State (computer science)

About: State (computer science) is a research topic. Over the lifetime, 24436 publications have been published within this topic receiving 225733 citations.

Internet Worm and Virus Protection in Dynamically Reconfigurable Hardware

Abstract: The security of the Internet can be improved using Programmable Logic Devices (PLDs). A platform has been implemented that actively scans and filters Internet traffic for Internet worms and viruses at multi-Gigabit/second rates using the Field-programmable Port Extender (FPX). Modular components implemented with Field Programmable Gate Array (FPGA) logic on the FPX process packet headers and scan for signatures of malicious software (malware) carried in packet payloads. FPGA logic is used to implement circuits that track the state of Internet flows and search for regular expressions and fixed-strings that appear in the content of packets. The FPX contains logic that allows modules to be dynamically reconfigured to scan for new signatures. Network-wide protection is achieved by the deployment of multiple systems throughout the Internet.

Path dependent power modeling

Abstract: A system and method for modeling the power consumed by a logic cell in a computer controlled power estimation process estimating the power consumed for an integrated circuit represented by logic cells and connections between cells. The present invention models power consumption within a logic cell associated with a particular pin (e.g., input, output, bidirectional, internal) based on a prescribed condition of the state of signals that exist contemporaneously with a signal transition on the particular pin. This is referred to as state dependent power modeling. A different power consumption value can be provided for each different modeled state. The logic cells and the power consumption model for them are stored in a logic cell "library" within the computer system. State dependent power modeling of the present invention allows library designers to specify a different set of power values depending on the condition of one or more pins of the library cell (e.g., the library's representation of the logic cell). Specifically, library designers are allowed to specify a "when" condition with their power tables. To take advantage of the state dependent power modeling, library designers can specify multiple power tables in the library cell with different when conditions. State dependent power modeling is important for those cells for which a certain condition of the pins makes the logic cell consume more or less power than the otherwise recorded "average" power rating used in conventional libraries. Examples of these cells are random access memories (RAMs), input/output cells (IOs), and enabled flip-flops.

System and method for maintaining persistent state data

Abstract: A system and method for maintaining persistent data during an unexpected power loss uses a memory controller and a supplemental power source. An entity running on the computer, for example, an application program, a utility, the operating system or other entity, may identify data for preservation using an application program interface. The application program interface may be provided by the memory controller. A sensor determines when an unexpected power loss has occurred and signals the memory controller. Using power from the supplemental power source, i.e. a battery or capacitor, the memory controller copies the identified data to a non-volatile memory. The memory controller may set a flag to indicate that preserved data is available for later recovery.

Automatic State-Based Test Generation Using Genetic Algorithms

Abstract: Although a lot of research has been done in the field of state-based testing, the automatic generation of test cases from a functional specification in the form of a state machine is not straightforward. This paper investigates the use of genetic algorithms in test data generation for the chosen paths in the state machine, so that the input parameters provided to the methods trigger the specified transitions.

Method and apparatus for controlling usage of a programmable computing machine

Abstract: A method for controlling usage of a programmable computing machine which operates in accordance with uncoded or published machine language operation codes including uniquely encoding the uncoded operation codes of instructions of a program to be used on the computing machine as a function of location of the instructions in memory and as a function of machine state, and adding to the machine a decoder that decodes only the uniquely encoded operation codes. Apparatus for controlling usage of a programmable computing machine which operates in response to uncoded or published machine language operation codes including memories which store machine user created programs and operating system programs, in which each program has instructions with uncoded and encoded operation codes, decoders to decode the encoded operation codes of the instructions of the user created program and the encoded operation codes of the instructions of the operating system program, and a circuit to execute the instructions of the user created program and the operating system program having the decoded and the uncoded operation codes.