WORK library

No claim to original U.S. Government works Library of Congress Card Number 1-57491-120-1 Printed in the United States of America 1234567890 Printed on acid-free paper... 

The archive is important because it provides context for work—not merely a way of getting at a particular known piece of work. Libraries provide that context by bringing together the patchwork of various pubUshers and models, and then deal with the frustrations of trying to piece it all together. Libraries work toward a grand vision of a richer and more interoperable context. Gold said. 

L. M. PETRIE et al., NITAWL (Nordheim s Integral Treatment and Working Library) AMPX, ORNL/TM-3706, Oak Ridge National Lab. (Mw. 1976). 

Example 10.3 shows how one can achieve the required functionality via a procedure call. The procedure latch proc is defined in package my pack. This package is analyzed into the work library. When a procedure call to latch proc is made in the VHDL code, the map to cntity directive in the procedure latch proc ensures that the LDl latch is inferred from the technology library. Thus, the procedure implies a certain implementation. This ensures that the required functionality is achieved using the desired libraiy cell. Expanding on this approach, one can develop a library of procedures and functions and easily force the inference of certain technology specific implementations during synthesis. 

Engineering with Glass, Corning Glass Works, Library of Congress Catalog Card No. 62-19567. 

There is one only type of working library, called WORK. This contains all the design units of the present design that have been compiled. It could therefore store entities, architectures and packages. 

So how can a design unit access a library and its contents First, there are a number of design units that are implicitly visible to every other design unit. These are the STANDARD package in the STD library and all entities, architectures and packages contained in the WORK library. If these were not implicitly visible, every design unit would need to be preceded by the following statements ... 

All package and entity declarations in the working library, WORK, and the STANDARD package are implicitly visible when the current design unit is being compiled. Any package or library that is visible to a primary unit is implicitly visible to the associated secondary unit. 

As the comments in Figure 4.8 explain, because the components are compiled and stored in the working library, they are automatically visible to this architecture. STRUCTURAL demonstrates the use of both component declarations and indirect instantiations. 

Figure 4.7 Nand gate dataflow descriptions. These are compiled and stored in the WORK library.

The entity declaration and architecture body of each component is shown in Figure 4.9. Again these descriptions are compiled and stored in the working library where the multiplexer architecture, STRUCTURAL2, can access them. Unlike STRUCTURAL , however, this architecture does not declare the components in its declarative part. Instead it uses a package declaration to store the component declarations. A Use clause is then required to... 

JKFF are user-defined versions of flip flops that are compiled into the working library. The compile-time options are effectively the same as those shown in section 4.2.3 (barring specific names). 

Remember that the package STATE DEFN must be compiled and stored in the working library before SEQUENCE-BEHAVIOUR is s)mthesized. 

The procedure that describes the operation of the random sequence generator is stored in a package called CONTROL.LOGIC in the working library. The details of the prcKedure itself are discussed below. 

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