VOV Design Flow Manager

Fewer design cycles, faster

VOV automatically captures all dependencies between files and tools, using a technique called "run-time tracing," which is briefly explained in the rest of this page. For more information, please refer to the bibliography.

VOV has been designed to be as non-intrusive as possible. In fact, it is completely possible for VOV to remain completely invisible as long as no errors are made. Designers can continue to work exactly as they would if VOV did not exist. But if the designers try either to use invalid data or to overwrite valid data, VOV will offer a chance to limit the waste of time or data.

Errors can be avoided altogether if the designers use VOV to invoke the tools. Through the detailed knowledge of dependencies, VOV helps eliminate the design cycles caused by errors in the propagation of changes to the design files.

The dependency graph also represents all potential parallelism in the design flow. VOV distributes the jobs in parallel across the network. The use of computing resources is increased and the duration of each design cycle is reduced.

Benefits for the designer:

Benefits for the project leader:

  • Automatic tool scheduling and invocation to regain consistency of data after one or multiple changes
  • Management of computing resources like computers and floating licenses.
  • Low overhead
  • Archival, retrieval of methodologies
  • Command line, menu dirven and graphical user interface
  • Extension language (Tcl)
  • Generic interface to databases. Included are UNIX, AR, OCT (from UC-Berkeley)

    The dependency graph

    Designers of electronic systems produce thousands of files with help of their computer tools. The files depend on each other in complex ways. If a designer changes a file, that change must eventually propagate to all dependent files. If the propagation is incorrect, the design will be inconsistent and the consequences will be costly.

    VOV uses a technique called run-time tracing, which is based on the observation that only the tool knows accurately the dependencies implied by its use. VOV offers two ways for tools to communicate the dependency information at run-time:

    Encapsulation
    consists normally of a shell script that computes the run-time dependencies, communicates them to the dependency manager, and then calls the tool. It is a powerful technique that does not require any modification of the tool. For the many tools that have already been encapsulated, the encapsulation effort has gone from a few minutes to a few weeks of work, depending on the complexity of the tool.
    Integration
    is an option for those who have access to the source code of the tool; it is faster and easier than encapsulation. The VOV Integration Library (VIL) consists of 600 lines of C code distributed in source format.

    The integration library is passive if VOV is not running; the integrated tool behaves exactly as the original tool.

    The information produced by the tools is used by the VOV server to build the dependency graph, also called the design trace.

    Architecture

    The client/server architecture of VOV supports concurrent activities, team coordination, distributed data management, and distributed processing.

    The server is the UNIX process that manages the design trace. Depending on the operating system, the server can handle up to 250 clients simultaneously. There are four classes of clients:

    Tools
    connect to the server to declare their inputs and outputs, thus allowing the server to build the design trace.
    Users
    connect to the server to query and possibly modify the trace. There are four user interfaces avaliable.
    Slaves
    offer computing resources to the server. Whenever the server decides that some tool needs to be executed, it will search the list of slaves for the best one that can do the job.

    The slaves are processes running on the various machines in the local area network. They are an integral part of the network computing subsystem in VOV.

    Proxies
    contribute knowledge about databases.

    The server does not know anything about databases. All the knowledge is provided externally by means of these proxies. This allows VOV to work with any databases, not just with UNIX files.

    Since UNIX is always needed, support for UNIX has been moved back into the server.

    Archiving methodologies

    Useful and proven design methodologies can be archived and retrieved for reuse. The VOV assistant guides you through the library of existing methodologies and extracts data and flow information from them.

    Your makefiles and scripts can be useful to build the design trace. VOV can convert the trace into a makefile or a shell script.

    Many tools are already encapsulated

    Runtime Design Automation provides capsules for selected tools from Cadence, Exemplar Logic, interHDL, Model Technology, Synopsys, ViewLogic, and Xilinx, as well as for many UNIX utilities and C and C++ compilers.

    Platforms

    VOV is available on AIX, DEC-Alpha, HAL HP-UX, Linux, SunOS-4.x, Solaris-2.
    Back to index
    © Copyright 1996 Runtime Design Automation