Operator library mapping

Operations are mapped onto Boolean equations, and then onto combinational library modules. Variables are mapped onto registers only if they are declared as architectural registers, or if thqr are used in a loop otherwise, th r are implemented as wires. 

Selective operator to library mapping, where operators, such as -f or... 

Perform automatic behavioral optimizations. In-line expansion and operator to library mapping are transformations that are guided by the designer. Upon completion of these optional user-driven transformations, a suite of automatic behavioral transformations is performed to optimize the behavior. Note that these optimizations caimot be applied to a block model because of its declarative semantics (the list of optimizations is described in Section 3.3). Optimizations include compilo -like optimizations such as dead-code elimination and variable unfolding. 

COM does not have the equivalent of Java s reflection, relying instead on the type library. Consequently, scripting and other applications that require very late binding—in which even the method called is not compiled against an interface but is looked up at runtime—require explicit support in the component itself. Each component can support what are called dispatch interfaces, in which a client requests an operation by a number the component resolves the mapping from numbers to methods to invoke. COM uses outgoing interfaces to define events, just as JavaBeans uses its events. 

TABLE 1 Sample mappings of physics operators to GAMMA library objects and code... 

During the first quarter of the twentieth century, there were efforts to establish workshops in various archives and libraries through individual enterprise. One such endeavor was made by the Central Library in Barcelona, which sent selected technicians to the Vatican Library in Rome for training. Later, a small restoration laboratory was started in the Central Library, which, for the time, was one of the most advanced in the country (3). It remained active for some thirty-five years the operation ceased when its personnel were transferred to other duties. During the same era, the National Library in Madrid established a career field never heard of before Paper Restorer. The position was filled by a self-taught mender of engravings, documents, and maps, who on retirement was not replaced. 

It was realized some time ago that Richards method of optical comparison could be advantageously implemented in an interactive computer graphics system [30, 31]. The computer has access to data representing the electron density map and is capable of constructing a representation of the molecular model from a library describing the amino acid residues. The electron density map and the model are displayed on a cathode ray tube in a suitable form giving the illusion of three dimensions, and the operator instructs the computer to modify the model. The operator s commands tend to improve the perceived fit between map and model one of the functions of the computer is to maintain the model s bonded geometry. 

Allocation, which assigns each operation to a piece of hardware. Allocation involves both the selection of the type and quantity of hardware modules from a library (often called module assignment) and the mapping of each operation to the selected hardware. Allocation is sometimes called data path synthesis or data path allocation. 

Each time a library class introduces a data flow from a variable x to a variable y an edge (x,y) must be included in the OFG. Containers are an example of library classes that introduce external data flows, for instance, any Java class implementing the interface Collection or the interface Map. Object containers provide two basic operations affecting the OFG insert and extract for adding an object to a container and accessing an object in a container respectively. In the abstract program representation, insertion and extraction methods are associated with container objects. 

Figure 10.1 shows the DesignWare approach to achieving specific implementations. In the HDL code for a procedure similar to the latch proc procedure, if one were to use a map to operator directive instead of a map to cntity directive, the tool would infer the required synthetic operator on reading in the HDL to DC. One must then have a DesignWare library which provides the link between the operator and one or more synthetic modules. Each operator can be linked to multiple synthetic modules and each module can have multiple implementations. Based on the constraints specified, the DC ensures that the most optimal implementation is inferred. 

Example 10.4 shows the implementations for MULT UNS OP. Information about modules, operators and the implementations available can be obtained by executing the report synlib command. The synthetic operator MULT UNS OP is defined in the standard.sldb synthetic library. MULT UNS OP may be mapped to multiple synthetic modules which may have more than one implementation. The synthetic module DW02 mult has among other bindings, one binding b3 to MULT UNS OP. 

Now that the detailed architecture and the mapping of the algorithmic operations onto it are completed, it is possible to concentrate on the synthesis of the components in the next level in the hierarchy. In particular, the internal organisation of the controller (see e.g. [Zeg90]) and the detailed synthesis of the data paths in terms of the available HBB library [Not90] have to be taken care of to arrive at an optimised net-list which meets the clock specifications with... 

Operators in HardwareC, such as -I- or can be mapped into calls to library... 

The designs can use opoator mapping to specify the Types of hardware functional units that will be used to implement a design. If no mt ping is given, then by default operators are implemented as combinational logic. Because of the size of combinational multiplies and dividers, the multiply ( ) and divide (/) opeators are always mapped to library templates prior to structural synthesis in Hebe. 

Map Operators to library models. The description of a model may contain operators such as + and that can be synthesized in a variety of implementation styles. For example, an addition can be implemented using either a ripple-carry adder or a carry-lookahead addo. The designer can selectively replace operators by calls to specific models in a particular library. Any tq)erator that is not mapped to a library model will be implemented by default as combinational logic, with the exception of multiply ( ) and divide C / )> which must always be mapped. 

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