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Scan Chain
Scan chain is a technique used in design for testing (DFT). The objective is to make testing easier by providing a simple way to set and observe every flip-flop in an IC. It simplifies the testing and debugging of complex digital systems. In scan-based design, flip-flops operate in two distinct modes: normal mode and scan mode. In normal mode, they support regular system operations. In scan mode, however, they are reconfigured into one long shift registers, known as Scan Chain. The basic structure of scan include the following set of signals in order to control and observe the scan mechanism. # Scan_in (SI) and Scan_out (SO) define the input and output of a scan chain. In a full scan mode usually each input drives only one chain and scan out observe one as well. # A scan enable (SE) pin is a special signal that is added to a design. When this signal is asserted, every flip-flop in the design is connected into a long shift register. # Clock signal which is used for controlling al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design For Testing
Design for testing or design for testability (DFT) consists of integrated circuit design techniques that add testability features to a hardware product design. The added features make it easier to develop and apply manufacturing tests to the designed hardware. The purpose of manufacturing tests is to validate that the product hardware contains no manufacturing defects that could adversely affect the product's correct functioning. Tests are applied at several steps in the hardware manufacturing flow and, for certain products, may also be used for hardware maintenance in the customer's environment. The tests are generally driven by test programs that execute using automatic test equipment (ATE) or, in the case of system maintenance, inside the assembled system itself. In addition to finding and indicating the presence of defects (i.e., the test fails), tests may be able to log diagnostic information about the nature of the encountered test fails. The diagnostic information can be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combinational Logic
In automata theory, combinational logic (also referred to as time-independent logic) is a type of digital logic that is implemented by Boolean circuits, where the output is a pure function of the present input only. This is in contrast to sequential logic, in which the output depends not only on the present input but also on the history of the input. In other words, sequential logic has ''memory'' while combinational logic does not. Combinational logic is used in computer circuits to perform Boolean algebra on input signals and on stored data. Practical computer circuits normally contain a mixture of combinational and sequential logic. For example, the part of an arithmetic logic unit, or ALU, that does mathematical calculations is constructed using combinational logic. Other circuits used in computers, such as half adders, full adders, half subtractors, full subtractors, multiplexers, demultiplexers, encoders and decoders are also made by using combinational logic. Prac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Peripheral Interface Bus
Serial Peripheral Interface (SPI) is a de facto standard (with many #Variations, variants) for Comparison of synchronous and asynchronous signalling, synchronous serial communication, used primarily in embedded systems for short-distance wired communication between integrated circuits. SPI follows a master–slave (technology), master–slave architecture, where a master device Signaling (telecommunications), orchestrates communication with one or more slave devices by driving the clock signal, clock and chip select signals. Some devices support changing master and slave roles on the fly. Motorola's original specification (from the early 1980s) uses four logic signals, aka lines or wires, to support full duplex communication. It is sometimes called a ''four-wire'' serial bus to contrast with Serial Peripheral Interface#Three-wire, three-wire variants which are half duplex, and with the ''two-wire'' I²C and 1-Wire serial buses. Typical #Applications, applications include interf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuit Design
Integrated circuit design, semiconductor design, chip design or IC design, is a sub-field of electronics engineering, encompassing the particular Boolean logic, logic and circuit design techniques required to design integrated circuits (ICs). An IC consists of miniaturized electronic components built into an electrical network on a monolithic semiconductor substrate by photolithography. IC design can be divided into the broad categories of Digital data, digital and analog electronics, analog IC design. Digital IC design is to produce components such as microprocessors, FPGAs, memories (Random-access memory, RAM, Read-only memory, ROM, and flash memory, flash) and digital Application-specific integrated circuit, ASICs. Digital design focuses on logical correctness, maximizing circuit density, and placing circuits so that clock and timing signals are routed efficiently. Analog IC design also has specializations in power IC design and Radio frequency, RF IC design. Analog IC design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design For Testing
Design for testing or design for testability (DFT) consists of integrated circuit design techniques that add testability features to a hardware product design. The added features make it easier to develop and apply manufacturing tests to the designed hardware. The purpose of manufacturing tests is to validate that the product hardware contains no manufacturing defects that could adversely affect the product's correct functioning. Tests are applied at several steps in the hardware manufacturing flow and, for certain products, may also be used for hardware maintenance in the customer's environment. The tests are generally driven by test programs that execute using automatic test equipment (ATE) or, in the case of system maintenance, inside the assembled system itself. In addition to finding and indicating the presence of defects (i.e., the test fails), tests may be able to log diagnostic information about the nature of the encountered test fails. The diagnostic information can be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System On A Chip
A system on a chip (SoC) is an integrated circuit that combines most or all key components of a computer or Electronics, electronic system onto a single microchip. Typically, an SoC includes a central processing unit (CPU) with computer memory, memory, input/output, and computer data storage#Secondary storage, data storage control functions, along with optional features like a graphics processing unit (GPU), Wi-Fi connectivity, and radio frequency processing. This high level of integration minimizes the need for separate, discrete components, thereby enhancing Performance per watt, power efficiency and simplifying device design. High-performance SoCs are often paired with dedicated memory, such as LPDDR, and flash storage chips, such as Universal Flash Storage, eUFS or eMMC, which may be stacked directly on top of the SoC in a Package on a package, package-on-package (PoP) configuration or placed nearby on the motherboard. Some SoCs also operate alongside specialized chips, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application-specific Integrated Circuit
An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-efficiency video codec. #Application-specific standard product, Application-specific standard product chips are intermediate between ASICs and industry standard integrated circuits like the 7400 series or the 4000 series. ASIC chips are typically semiconductor device fabrication, fabricated using metal–oxide–semiconductor (MOS) technology, as MOS integrated circuit chips. As feature sizes have shrunk and Electronic design automation, chip design tools improved over the years, the maximum complexity (and hence functionality) possible in an ASIC has grown from 5,000 logic gates to over 100 million. Modern ASICs often include entire Central processing unit, microprocessors, memory blocks including Read-only memory, ROM, Random-access memory, RAM, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Design Automation
Electronic design automation (EDA), also referred to as electronic computer-aided design (ECAD), is a category of software tools for designing Electronics, electronic systems such as integrated circuits and printed circuit boards. The tools work together in a Design flow (EDA), design flow that chip designers use to design and analyze entire semiconductor chips. Since a modern semiconductor chip can have billions of components, EDA tools are essential for their design; this article in particular describes EDA specifically with respect to integrated circuits (ICs). History Early days The earliest electronic design automation is attributed to IBM with the documentation of its IBM 700/7000 series, 700 series computers in the 1950s. Prior to the development of EDA, integrated circuits were designed by hand and manually laid out. Some advanced shops used geometric software to generate tapes for a Gerber format, Gerber photoplotter, responsible for generating a monochromatic ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test Compression
Test compression is a technique used to reduce the time and cost of testing integrated circuits. The first ICs were tested with test vectors created by hand. It proved very difficult to get good coverage of potential faults, so Design for testability (DFT) based on scan and automatic test pattern generation (ATPG) were developed to explicitly test each gate and path in a design. These techniques were very successful at creating high-quality vectors for manufacturing test, with excellent test coverage. However, as chips got bigger and more complex the ratio of logic to be tested per pin increased dramatically, and the volume of scan test data started causing a significant increase in test time, and required tester memory. This raised the cost of testing. Test compression was developed to help address this problem. When an ATPG tool generates a test for a fault, or a set of faults, only a small percentage of scan cells need to take specific values. The rest of the scan chain is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATPG
ATPG (acronym for both automatic test pattern generation and automatic test pattern generator) is an electronic design automation method or technology used to find an input (or test) sequence that, when applied to a digital circuit, enables automatic test equipment to distinguish between the correct circuit behavior and the faulty circuit behavior caused by defects. The generated patterns are used to test semiconductor devices after manufacture, or to assist with determining the cause of failure (failure analysis). The effectiveness of ATPG is measured by the number of modeled defects, or fault models, detectable and by the number of generated patterns. These metrics generally indicate test quality (higher with more fault detections) and test application time (higher with more patterns). ATPG efficiency is another important consideration that is influenced by the fault model under consideration, the type of circuit under test ( full scan, synchronous sequential, or asynchronous seq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequential Circuit
In automata theory, sequential logic is a type of logic circuit whose output depends on the present value of its input signals and on the sequence of past inputs, the input history. This is in contrast to '' combinational logic'', whose output is a function of only the present input. That is, sequential logic has ''state'' (''memory'') while combinational logic does not. Sequential logic is used to construct finite-state machines, a basic building block in all digital circuitry. Virtually all circuits in practical digital devices are a mixture of combinational and sequential logic. A familiar example of a device with sequential logic is a television set with "channel up" and "channel down" buttons. Pressing the "up" button gives the television an input telling it to switch to the next channel above the one it is currently receiving. If the television is on channel 5, pressing "up" switches it to receive channel 6. However, if the television is on channel 8, pressing "up" switch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flip-flop (electronics)
In electronics, flip-flops and latches are electronic circuit, circuits that have two stable states that can store state information – a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will output its state (often along with its logical complement too). It is the basic storage element in sequential logic. Flip-flops and latches are fundamental building blocks of digital electronics systems used in computers, communications, and many other types of systems. Flip-flops and latches are used as data storage elements to store a single ''bit'' (binary digit) of data; one of its two states represents a "one" and the other represents a "zero". Such data storage can be used for storage of ''state (computer science), state'', and such a circuit is described as sequential logic in electronics. When used in a finite-state machine, the output and next state depend not only on its current input, but also on its current stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
