrent procedure call made in an entity is
not checked to ensure that it is passive (that it does not modify any
signals). These functions however are executed correctly.
|The attributes 'INSTANCE_NAME and 'PATH_NAME
are not allowed during elaboration (mainly in declaration sections in
architectures). However, these attributes are
compliant during simulation (after elaboration). As a result, use of these attributes in the
declaration statements of entities and architectures will produce an
error. However, using them anywhere else will produce the desired results.
|The attributes 'DRIVING and 'DRIVING_VALUE are
not yet supported. These attributes attempt to query the driver of a given
signal for information about the driver. This feature has been implemented
but we are unsure about its accuracy under all circumstances and hence it
|User defined resolution functions for composite types.
Currently a user defined resolution function is only allowed on a scalar type.