Abstract: A conservative algorithm for pruning data paths during logic circuit timing verification is disclosed. It uses the correlation between delays on data paths and clock paths in order to prune non-critical data paths during the traversal of the network. Subnetworks are identified in the larger network. Pruning data consisting of the minimum possible delay across all possible paths through the subnetwork, the deskewing clocks, the clock arrival times, and hold times at the synchronizers in the subnetwork are identified the first time each subnetwork is analyzed. In later analysis, the pruning data stored for each subnetwork is used to determine whether a data path can be pruned. A path can be pruned if it is shown to be race-free based on the pruning data. In this way, non-critical paths need only be traced once during timing verification.

Abstract: A technique for controlling a power supply involves receiving a programming signal that indicates a power supply output voltage limit, activating the power supply such that the power supply provides a power supply output voltage according to a power supply threshold voltage, generating a tracking signal that tracks the programming signal, and generating a compare signal according to the tracking signal and an actual value of the power supply output voltage. The technique further involves comparing the compare signal to a protection threshold voltage, maintaining activation of the power supply when the compare signal is less than the protection threshold voltage, and deactivating the power supply when the compare signal is greater than the protection threshold voltage. The protection threshold voltage is independent of the power supply threshold voltage.

Abstract: The disclosed system updates client systems regarding changes in a shared display region on a server using compressed graphical display information. The disclosed system compares a first bit map with a second bit map to generate a difference array. The difference array includes indication of each bit in the second bit map having a different value than in the first bit map. The system then transmits the difference array to a client system if at least one bit in the second bit map is different from a corresponding bit in the first bit map. In a further aspect of the disclosed system, the system run length encodes the difference array prior to transmitting if the second bit map is different from the first bit map to generate a run length encoded difference array. The client system generates an updated bit map based on an initial bit map and the difference array. The client system displays the shared region using the updated bit map.

Abstract: In a computer system, an instrumented program associated with a first paging table is stored in a memory. The memory also stores an instrumented version of the uninstrumented program associated with a second paging table. The instructions of the uninstrumented and instrumented programs are stored at identical relative addresses. The instrumented programs also includes one word instrumentation points and instrumentation routines to monitor the performance of the computer system. Activating the first paging table causes the uninstrumented program to execute, and activating, in response to a single, the second paging table causes the instrumented program to execute. The instrumentation points cause execution flow to be routed through a gap between word aligned procedures of the program to a routing table, and then instrumentation routines. The gap includes instructions which randomly distributes the execution flow through the routing table.

Abstract: A computer system comprising one or more information source modules and information display modules interconnected by a communications link. The information source module transmits, and the information display module receives, original information items using a peer-to-peer message transmission protocol. Thereafter, the information source module transmits update information items to the information display modules at one time using a multi-cast information transmission mechanism. In the multi-cast information transmission mechanism, an information display module determines when it has missed an update information message, waits a selected backoff delay time, and transmits a retransmission request for update information messages whose retransmission has not been requested by other information display modules during the backoff delay period.

Abstract: A method and apparatus to reduce bus usage and to increase resource locking protocol compatibility within a heterogeneous processing environment. Lock indicators are maintained in stores designated as lock registers and access to a resource is gained by any processor depending upon the status of a lock register associated with that resource. Access to a locked resource is barred to all but the locking processor, and only the processor which has set a lock can use or release that locked resource. A lock register controller controls the contents of the lock registers. A given processor P1-PN is identified by a unique ID vector G1-GN. These vectors are used to indicate both that a resource is locked and to indicate the identity of the locking processor. An unlocked resource is identified by a status vector (G.O slashed.).

Abstract: A method of using additives with silica-based slurries to enhance metal selectivity in polishing metallic materials utilizing a chemical-mechanical polishing (CMP) process. Additives are used with silica-based slurries to passivate a dielectric surface, such as a silicon dioxide (SiO.sub.2) surface, of a semiconductor wafer so that dielectric removal rate is reduced when CMP is applied. The additive is comprised of at least a polar component and an apolar component. The additive interacts with the surface silanol group of the SiO.sub.2 surface to inhibit particles of the silica-based slurry from interacting with hydroxyl molecules of the surface silanol group. By applying a surface passivation layer on the SiO.sub.2 surface, erosion of the SiO.sub.2 surface is reduced. However, the metallic surface is not influenced significantly by the additive, so that the selectivity of metal removal over oxide removal is enhanced.

Abstract: A system for managing an assemblage of entities. The entities interface within the assemblage for control of primary information handling functions and further interface with the system to permit the carrying out of management functions. The system includes management modules adapted to carry out management functions by independently interpreting and executing commands, a kernel including a table of dispatch pointers for directing the commands to the respective modules in which they are to be interpreted and executed, and an enroller for enrolling new modules into the system by adding further pointers to the table.

Abstract: A system for retrieval of documents in a client-server environment is disclosed. The system provides compatibility between an attribute based document display system and diverse query languages within remote document repositories. The system includes a local process running on a client module, and a remote process running within each document repository. Each remote process is designed for the particular model of computer used for the server. Each remote process executes a System Query Language (SQL) used by a particular database program running on the server. A particular server may have several database programs implemented thereon, and each database program has a dedicated remote process, where the remote process is matched to the particular database program. The local process on the user's workstation launches inquiries in a first format on the network. Each remote process receiving an inquiry translates the received inquiry into the System Query Language required by its server and its database program.

Abstract: A system for managing an assemblage of entities. The entities interface within the assemblage for control of primary information handling functions and further interface with the system to permit the carrying out of management functions. The system includes management modules adapted to carry out management functions by independently interpreting and executing commands, a kernel including a table of dispatch pointers for directing the commands to the respective modules in which they are to be interpreted and executed, and an enroller for enrolling new modules into the system by adding further pointers to the table.

Abstract: A scheduler with admissions control in a continuous media file server is presented. The scheduler supports multiple classes of tasks with diverse performance requirements. The scheduler is based on a combination of rate-monotonic and weighted round-robin scheduling schemes. Scheduling is accomplished in a hierarchical manner. Isochronous tasks have the highest priority and are scheduled first followed by real-time and general-purpose tasks. Isochronous tasks run periodically and are invoked by a timer interrupt set for each task. After scheduling the isochronous tasks, the scheduler alternates between the real-time tasks and the general-purpose tasks using a weighted round-robin scheme.

Abstract: A system for displaying documents on a computer controlled display device is disclosed. The system displays documents either in a completely free-form, user controlled configuration or as strands, such that documents in a strand follow a strand path. The strand path is a two dimensional line through a three dimensional display space. The documents displayed on the strand are known as child documents, and each strand also has a parent document. Various constraints defining the strand are associated with the parent document, including a strand function defining the strand path, minimum and maximum separation constraints defining the distance between the child documents on the strand, and an origin constraint defining the positional relationship of the strand path to the screen object of the parent document.

Abstract: An encryption system employing a one-time key-pad uses a shared secret number and a one-way hash function with which both the originator and recipient of a message generate successive segments of a key-pad to encrypt and decrypt the message respectively. In one arrangement each key-pad segment is generated by applying the hash function to a combination of the secret number and the previous key-pad segment. In the other embodiment of the invention, each key-pad section is generated by applying the one-way hash function to a combination of the secret number and a corresponding segment of the ciphertext version of the message.

Abstract: Frame processing apparatus, and a related method for its operation, for use in a station connected to a token ring network, to ensure rapid stripping of frames from the network without reference to source addresses in the frames, and in spite of the possible presence of extraneous no-owner frames on the network. The adverse effects of extraneous no-owner frames are avoided by any of three techniques. First, transmitted information frames are preceded by a start strip delimiter frame and followed by an end strip delimiter frame. The process strips all incoming frames (except tokens and ring initialization frames, which are specially handled), but does not count the stripped frames until the start strip delimiter frame is detected. Therefore, extraneous frames preceding the transmitted information frames will be stripped but not counted, and all of the transmitted frames will be stripped. In another approach, an estimated stripping time is used to terminate stripping.

Abstract: A system for stripping frames transmitted by a station on a token ring network is disclosed. During operation of the system, the station receives a grant of permission to transmit onto the network. In an example embodiment, the grant of permission is a token. After receipt of the grant of permission to transmit, the station transmits one or more information frames onto the network. Upon transmission of the information frames, the station stops forwarding frames received from the network, thus removing received frames from the network. Removing received frames from the network is referred to as `stripping`. Following transmission of the information frames, the station transmits an end strip delimiter frame onto the network. Upon receipt of the end strip delimiter frame, the station terminates stripping. In an example embodiment, the system is used in a bridge station, the bridge station connecting a first network with a second network.

Abstract: A signature system, such as an El Gamal or DSS system, involving the use of a long-term secret number and a per-message secret number generates the per-message secret number without the use of a random number generator or non-volatile storage. The per-message secret number is generated by applying a one-way hash function to a combination of the long-term secret number and the message itself.

Abstract: Two devices HR and FR are coupled to a bus with a common memory via a port controller. Device HR requires a high (or maximum) average rate of access, device FR requires a fast response (minimum latency) in establishing access. Request signals HRQ, FRQ from the devices are latched by latches 20 and 21, passed as HRX, FRX through an arbitration or resolver circuit 22 as HRY, FRY to a sequence control unit 23 to initiate an access cycle. Cycle timing is determined by a delay line timebase circuit 24, which responds to a single change of level of a signal DLY (in either direction). Latch 21, when set, generates an request pending signal FRRP which is fed to the HR device to cause it to increase its cycle length so that the FR access cycle will finish before the next HR access cycle is initiated.

Abstract: A frame having a desired destination address written into the destination address field of the frame is transmitted onto a first communications system, the frame is received by the apparatus, the frame is transmitted by the apparatus onto a second communications system with a second destination address written into the destination address field of the second frame, and also the desired destination address is written into a predetermined field of the second frame along with an indicator. The indicator is capable if being interpreted by a receiving station to mean that the desired destination address is written into the predetermined field of the second frame.

Abstract: An apparatus for storing and retrieving data acts as an interface between modules such as data collection devices and data analysis tools. The apparatus provides the capability of maintaining a data standard so the number of translation tools needed to transfer data from one module to another is reduced. The apparatus maintains the data standard by means for storing a configuration data structure having table data structures. The configuration data structure and the table data structure define a data model. The data model is editable. Complex, as well as simple, items may be stored in the table data structure.