ENTITY - Architecture Entity Description

Syntax

ENTITY entity_type_name library_name (

EXTENDS ( abstract_type )
DESCRIPTION ("description")
INCLUDE ("compilation options")
STATES (state1, ...)
PARAMS ( modifier reference_parameter, ... )
PORTS ( port, ... )

)

Synopsis

The ENTITY construct enables the creation of a basic type of the architecture.

entity_type_name str - The name of the type of entity to be created. This is used to create instances of the component in the architecture, and to identify the correct simulation code and icon.
library_name str (optional) - The name of library from which the behaviour is coming from. If the library_name is not specified, then the user must provide a .hase description of the behaviour. See library components for a description of components which are currently in the HASE library.
abstract_type str (optional) - The name of the abstract entity this entity is intended to inherit from. The abstract entity must have previously been defined in the entity library.
description str - A description of an aspect of the entity.
compilation options str (optional) - give additional compilation information for this specific entity. For example, paths to find header files can be specified (e.g. -I${HASEDIR}/distributions/includejava).
statei str (optional) - This is an explicit declaration of the entity's states. It provides the entity with a variable called my_state which can take values declared in the STATES statement. This declaration was previously performed by defining an external enumerate parameter. Consequently, the entity was dependent on the existence of the external ENUM type, the reusability was reduced. In addition, doing so, gif images can be associated to each state in the ELF declaration making the ENT_ICON mode useless and making redundant the gif information in edl file.
modifier read_only or static (optional) - There are two possible optional modifiers. The static modifier must be used when the parameter is to be shared by every instances of this entity. The read_only modifier is used when a parameter is declared which must not be modified by the user via the gui, the value can be updated only by the instance of the entity. In the example below, the hit parameter is declared read_only. The user cannot decide what the number of hits is.
reference_parameter - This section of the entity definition describes the parameters that are associated with the entity. For example, a memory entity may have an array associated with it to hold the contents, and integer to hold the access time of the component. Careful selection of the parameters could result in reusable components. For example a cache entity might have parameters for its size, associativity and access time. See the reference section.
port - This section of the entity definition describes the ports of the entity. The ports are the entities means of communicating with the other entities. Ports of different entities are connected together to form a communication channel.

Example

ENTITY Cache (

DESCRIPTION ( "A generic parameterized cache" )
PARAMS (

RARRAY ( Memory, cache_contents )
RINT ( access_time, 2 )
RENUM ( Associativity, cache_assoc, 0 )
read_only RINT ( hit, 0 )

)
PORTS (

PORT ( to_cpu, LinkData, SOURCE )
PORT ( from_cpu, LinkData, DESTINATION )
PORT ( to_main_mem, LinkData, SOURCE )
PORT ( from_main_mem, LinkData, DESTINATION )

)



PROJECT(

	    
	    
	    PREAMBLE(
			 
			 NAME "project_name"

			 DIRECTORY "working_directory"

			 AUTHOR "project_author"

			 VERSION ver

			 DESCRIPTION "project_description"

			 
			 COMPILER "compiler_name"

			 LINK "linker_name"

			 LIBRARY "library_options"

			 EXTERN lib1, ...
			       
			 )

      PARAMLIB(parameter, ...)

      GLOBALS(reference_parameter, ...)

      ENTITYLIB(
         entity_definition | higher_entity_definition | 
         mesh_entity | abstract_entity, ...)

      STRUCTURE(architecture_entity | communication_channel , ... )
   
)

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