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Micro-operation
In computer central processing units, micro-operations (also known as micro-ops or μops, historically also as micro-actions) are detailed low-level instructions used in some designs to implement complex machine instructions (sometimes termed macro-instructions in this context). Usually, micro-operations perform basic operations on data stored in one or more processor register, registers, including transferring data between registers or between registers and external bus (computing), buses of the central processing unit (CPU), and performing arithmetic or logical operations on registers. In a typical fetch-decode-execute cycle, each step of a macro-instruction is decomposed during its execution so the CPU determines and steps through a series of micro-operations. The execution of micro-operations is performed under control of the CPU's control unit, which decides on their execution while performing various optimizations such as reordering, fusion and caching. Optimizations V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro-operation Cache
A CPU cache is a hardware cache used by the central processing unit (CPU) of a computer to reduce the average cost (time or energy) to access data from the main memory. A cache is a smaller, faster memory, located closer to a processor core, which stores copies of the data from frequently used main memory locations. Most CPUs have a hierarchy of multiple cache levels (L1, L2, often L3, and rarely even L4), with different instruction-specific and data-specific caches at level 1. The cache memory is typically implemented with static random-access memory (SRAM), in modern CPUs by far the largest part of them by chip area, but SRAM is not always used for all levels (of I- or D-cache), or even any level, sometimes some latter or all levels are implemented with eDRAM. Other types of caches exist (that are not counted towards the "cache size" of the most important caches mentioned above), such as the translation lookaside buffer (TLB) which is part of the memory management unit (MM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcode
In processor design, microcode serves as an intermediary layer situated between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. It consists of a set of hardware-level instructions that implement the higher-level machine code instructions or control internal finite-state machine sequencing in many digital processing components. While microcode is utilized in Intel and AMD general-purpose CPUs in contemporary desktops and laptops, it functions only as a fallback path for scenarios that the faster hardwired control unit is unable to manage. Housed in special high-speed memory, microcode translates machine instructions, state machine data, or other input into sequences of detailed circuit-level operations. It separates the machine instructions from the underlying electronics, thereby enabling greater flexibility in designing and altering instructions. Moreover, it facilitates the construction of complex multi-step inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Instruction Set Computer
A complex instruction set computer (CISC ) is a computer architecture in which single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or are capable of multi-step operations or addressing modes within single instructions. The term was retroactively coined in contrast to reduced instruction set computer (RISC) and has therefore become something of an umbrella term for everything that is not RISC, where the typical differentiating characteristic is that most RISC designs use uniform instruction length for almost all instructions, and employ strictly separate load and store instructions. Examples of CISC architectures include complex mainframe computers to simplistic microcontrollers where memory load and store operations are not separated from arithmetic instructions. Specific instruction set architectures that have been retroactively labeled CISC are System/360 through z/Architecture, the PDP-1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBurst
The NetBurst microarchitecture, called P68 inside Intel, was the successor to the P6 microarchitecture in the x86 family of central processing units (CPUs) made by Intel. The first CPU to use this architecture was the Willamette-core Pentium 4, released on November 20, 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst. In mid-2001, Intel released the ''Foster'' core, which was also based on NetBurst, thus switching the Xeon CPUs to the new architecture as well. Pentium 4-based Celeron CPUs also use the NetBurst architecture. NetBurst was replaced with the Core microarchitecture based on P6, released in July 2006. Technology The NetBurst microarchitecture includes features such as Hyper-threading, Hyper Pipelined Technology, Rapid Execution Engine, Execution Trace Cache, and replay system which all were introduced for the first time in this particular microarchitecture, and some never appeared ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Unit
The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. A CU typically uses a binary decoder to convert coded instructions into timing and control signals that direct the operation of the other units (memory, arithmetic logic unit and input and output devices, etc.). Most computer resources are managed by the CU. It directs the flow of data between the CPU and the other devices. John von Neumann included the control unit as part of the von Neumann architecture. In modern computer designs, the control unit is typically an internal part of the CPU with its overall role and operation unchanged since its introduction. Multicycle control units The simplest computers use a multicycle microarchitecture. These were the earliest designs. They are still popular in the very smallest computers, such as the embedded systems that operate machinery. In a computer, the control unit often steps through the instructio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmetic Logic Unit
In computing, an arithmetic logic unit (ALU) is a Combinational logic, combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. It is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). The inputs to an ALU are the data to be operated on, called operands, and a code indicating the operation to be performed (opcode); the ALU's output is the result of the performed operation. In many designs, the ALU also has status inputs or outputs, or both, which convey information about a previous operation or the current operation, respectively, between the ALU and external status registers. Signals An ALU has a variety of input and output net (electronics), nets, which are the electrical conductors used to convey Digital signal (electroni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferranti Limited
Ferranti International PLC or simply Ferranti was a UK-based electrical engineering and equipment firm that operated for over a century, from 1885 until its bankruptcy in 1993. At its peak, Ferranti was a significant player in power grid systems, defense electronics, and computing, and was once a constituent of the FTSE 100 Index. The company had an extensive presence in the defense sector, manufacturing advanced cockpit displays, radar transmitters, inertial navigation systems, and avionics for military aircraft, including the Tornado fighter jet. It was a pioneer in computer technology, launching the Ferranti Mark 1 in 1951, one of the world's first commercially available computers. Ferranti's global footprint extended beyond the UK, with factories and branch plants in Australia, Canada, Singapore, Germany, and the United States. The company had a strong presence in Edinburgh, with numerous branch-plants as well as an aviation facility. Despite its eventual collapse, som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentium 4
Pentium 4 is a series of single-core central processing unit, CPUs for Desktop computer, desktops, laptops and entry-level Server (computing), servers manufactured by Intel. The processors were shipped from November 20, 2000 until August 8, 2008. All Pentium 4 CPUs are based on the NetBurst microarchitecture, the successor to the P6 (microarchitecture), P6. The Pentium 4 #Willamette, Willamette (180 nm) introduced SSE2, while the #Prescott, Prescott (90 nm) introduced SSE3 and later 64-bit technology. Later versions introduced Hyper-threading, Hyper-Threading Technology (HTT). The first Pentium 4-branded processor to implement x86-64, 64-bit was the Prescott (90 nm) (February 2004), but this feature was not enabled. Intel subsequently began selling 64-bit Pentium 4s using the ''"E0" revision'' of the Prescotts, being sold on the OEM market as the Pentium 4, model F. The E0 revision also adds eXecute Disable (XD) (Intel's name for the NX bit) to Intel 64. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer components such as central processing units (CPUs) and related products for business and consumer markets. It is one of the world's List of largest semiconductor chip manufacturers, largest semiconductor chip manufacturers by revenue, and ranked in the Fortune 500, ''Fortune'' 500 list of the List of largest companies in the United States by revenue, largest United States corporations by revenue for nearly a decade, from 2007 to 2016 Fiscal year, fiscal years, until it was removed from the ranking in 2018. In 2020, it was reinstated and ranked 45th, being the List of Fortune 500 computer software and information companies, 7th-largest technology company in the ranking. It was one of the first companies listed on Nasdaq. Intel supplies List of I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Re-order Buffer
A re-order buffer (ROB) is a hardware unit used in an extension to Tomasulo's algorithm to support out-of-order and speculative instruction execution. The extension forces instructions to be committed in-order. The buffer is a circular buffer (to provide a FIFO instruction ordering queue) implemented as an array/vector (which allows recording of results against instructions as they complete out of order). There are three stages to the Tomasulo algorithm: "Issue", "Execute", "Write Result". In an extension to the algorithm, there is an additional "Commit" stage. During the Commit stage, instruction results are stored in a register or memory. The "Write Result" stage is modified to place results in the re-order buffer. Each instruction is tagged in the reservation station with its index in the ROB for this purpose. The contents of the buffer are used for data dependencies of other instructions scheduled in the buffer. The head of the buffer will be committed once its result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
