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Barrel Processor
A barrel processor is a CPU that switches between threads of execution on every cycle. This CPU design technique is also known as "interleaved" or "fine-grained" temporal multithreading. Unlike simultaneous multithreading in modern superscalar architectures, it generally does not allow execution of multiple instructions in one cycle. Like preemptive multitasking, each thread of execution is assigned its own program counter and other hardware registers (each thread's architectural state). A barrel processor can guarantee that each thread will execute one instruction every ''n'' cycles, unlike a preemptive multitasking machine, that typically runs one thread of execution for tens of millions of cycles, while all other threads wait their turn. A technique called C-slowing can automatically generate a corresponding barrel processor design from a single-tasking processor design. An ''n''-way barrel processor generated this way acts much like ''n'' separate multiprocessing cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Processing Unit
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program. This contrasts with external components such as main memory and I/O circuitry, and specialized processors such as graphics processing units (GPUs). The form, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory), decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers and other co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tera Computer Company
The Tera Computer Company was a manufacturer of high-performance computing software and hardware, founded in 1987 in Washington, D.C. and moved 1988 to Seattle, Washington by James Rottsolk and Burton Smith. The company's first supercomputer product, named MTA, featured interleaved multi-threading, i.e. a barrel processor. It also had no data cache, relying instead on switching between threads for latency tolerance, and used a deeply pipelined memory system to handle many simultaneous requests, with address randomization to avoid memory hot spots. Upon acquiring the Cray Research division of Silicon Graphics in 2000, the company was renamed to Cray Inc. See also * Heterogeneous Element Processor The Heterogeneous Element Processor (HEP) was introduced by Denelcor, Inc. in 1982. The HEP's architect was Burton Smith. The machine was designed to solve fluid dynamics problems for the Ballistic Research Laboratory. A HEP system, as the nam ... References * Software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deadlock
In concurrent computing, deadlock is any situation in which no member of some group of entities can proceed because each waits for another member, including itself, to take action, such as sending a message or, more commonly, releasing a lock. Deadlocks are a common problem in multiprocessing systems, parallel computing, and distributed systems, because in these contexts systems often use software or hardware locks to arbitrate shared resources and implement process synchronization. In an operating system, a deadlock occurs when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process. If a process remains indefinitely unable to change its state because resources requested by it are being used by another process that itself is waiting, then the system is said to be in a deadlock. In a communications system, deadlocks occur mainly due t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazard (computer Architecture)
In the domain of central processing unit (CPU) design, hazards are problems with the instruction pipeline in CPU microarchitectures when the next instruction cannot execute in the following clock cycle, and can potentially lead to incorrect computation results. Three common types of hazards are data hazards, structural hazards, and control hazards (branching hazards). There are several methods used to deal with hazards, including pipeline stalls/pipeline bubbling, operand forwarding, and in the case of out-of-order execution, the scoreboarding method and the Tomasulo algorithm. Background Instructions in a pipelined processor are performed in several stages, so that at any given time several instructions are being processed in the various stages of the pipeline, such as fetch and execute. There are many different instruction pipeline microarchitectures, and instructions may be executed out-of-order. A hazard occurs when two or more of these simultaneous (possibly out of or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Pipeline
In computer engineering, instruction pipelining or ILP is a technique for implementing instruction-level parallelism within a single processor. Pipelining attempts to keep every part of the processor busy with some instruction by dividing incoming instructions into a series of sequential steps (the eponymous "pipeline") performed by different processor units with different parts of instructions processed in parallel. Concept and motivation In a pipelined computer, instructions flow through the central processing unit (CPU) in stages. For example, it might have one stage for each step of the von Neumann cycle: Fetch the instruction, fetch the operands, do the instruction, write the results. A pipelined computer usually has "pipeline registers" after each stage. These store information from the instruction and calculations so that the logic gates of the next stage can do the next step. This arrangement lets the CPU complete an instruction on each clock cycle. It is common for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipeline Stall
In the design of pipelined computer processors, a pipeline stall is a delay in execution of an instruction in order to resolve a hazard. Details In a standard five-stage pipeline, during the decoding stage, the control unit will determine whether the decoded instruction reads from a register to which the currently executed instruction writes. If this condition holds, the control unit will stall the instruction by one clock cycle. It also stalls the instruction in the fetch stage, to prevent the instruction in that stage from being overwritten by the next instruction in the program. In a Von Neumann architecture which uses the program counter (PC) register to determine the current instruction being fetched in the pipeline, to prevent new instructions from being fetched when an instruction in the decoding stage has been stalled, the value in the PC register and the instruction in the fetch stage are preserved to prevent changes. The values are preserved until the instruction c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cache Miss
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A ''cache hit'' occurs when the requested data can be found in a cache, while a ''cache miss'' occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs. To be cost-effective and to enable efficient use of data, caches must be relatively small. Nevertheless, caches have proven themselves in many areas of computing, because typical computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested already, and spatial locality, where d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Padauk Technology
''Pterocarpus'' is a pantropical genus of trees in the family Fabaceae. It belongs to the subfamily Faboideae, and was recently assigned to the informal monophyletic ''Pterocarpus'' clade within the Dalbergieae. Most species of ''Pterocarpus'' yield valuable timber traded as padauk (or padouk); other common names are mukwa or narra. '' P. santalinus'' also yields the most precious red sandalwood in China known as Zitan. The wood from the narra tree ('' P. indicus'') and the Burmese padauk tree ('' P. macrocarpus'') is marketed as amboyna when it has grown in the burl form. The scientific name is Latinized Ancient Greek and means "wing fruit", referring to the unusual shape of the seed pods in this genus. Uses Padauk wood is obtained from several species of ''Pterocarpus''. All padauks are of African or Asian origin. Padauks are valued for their toughness, stability in use, and decorativeness, most having a reddish wood. Most Pterocarpus' woods contain either water- or alcoh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcontroller
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Program memory in the form of ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips. In modern terminology, a microcontroller is similar to, but less sophisticated than, a system on a chip (SoC). An SoC may connect the external microcontroller chips as the motherboard components, but an SoC usually integrates the advanced peripherals like graphics processing unit (GPU) and Wi-Fi interface controller as its internal microcontroller unit circuits. Microcontrollers are use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ubicom
Ubicom was a company which developed communications and media processor (CMP) and software platforms for real-time interactive applications and multimedia content delivery in the digital home. The company provided optimized system-level solutions to OEMs for a wide range of products including wireless routers, access points, VoIP gateways, streaming media devices, print servers and other network devices. Ubicom was a venture-backed, privately held company with corporate headquarters in San Jose, California. History Ubicom was founded as Scenix Semiconductor in 1996. The company operated under that name until 1999. In 2000, Scenix became "Ubicom," a word derived from "ubiquitous communications". * April 1999: Mayfield Fund leads $10 million equity investment in Scenix. * November 2000: Scenix changes its name to Ubicom. * November 2002: Intersil and Ubicom demonstrate world's first 802.11g wireless access point. * March 2006: Ubicom secures $20 million in Series 3 funding, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XCore XS1
XMOS is a fabless semiconductor company that develops audio products and multicore microcontrollers. Company history XMOS was founded in July 2005 by Ali Dixon, James Foster, Noel Hurley, David May, and Hitesh Mehta. It received seed funding from the University of Bristol enterprise fund, and Wyvern seed fund. The name XMOS is a loose reference to Inmos. Some concepts found in XMOS technology (such as channels and threads) are part of the Transputer legacy. In the autumn of 2006, XMOS secured funding from Amadeus Capital Partners, DFJ Esprit, and Foundation Capital. It also has strategic investors Robert Bosch Venture Capital GmbH, Huawei Technologies, and Xilinx Inc. In September 2017, XMOS secured $15M in an investment round lead by Infineon Infineon Technologies AG is a German semiconductor manufacturer founded in 1999, when the semiconductor operations of the former parent company Siemens AG were spun off. Infineon has about 50,280 employees and is one of the ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XMOS
XMOS is a fabless semiconductor company that develops audio products and multicore microcontrollers. Company history XMOS was founded in July 2005 by Ali Dixon, James Foster, Noel Hurley, David May, and Hitesh Mehta. It received seed funding from the University of Bristol enterprise fund, and Wyvern seed fund. The name XMOS is a loose reference to Inmos. Some concepts found in XMOS technology (such as channels and threads) are part of the Transputer legacy. In the autumn of 2006, XMOS secured funding from Amadeus Capital Partners, DFJ Esprit, and Foundation Capital. It also has strategic investors Robert Bosch Venture Capital GmbH, Huawei Technologies, and Xilinx Inc. In September 2017, XMOS secured $15M in an investment round lead by Infineon Infineon Technologies AG is a German semiconductor manufacturer founded in 1999, when the semiconductor operations of the former parent company Siemens AG were spun off. Infineon has about 50,280 employees and is one of the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
