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Built-in Self-test
A built-in self-test (BIST) or built-in test (BIT) is a mechanism that permits a machine to test itself. Engineers design BISTs to meet requirements such as: *high reliability *lower repair cycle times or constraints such as: *limited technician accessibility *cost of testing during manufacture The main purpose of BIST is to reduce the complexity, and thereby decrease the cost and reduce reliance upon external (pattern-programmed) test equipment. BIST reduces cost in two ways: # reduces test-cycle duration # reduces the complexity of the test/probe setup, by reducing the number of I/O signals that must be driven/examined under tester control. Both lead to a reduction in hourly charges for automated test equipment (ATE) service. Applications BIST is commonly placed in weapons, avionics, medical devices, automotive electronics, complex machinery of all types, unattended machinery of all types, and integrated circuits. Automotive Automotive tests itself to enhance safety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Engineering
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time. The reliability function is theoretically defined as the probability of success at time t, which is denoted R(t). This probability is estimated from detailed (physics of failure) analysis, previous data sets or through reliability testing and reliability modelling. Availability, testability, maintainability and maintenance, repair and operations, maintenance are often defined as a part of "reliability engineering" in reliability programs. Reliability often plays the key role in the cost-effectiveness of systems. Reliability engineering deals with the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SONET
Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). At low transmission rates data can also be transferred via an electrical interface. The method was developed to replace the plesiochronous digital hierarchy (PDH) system for transporting large amounts of telephone calls and data traffic over the same fiber without the problems of synchronization. SONET and SDH, which are essentially the same, were originally designed to transport circuit mode communications (e.g., DS1, DS3) from a variety of different sources, but they were primarily designed to support real-time, uncompressed, circuit-switched voice encoded in PCM format. The primary difficulty in doing this prior to SONET/SDH was that the synchronization sources of these various circuits were different. This meant that each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Equipment
Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film), a Russian film * ''Test'' (group), a jazz collective * ''Tests'' (album), a 1998 album by The Microphones Computing * .test, a reserved top-level domain * test (Unix), a Unix command for evaluating conditional expressions * TEST (x86 instruction), an x86 assembly language instruction People * Test (wrestler), ring name for Andrew Martin (1975–2009), Canadian professional wrestler * John Test (1771–1849), American politician * Zack Test (born 1989), American rugby union player Science and technology * Proof test * Stress testing * Test (biology), the shell of sea urchins and certain microorganisms * Test equipment Sports * Test cricket, a series of matches played by two national representative teams * Test match (rugby league), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watchdog Timer
A watchdog timer (sometimes called a ''computer operating properly'' or ''COP'' timer, or simply a ''watchdog'') is an electronic or software timer that is used to detect and recover from computer malfunctions. Watchdog timers are widely used in computers to facilitate automatic correction of temporary hardware faults, and to prevent errant or malevolent software from disrupting system operation. During normal operation, the computer regularly restarts the watchdog timer to prevent it from elapsing, or "timing out". If, due to a hardware fault or program error, the computer fails to restart the watchdog, the timer will elapse and generate a timeout signal. The timeout signal is used to initiate corrective actions. The corrective actions typically include placing the computer and associated hardware in a safe state and invoking a computer reboot. Microcontrollers often include an integrated, on-chip watchdog. In other computers the watchdog may reside in a nearby chip that connec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Engineering
Safety engineering is an engineering discipline which assures that engineered systems provide acceptable levels of safety. It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering. Safety engineering assures that a life-critical system behaves as needed, even when components fail. Analysis techniques Analysis techniques can be split into two categories: qualitative and quantitative methods. Both approaches share the goal of finding causal dependencies between a hazard on system level and failures of individual components. Qualitative approaches focus on the question "What must go wrong, such that a system hazard may occur?", while quantitative methods aim at providing estimations about probabilities, rates and/or severity of consequences. The complexity of the technical systems such as Improvements of Design and Materials, Planned Inspections, Fool-proof design, and Backup Redundancy decreases risk and increases the cost. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Engineering
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycles. At its core, systems engineering utilizes systems thinking principles to organize this body of knowledge. The individual outcome of such efforts, an engineered system, can be defined as a combination of components that work in synergy to collectively perform a useful function. Issues such as requirements engineering, reliability, logistics, coordination of different teams, testing and evaluation, maintainability and many other disciplines necessary for successful system design, development, implementation, and ultimate decommission become more difficult when dealing with large or complex projects. Systems engineering deals with work-processes, optimization methods, and risk management tools in such projects. It overlaps technical and human-centered disciplines such as industrial engineering, prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embedded System
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use today. , it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems. Modern embedded systems are often based on microcontrollers (i.e. microprocessors with integrated memory and peripheral interfaces), but ordinary microprocessors (using external chips for memory and peripheral interface circuits) are also common, especially in more complex systems. In either case, the processor(s) used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Built-in Self-test
Logic built-in self-test (or LBIST) is a form of built-in self-test (BIST) in which hardware and/or software is built into integrated circuits allowing them to test their own operation, as opposed to reliance on external automated test equipment. Advantages The main advantage of LBIST is the ability to test internal circuits having no direct connections to external pins, and thus unreachable by external automated test equipment. Another advantage is the ability to trigger the LBIST of an integrated circuit while running a built-in self test or power-on self test of the finished product. Disadvantages LBIST that requires additional circuitry (or read-only memory) increases the cost of the integrated circuit. LBIST that only requires temporary changes to programmable logic or rewritable memory avoids this extra cost, but requires more time to first program in the BIST and then to remove it and program in the final configuration. Another disadvantage of LBIST is the possibility that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Built-in Test Equipment
Built-in test equipment (BITE) for avionics primarily refers to passive fault management and diagnosis equipment built into airborne systems to support maintenance processes. Built-in test equipment includes multimeters, oscilloscopes, discharge probes, and frequency generators that are provided as part of the system to enable testing and perform diagnostics. The acronym BIT is often used for this same function or, more specifically, in reference to the individual tests. BIT often includes: * The detection of the fault * The accommodation of the fault (how the system actively responds to the fault) * The annunciation or logging of the fault to warn of possible effects and/or aid in troubleshooting the faulty equipment. Functionality * Analysis of failure monitoring results * Reporting and memorization of failures * Management of tests See also *Built-in self-test *Logic built-in self-test Logic built-in self-test (or LBIST) is a form of built-in self-test (BIST) in which hardwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LBIST
Logic built-in self-test (or LBIST) is a form of built-in self-test (BIST) in which hardware and/or software is built into integrated circuits allowing them to test their own operation, as opposed to reliance on external automated test equipment. Advantages The main advantage of LBIST is the ability to test internal circuits having no direct connections to external pins, and thus unreachable by external automated test equipment. Another advantage is the ability to trigger the LBIST of an integrated circuit while running a built-in self test or power-on self test of the finished product. Disadvantages LBIST that requires additional circuitry (or read-only memory) increases the cost of the integrated circuit. LBIST that only requires temporary changes to programmable logic or rewritable memory avoids this extra cost, but requires more time to first program in the BIST and then to remove it and program in the final configuration. Another disadvantage of LBIST is the possibility that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PBIST
Programmable Built-In Self-Test (PBIST) is a memory DFT feature that incorporates all the required test systems into the chip itself. The test systems implemented on-chip are as follows: * algorithmic address generator * algorithmic data generator * program storage unit * loop control mechanisms PBIST was originally adopted by large memory chips that have high pin counts and operate at high frequencies, thereby exceeding the capability of production testers. The purpose of PBIST is to avoid developing and buying more sophisticated and very expensive testers. The interface between PBIST, which is internal to the processor, and the external tester environment is through the standard JTAG TAP controller pins. Algorithms and controls are fed into the chip through the TAP controller's Test Data Input (TDI) pin. The final result of the PBIST test is read out through the Test Data Output (TDO) pin. PBIST supports the entire algorithmic memory testing requirements imposed by the productio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minuteman Missile
The LGM-30 Minuteman is an American land-based intercontinental ballistic missile (ICBM) in service with the Air Force Global Strike Command. , the LGM-30G Minuteman III version is the only land-based ICBM in service in the United States and represents the land leg of the U.S. nuclear triad, along with the Trident submarine-launched ballistic missile (SLBM) and nuclear weapons carried by long-range strategic bombers. Development of the Minuteman began in the mid-1950s when basic research indicated that a solid-fuel rocket motor could stand ready to launch for long periods of time, in contrast to liquid-fueled rockets that required fueling before launch and so might be destroyed in a surprise attack. The missile was named for the colonial minutemen of the American Revolutionary War, who could be ready to fight on short notice. The Minuteman entered service in 1962 as a deterrence weapon that could hit Soviet cities with a second strike and countervalue counterattack if the U.S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
