Register file - Knowledge

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used in thumb mode). Any GPRs can propagate and store multiple instructions independently in smaller code size that is small enough to be able to fit in one register and its architectural register act as a table and shared with all decoder/instructions with simple bank switching between decoders. The major difference between ARM and other designs is that ARM allows to run on the same general-purpose register with quick bank switching without requiring additional register file in superscalar. Despite x86 sharing the same mechanism with ARM that its GPRs can store any data individually, x86 will confront data dependency if more than three non-related instructions are stored, as its GPRs per file are too small (eight in 32 bit mode and 16 in 64 bit, compared to ARM's 13 in 32 bit and 31 in 64 bit) for data, and it is impossible to have superscalar without multiple register files to feed to its decoder (x86 code is big and complex compared to ARM). Because most x86's front-ends have become much larger and much more power hungry than the ARM processor in order to be competitive (example: Pentium M & Core 2 Duo, Bay Trail). Some third-party x86 equivalent processors even became noncompetitive with ARM due to having no dedicated register-file architecture. Particularly for AMD, Cyrix and VIA that cannot bring any reasonable performance without register renaming and out of order execution, which leave only Intel Atom to be the only in-order x86 processor core in the mobile competition. This was until the x86 Nehalem processor merged both of its integer and floating point register into one single file, and the introduction of a large physical register table and enhanced allocator table in its front-end before renaming in its out-of-order internal core.

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floating-point). This was done in order to solve the register bottleneck that existed in the x86 architecture after micro-operation fusion is introduced, but it is still have 8 entries 32 bit architectural registers for total 32 bytes in capacity per file (segment register and instruction pointer remain within the file, though they are inaccessible by program) as speculative file. The second file is served as a scaled shadow register file, which without context switch the scaled file cannot store some instruction independently. Some instruction from SSE2/SSE3/SSSE3 require this feature for integer operation, for example instruction like PSHUFB, PMADDUBSW, PHSUBW, PHSUBD, PHSUBSW, PHADDW, PHADDD, PHADDSW would require loading EAX/EBX/ECX/EDX from both register files, though it was uncommon for an x86 processor to make use of another register file with the same instruction. Most of time, the second file is served as a scale retired file. The Pentium M architecture still has one dual-ported floating-point register file (8 entries MM/XMM) shared with three decoders, and the FP register file does not have a shadow register file along with it, as its shadow-register-file architecture did not including floating-point functions. In processors after P6, the architectural register files are external and located in the processor's backend after the retired file, as opposed to the internal register file located in the inner core for register renaming/reorder buffer. However, in Core 2 it is now housed within a unit called the "register alias table" (RAT), located with instruction allocator but have same size of register size as retirement.

560:, all register files do not require additional cycle to propagate the data, register files like architectural and floating point are located between code buffer and decoders, called "retire buffer", Reorder buffer and OoOE and connected within the ring bus (16 bytes). The register file itself still remains one x86 register file and one x87 stack and both serve as retirement storing. Its x86 register file was enlarged to dual-ported to increase bandwidth for result storage. Registers like debug/condition code/control/unnamed/flag were stripped from the main register file and placed into individual files between the micro-op ROM and instruction sequencer. Only inaccessible registers like the segment register are now separated from the general-purpose register file (except the instruction pointer); they are now located between the scheduler and instruction allocator, in order to facilitate register renaming and out-of-order execution. The x87 stack was later merged with the floating-point register file after a 128-bit XMM register debuted in Pentium III, but the XMM register file is still located separately from x86 integer register files. 656:. Like early AMD designs, most of the x86 manufacturers like Cyrix, VIA, DM&P, and SIS used the same mechanism as well, resulting in a lack of integer performance without register renaming for their in-order CPU. Companies like Cyrix and AMD had to increase cache size in hope to reduce the bottleneck. AMD's SSE integer operation work in a different way than Core 2 and Pentium 4; it uses its separate renaming integer register to load the value directly before the decode stage. Though theoretically it will only need a shorter pipeline than Intel's SSE implementation, but generally the cost of branch prediction are much greater and higher missing rate than Intel, and it would have to take at least two cycles for its SSE instruction to be executed regardless of instruction wide, as early AMDs implementations could not execute both FP and Int in an SSE instruction set like Intel's implementation did. 496:(EV6), for instance, was the first large micro-architecture to implement a "Shadow Register File Architecture". It had two copies of the integer register file and two copies of the floating point register located in its front end (future and scaled file, each containing 2 read and 2 write ports), and took an extra cycle to propagate data between the two during a context switch. The issuing logic attempted to reduce the number of operations forwarding data between the two and greatly improved its integer performance, and helped reduce the impact of the limited number of general-purpose registers in superscalar architectures with speculative execution. This design was later adapted by 594:

eight-entries 64 bit shadow based register and an eight-entries 64 bit unnamed register that are now separated from main GPRs unlike the original P5 design and located after the execution unit, and the file of these registers is single-ported and not expose to instruction like scaled shadow register file found on Core/Core2 (shadow register file are made of architectural registers and Bonnell did not due to not have "Shadow Register File Architecture"), however the file can be use for renaming purpose due to lack of out of order execution found on Bonnell architecture. It also had one copy of XMM floating point register file per thread. The difference from

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one instruction pointer as they are unable to be access in the file by any code/instruction) in total file size and expanded to 16 entries in x64 for total 128 bytes size per file. From Pentium M as its pipeline port and decoder increased, but they're located with allocator table instead of code buffer. Its FP XMM register file are also increase to quad-ported (2 read/2 write), register still remain 8 entries in 32 bit and extended to 16 entries in x64 mode and number still remain 1 as its shadow-register-file architecture is not including floating point/SSE functions.

705:, in which the 5-bit architectural names of the registers actually point into a window on a much larger register file, with hundreds of entries. Implementing multiported register files with hundreds of entries requires a large area. The register window slides by 16 registers when moved, so that each architectural register name can refer to only a small number of registers in the larger array, e.g. architectural register r20 can only refer to physical registers #20, #36, #52, #68, #84, #100, #116, if there are just seven windows in the physical file. 638:'s early design like K6 do not have a register file like Intel and do not support "Shadow Register File Architecture" as its lack of context switch and bypass inverter that are necessary require for a register file to function appropriately. Instead they use a separate GPRs that directly link to a rename register table for its OoOE CPU with a dedicated integer decoder and floating decoder. The mechanism is similar to Intel's pre-Pentium processor line. For example, the 351: 25: 417: 689:

benefits from replication and subsetting the read ports. At the limit, this technique would place a stack of 1-write, 2-read regfiles at the inputs to each functional unit. Since regfiles with a small number of ports are often dominated by transistor area, it is best not to push this technique to this limit, but it is useful all the same.

544:, a typical Pentium-compatible x86 processor is integrated with one copy of a single-port architectural register file containing 6 general-purpose registers, 4 control registers, 8 debug registers (two reserved), 1 stack pointer register, 1 stack base register, 1 instruction pointer, 1 flags register, and 6 segment registers. 576:

and later processors, both integer and floating point registers are now incorporated into a unified octa-ported (six read and two write) general-purpose register file (8 + 8 in 32-bit and 16 + 16 in x64 per file), while the register file extended to 2 with enhanced "Shadow Register File Architecture"

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increased the inner ring bus to 24 bytes (allow more than 3 instructions to be decoded) and extended its register file from dual-ported (one read/one write) to quad-ported (two read/two write), register still remain 8 entries in 32 bit and 32 bytes (not including 6 segment register and

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uses multiple register files as well. The R8000 floating-point unit had two copies of the floating-point register file, each with four write and four read ports, and wrote both copies at the same time with a context switch. However, it did not support integer operations, and the integer register file

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uses a "Shadow Register File Architecture" as well for its high-end line. It has up to 4 copies of integer register files (future, retired, scaled, and scratched, each containing 7 read 4 write port) and 2 copies of the floating point register file. However, unlike Alpha and x86, they are located in

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Most register files make no special provisions to prevent multiple write ports from writing to the same entry simultaneously. Instead, the instruction scheduling hardware ensures that only one instruction in any particular cycle writes a particular entry. If multiple instructions targeting the same

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microarchitecture), on the other hand, does not have a register file for its decoder, as its x86 GPRs didn't exist within its structure, due to the introduction of a physical unified renaming register file (similar to Sandy Bridge, but slightly different due to the inability of Pentium 4 to use the

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ARM processors have both banked and unbanked registers. While all modes always share the same physical registers for the first eight general-purpose registers, R0 to R7, the physical register which the banked registers, R8 to R14, point to depends on the operating mode the processor is in. Notably,

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There is one decoder per read or write port. If the array has four read and two write ports, for example, it has 6 word lines per bit cell in the array, and six AND gates per row in the decoder. Note that the decoder has to be pitch matched to the array, which forces those AND gates to be wide and

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register renaming mapping file, which stores a 6-bit virtual register number for each of the physical registers. In the renaming file, the renaming state is checkpointed whenever a branch is taken, so that when a branch is detected to be mispredicted, the old renaming state can be recovered in a

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To save area, some SPARC implementations implement a 32-entry register file, in which each cell has seven "bits". Only one is read and writeable through the external ports, but the contents of the bits can be rotated. A rotation accomplishes in a single cycle a movement of the register window.

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processor on the other hand does not integrate multiple register files to load/fetch instructions. ARM GPRs have no special purpose to the instruction set (the ARM ISA does not require accumulator, index, and stack/base points. Registers do not have an accumulator and base/stack point can only be

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processor has four int (one eight-entries temporary scratched register file + one eight-entries future register file + one eight-entries fetched register file + an eight-entries unnamed register file) and two FP rename register files (two eight-entries x87 ST file one goes fadd and one goes fmov)

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Later P6 implementations (Pentium M, Yonah) introduced a "Shadow Register File Architecture" that expanded to 2 copies of dual-ported integer architectural register files and consist with context switch (between future and retired file and scaled file using the same trick used between integer and

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IBM uses the same mechanism as many major microprocessors, deeply merging the register file with the decoder, but its register files work independently of the decoder side and do not involve context switching, which is different from Alpha and x86. Most of its register files do not only serve its

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included "shadow register" in its front end, it's scaled up to 40 entries unified register file for in order integer operation before decoded, the register file contain 8 entries scratch register + 16 future GPRs register file + 16 unnamed GPRs register file. In later AMD designs it abandons the

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that it serves. Pitch matching avoids having many busses passing over the datapath turn corners, which would use a lot of area. But since every unit must have the same bit pitch, every unit in the datapath ends up with the bit pitch forced by the widest unit, which can waste area in the other

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also each have only one general-purpose integer register file, but the Larrabee has up to 16 XMM register files (8 entries per file), and the Xeon Phi has up to 128 AVX-512 register files, each containing 32 512-bit ZMM registers for vector instruction storage, which can be as big as L2 cache.

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can arrange for each functional unit to write to a subset of the physical register file. This arrangement can eliminate the need for multiple write ports per bit cell, for large savings in area. The resulting register file, effectively a stack of register files with single write ports, then

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processors use context switching and fast interrupts for switching between instruction, decoder, GPRs and register files, if there is more than one, before the instruction is issued, but this only exists on processors that support superscalar execution. However, context switching is a totally

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The crossed inverters take some finite time to settle after a write operation, during which a read operation will either take longer or return garbage. It is common to have bypass multiplexers that bypass written data to the read ports when a simultaneous read and write to the same entry is

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Register files have one word line per entry per port, one bit line per bit of width per read port, and two bit lines per bit of width per write port. Each bit cell also has a Vdd and Vss. Therefore, the wire pitch area increases as the square of the number of ports, and the transistor area

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line was the modern simplified revision of P5. It includes single copies of register file share with thread and decoder. The register file is a dual-port design, 8/16 entries GPRS, 8/16 entries debug register and 8/16 entries condition code are integrated in the same file. However it has an

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register before naming) for attempting to replace the architectural register file and skip the x86 decoding scheme. Instead it uses SSE for integer execution and storage before the ALU and after result, SSE2/SSE3/SSSE3 use the same mechanism as well for its integer operation.

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Area can sometimes be saved on machines with multiple units in a datapath by having two datapaths side-by-side, each of which has smaller bit pitch than a single datapath would have. This case usually forces multiple copies of a register file, one for each datapath.

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register were virtually simulated from x87 stack and require x86 register to supplying MMX instruction and aliases to exist stack. On P6, the instruction independently can be stored and executed in parallel in early pipeline stages before decoding into

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and onward replaced shadow register table and architectural registers with much large and yet more advance physical register file before decoding to the reorder buffer. Randered that Sandy Bridge and onward no longer carry an architectural register.

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Read bit lines often swing only a fraction of the way to Vdd or Vss. A sense amplifier converts this small-swing signal into a full logic level. Small swing signals are faster because the bit line has little drive but a great deal of parasitic

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processor line, a typical pre-486 CPU did not have an individual register file, as all general purpose registers worked directly with the decoder, and the x87 push stack was located within the floating-point unit itself. Starting with the

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the backend as a retire unit right after its out-of-order unit and renaming register files. The shadow registers do not load instructions during instruction fetching and decoding stages and a context switch is unnecessary in this design.

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In principle, any operation that could be done with a 64-bit-wide register file with many read and write ports could be done with a single 8-bit-wide register file with a single read port and a single write port. However, the

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is Bonnell do not have a unified register file and has no dedicated register file for its hyper threading. Instead, Bonnell uses a separate rename register for its thread despite it is not out of order. Similar to Bonnell,

225:, which convert low-swing read bitlines into full-swing logic levels, are usually at the bottom (by convention). Larger register files are then sometimes constructed by tiling mirrored and rotated simple arrays. 258:. Occasionally it is slightly wider in order to attach "extra" bits to each register, such as the poison bit. If the width of the data word is different than the width of an address—or in some cases, such as the 229:

increases linearly. At some point, it may be smaller and/or faster to have multiple redundant register files, with smaller numbers of read ports, rather than a single register file with all the read ports. The

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of wide register files with many ports allows them to run much faster and thus, they can do operations in a single cycle that would take many cycles with fewer ports or a narrower bit width or both.

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If Vdd is a horizontal line, it can be switched off, by yet another decoder, if any of the write ports are writing that line during that cycle. This optimization increases the speed of the write.

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units. Register files, because they have two wires per bit per write port, and because all the bit lines must contact the silicon at every bit cell, can often set the pitch of a datapath.

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Write bit lines may be braided, so that they couple equally to the nearby read bitlines. Because write bitlines are full swing, they can cause significant disturbances on read bitlines.

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with multiple ports. Such RAMs are distinguished by having dedicated read and write ports, whereas ordinary multiported SRAMs will usually read and write through the same ports.

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unit, for example, had a 9 read 4 write port 32 entry 64-bit register file implemented in a 0.7 μm process, which could be seen when looking at the chip from arm's length.

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Two popular approaches to dividing registers into multiple register files are the distributed register file configuration and the partitioned register file configuration.

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of a CPU will almost always define a set of registers which are used to stage data between memory and the functional units on the chip. The register file is part of the

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commanded. These bypass multiplexers are often part of a larger bypass network that forwards results which have not yet been committed between functional units.

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A typical register file – "triple-ported", able to read from 2 registers and write to 1 register simultaneously – is made of bit cells like this one.

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The usual layout convention is that a simple array is read out vertically. That is, a single word line, which runs horizontally, causes a row of

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that only allows one register file to load/fetch one operand at the time; it would require multiple register files to achieve superscale. The

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has up to 8 instruction decoders, but up to 32 register files of 32 general purpose registers each (4 read and 4 write ports) to facilitate

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Because most of the wires accomplishing the state movement are local, tremendous bandwidth is possible with little power.

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still remained as such. Later, shadow register files were abandoned in newer designs in favor of the embedded market.

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is the method of using a single name to access multiple different physical registers depending on the operating mode.

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correspond one-for-one to the entries in a physical register file (PRF) within the CPU. More complicated CPUs use

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that directly link with its x86 EAX for integer renaming and XMM0 register for floating point renaming, but later

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shadow register design and favored to K6 architecture with individual GPRs direct link design. Like

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There are some other of Intel's x86 lines that don't have a register file in their internal design,

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Data is written by shorting one side or the other to ground through a two-NMOS stack.

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use bits in the program status word to select the currently active register bank.

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The width in bits of the register file is usually the number of bits in the

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and visible to the programmer, as opposed to the concept of transparent

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and each thread uses independent register files for its decoder. Later

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Techniques that reduce the energy used by register files are useful in

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So: read ports take one transistor per bit cell, write ports take four.

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Read bit lines are often precharged to something between Vdd and Vss.

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different mechanism to ARM's register bank within the registers.

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The decoder is often broken into pre-decoder and decoder proper.

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dedicated decoder, but up to the thread level. For example,

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Wikibooks: Microprocessor Design/Register File#Register Bank

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The decoder is a series of AND gates that drive word lines.

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and renaming in out-of-order execution. Beginning with

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to put their data on bit lines, which run vertically.

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Sharing lines between cells, for example, Vdd and Vss.

49:. Unsourced material may be challenged and removed. 480:The register file is usually pitch-matched to the 302:Data is read out by NMOS transistor to a bit line. 547:One copy of 8 x87 FP push down stack by default, 2773: 844: 1849:Computer performance by orders of magnitude 504:and some of the later x86 implementations. 379:. Unsourced material may be challenged and 858: 851: 837: 171: 805:by Aneesh Aggarwal and M. Franklin. 2003. 785: 783: 619:and many embedded processors that aren't 460:Learn how and when to remove this message 399:Learn how and when to remove this message 109:Learn how and when to remove this message 286: 16:Working storage in a computer processor 2774: 780: 832: 299:State is stored in pair of inverters. 1820:Floating-point operations per second 679: 410: 377:adding citations to reliable sources 344: 340: 47:adding citations to reliable sources 18: 763:"ARM Architecture Reference Manual" 712:This same technique is used in the 692: 572:In later x86 implementations, like 13: 209: 14: 2803: 812: 312:Many optimizations are possible: 295:The basic scheme for a bit cell: 205: 2746:Semiconductor device fabrication 415: 349: 23: 2721:History of general-purpose CPUs 948:Nondeterministic Turing machine 34:needs additional citations for 901:Deterministic finite automaton 796: 755: 743: 1: 1692:Simultaneous and heterogenous 736: 2376:Integrated memory controller 2358:Translation lookaside buffer 1557:Memory dependence prediction 1000:Random-access stored program 953:Probabilistic Turing machine 135:instruction set architecture 7: 1832:Synaptic updates per second 793:. 2001. p. 169. p. 171-173. 724: 530:simultaneous multithreading 435:. The specific problem is: 10: 2808: 2236:Heterogeneous architecture 1158:Orthogonal instruction set 928:Alternating Turing machine 916:Quantum cellular automaton 265: 200:8051-compatible processors 2726:Microprocessor chronology 2713: 2689:Dynamic frequency scaling 2662: 2598: 2536: 2490: 2442: 2397: 2317: 2244: 2213: 2118: 2039: 2003: 1957: 1857: 1844:Cache performance metrics 1783: 1717: 1667: 1578: 1569: 1542: 1497: 1464: 1436: 1427: 1247: 1150: 1139: 1010: 866: 577:in favorite of executing 145:. In simpler CPUs, these 2741:Hardware security module 2084:Digital signal processor 2061:Graphics processing unit 1873:Graphics processing unit 768:. ARM Limited. July 2005 684:Processors that perform 282: 2694:Dynamic voltage scaling 2477:Memory address register 2371:Branch target predictor 2335:Address generation unit 2078:Physics processing unit 1867:Central processing unit 1826:Transactions per second 1814:Instructions per second 1737:Array processing (SIMT) 881:Stored-program computer 172:Register-bank switching 147:architectural registers 131:central processing unit 2500:Hardwired control unit 2382:Memory management unit 2347:Memory management unit 2096:Secure cryptoprocessor 2090:Tensor Processing Unit 2072:Vision processing unit 1806:Cycles per instruction 1800:Instructions per cycle 1747:Associative processing 1438:Instruction pipelining 860:Processor technologies 292: 214: 182:Fast Interrupt Request 2782:Computer architecture 2583:Sum-addressed decoder 2329:Arithmetic logic unit 1456:Classic RISC pipeline 1410:Epiphany architecture 1257:Motorola 68000 series 731:Sum-addressed decoder 334:low-power electronics 290: 249:bit-level parallelism 213: 2704:Performance per watt 2282:replacement policies 1948:Package on a package 1838:Performance per watt 1742:Pipelined processing 1512:Tomasulo's algorithm 1317:Clipper architecture 1173:Application-specific 886:Finite-state machine 717:single cycle. (See 442:improve this section 431:to meet Knowledge's 373:improve this section 43:improve this article 2787:Digital electronics 2736:Digital electronics 2389:Instruction decoder 2341:Floating-point unit 1995:Soft microprocessor 1942:System in a package 1517:Reservation station 1047:Transport-triggered 256:processor word size 127:processor registers 2608:Integrated circuit 2452:Processor register 2106:Baseband processor 1451:Operand forwarding 911:Cellular automaton 293: 215: 158:integrated circuit 2792:Digital registers 2769: 2768: 2658: 2657: 2277:Instruction cache 2267:Scratchpad memory 2114: 2113: 2101:Network processor 2030:Network on a chip 1985:Ultra-low-voltage 1936:Multi-chip module 1779: 1778: 1565: 1564: 1552:Branch prediction 1529:Register renaming 1423: 1422: 1405:VISC architecture 1227:Quantum computing 1222:VISC architecture 1104:Secondary storage 1020:Microarchitecture 980:Register machines 719:Register renaming 686:register renaming 680:Register renaming 470: 469: 462: 433:quality standards 424:This section may 409: 408: 401: 341:Microarchitecture 151:register renaming 119: 118: 111: 93: 2799: 2731:Processor design 2623:Power management 2505:Instruction unit 2366:Branch predictor 2315: 2314: 2013:System on a chip 1955: 1954: 1795:Transistor count 1719:Flynn's taxonomy 1576: 1575: 1434: 1433: 1237:Addressing modes 1148: 1147: 1094:Memory hierarchy 958:Hypercomputation 876:Abstract machine 853: 846: 839: 830: 829: 806: 800: 794: 787: 778: 777: 775: 773: 767: 759: 753: 747: 703:register windows 693:Register windows 554:micro-operations 465: 458: 454: 451: 445: 419: 418: 411: 404: 397: 393: 390: 384: 353: 345: 166:Register banking 114: 107: 103: 100: 94: 92: 51: 27: 19: 2807: 2806: 2802: 2801: 2800: 2798: 2797: 2796: 2772: 2771: 2770: 2765: 2751:Tick–tock model 2709: 2665: 2654: 2594: 2578:Address decoder 2532: 2486: 2482:Program counter 2457:Status register 2438: 2393: 2353:Load–store unit 2320: 2313: 2240: 2209: 2110: 2067:Image processor 2042: 2035: 2005: 1999: 1975:Microcontroller 1965:Embedded system 1953: 1853: 1786: 1775: 1713: 1663: 1561: 1538: 1522:Re-order buffer 1493: 1474:Data dependency 1460: 1419: 1249: 1243: 1142: 1141:Instruction set 1135: 1121:Multiprocessing 1089:Cache hierarchy 1082:Register/memory 1006: 906:Queue automaton 862: 857: 815: 810: 809: 801: 797: 789:Johan Janssen. 788: 781: 771: 769: 765: 761: 760: 756: 748: 744: 739: 727: 695: 682: 579:hyper threading 466: 455: 449: 446: 439: 420: 416: 405: 394: 388: 385: 370: 354: 343: 285: 268: 208: 174: 125:is an array of 115: 104: 98: 95: 58:"Register file" 52: 50: 40: 28: 17: 12: 11: 5: 2805: 2795: 2794: 2789: 2784: 2767: 2766: 2764: 2763: 2758: 2756:Pin grid array 2753: 2748: 2743: 2738: 2733: 2728: 2723: 2717: 2715: 2711: 2710: 2708: 2707: 2701: 2696: 2691: 2686: 2681: 2676: 2670: 2668: 2660: 2659: 2656: 2655: 2653: 2652: 2647: 2642: 2637: 2632: 2627: 2626: 2625: 2620: 2615: 2604: 2602: 2596: 2595: 2593: 2592: 2590:Barrel shifter 2587: 2586: 2585: 2580: 2573:Binary decoder 2570: 2569: 2568: 2558: 2553: 2548: 2542: 2540: 2534: 2533: 2531: 2530: 2525: 2517: 2512: 2507: 2502: 2496: 2494: 2488: 2487: 2485: 2484: 2479: 2474: 2469: 2464: 2462:Stack register 2459: 2454: 2448: 2446: 2440: 2439: 2437: 2436: 2435: 2434: 2429: 2419: 2414: 2409: 2403: 2401: 2395: 2394: 2392: 2391: 2386: 2385: 2384: 2373: 2368: 2363: 2362: 2361: 2355: 2344: 2338: 2332: 2325: 2323: 2312: 2311: 2306: 2301: 2296: 2291: 2290: 2289: 2284: 2279: 2274: 2269: 2264: 2254: 2248: 2246: 2242: 2241: 2239: 2238: 2233: 2228: 2223: 2217: 2215: 2211: 2210: 2208: 2207: 2206: 2205: 2195: 2190: 2185: 2180: 2175: 2170: 2165: 2160: 2155: 2150: 2145: 2140: 2135: 2130: 2124: 2122: 2116: 2115: 2112: 2111: 2109: 2108: 2103: 2098: 2093: 2087: 2081: 2075: 2069: 2064: 2058: 2056:AI accelerator 2053: 2047: 2045: 2037: 2036: 2034: 2033: 2027: 2022: 2019:Multiprocessor 2016: 2009: 2007: 2001: 2000: 1998: 1997: 1992: 1987: 1982: 1977: 1972: 1970:Microprocessor 1967: 1961: 1959: 1958:By application 1952: 1951: 1945: 1939: 1933: 1928: 1923: 1918: 1913: 1908: 1903: 1901:Tile processor 1898: 1893: 1888: 1883: 1882: 1881: 1870: 1863: 1861: 1855: 1854: 1852: 1851: 1846: 1841: 1835: 1829: 1823: 1817: 1811: 1810: 1809: 1797: 1791: 1789: 1781: 1780: 1777: 1776: 1774: 1773: 1772: 1771: 1761: 1756: 1755: 1754: 1749: 1744: 1739: 1729: 1723: 1721: 1715: 1714: 1712: 1711: 1706: 1701: 1696: 1695: 1694: 1689: 1687:Hyperthreading 1679: 1673: 1671: 1669:Multithreading 1665: 1664: 1662: 1661: 1656: 1651: 1650: 1649: 1639: 1638: 1637: 1632: 1622: 1621: 1620: 1615: 1605: 1600: 1599: 1598: 1593: 1582: 1580: 1573: 1567: 1566: 1563: 1562: 1560: 1559: 1554: 1548: 1546: 1540: 1539: 1537: 1536: 1531: 1526: 1525: 1524: 1519: 1509: 1503: 1501: 1495: 1494: 1492: 1491: 1486: 1481: 1476: 1470: 1468: 1462: 1461: 1459: 1458: 1453: 1448: 1446:Pipeline stall 1442: 1440: 1431: 1425: 1424: 1421: 1420: 1418: 1417: 1412: 1407: 1402: 1399: 1398: 1397: 1395:z/Architecture 1392: 1387: 1382: 1374: 1369: 1364: 1359: 1354: 1349: 1344: 1339: 1334: 1329: 1324: 1319: 1314: 1313: 1312: 1307: 1302: 1294: 1289: 1284: 1279: 1274: 1269: 1264: 1259: 1253: 1251: 1245: 1244: 1242: 1241: 1240: 1239: 1229: 1224: 1219: 1214: 1209: 1204: 1199: 1198: 1197: 1187: 1186: 1185: 1175: 1170: 1165: 1160: 1154: 1152: 1145: 1137: 1136: 1134: 1133: 1128: 1123: 1118: 1113: 1108: 1107: 1106: 1101: 1099:Virtual memory 1091: 1086: 1085: 1084: 1079: 1074: 1069: 1059: 1054: 1049: 1044: 1039: 1038: 1037: 1027: 1022: 1016: 1014: 1008: 1007: 1005: 1004: 1003: 1002: 997: 992: 987: 977: 972: 967: 966: 965: 960: 955: 950: 945: 940: 935: 930: 923:Turing machine 920: 919: 918: 913: 908: 903: 898: 893: 883: 878: 872: 870: 864: 863: 856: 855: 848: 841: 833: 827: 826: 814: 813:External links 811: 808: 807: 795: 779: 754: 741: 740: 738: 735: 734: 733: 726: 723: 694: 691: 681: 678: 627:(based on the 468: 467: 423: 421: 414: 407: 406: 389:September 2015 357: 355: 348: 342: 339: 338: 337: 330: 327: 324: 320: 317: 310: 309: 306: 303: 300: 284: 281: 280: 279: 275: 272: 267: 264: 207: 206:Implementation 204: 198:and the later 173: 170: 117: 116: 31: 29: 22: 15: 9: 6: 4: 3: 2: 2804: 2793: 2790: 2788: 2785: 2783: 2780: 2779: 2777: 2762: 2759: 2757: 2754: 2752: 2749: 2747: 2744: 2742: 2739: 2737: 2734: 2732: 2729: 2727: 2724: 2722: 2719: 2718: 2716: 2712: 2705: 2702: 2700: 2697: 2695: 2692: 2690: 2687: 2685: 2682: 2680: 2677: 2675: 2672: 2671: 2669: 2667: 2661: 2651: 2648: 2646: 2643: 2641: 2638: 2636: 2633: 2631: 2628: 2624: 2621: 2619: 2616: 2614: 2611: 2610: 2609: 2606: 2605: 2603: 2601: 2597: 2591: 2588: 2584: 2581: 2579: 2576: 2575: 2574: 2571: 2567: 2564: 2563: 2562: 2559: 2557: 2554: 2552: 2551:Demultiplexer 2549: 2547: 2544: 2543: 2541: 2539: 2535: 2529: 2526: 2524: 2521: 2518: 2516: 2513: 2511: 2508: 2506: 2503: 2501: 2498: 2497: 2495: 2493: 2489: 2483: 2480: 2478: 2475: 2473: 2472:Memory buffer 2470: 2468: 2467:Register file 2465: 2463: 2460: 2458: 2455: 2453: 2450: 2449: 2447: 2445: 2441: 2433: 2430: 2428: 2425: 2424: 2423: 2420: 2418: 2415: 2413: 2410: 2408: 2407:Combinational 2405: 2404: 2402: 2400: 2396: 2390: 2387: 2383: 2380: 2379: 2377: 2374: 2372: 2369: 2367: 2364: 2359: 2356: 2354: 2351: 2350: 2348: 2345: 2342: 2339: 2336: 2333: 2330: 2327: 2326: 2324: 2322: 2316: 2310: 2307: 2305: 2302: 2300: 2297: 2295: 2292: 2288: 2285: 2283: 2280: 2278: 2275: 2273: 2270: 2268: 2265: 2263: 2260: 2259: 2258: 2255: 2253: 2250: 2249: 2247: 2243: 2237: 2234: 2232: 2229: 2227: 2224: 2222: 2219: 2218: 2216: 2212: 2204: 2201: 2200: 2199: 2196: 2194: 2191: 2189: 2186: 2184: 2181: 2179: 2176: 2174: 2171: 2169: 2166: 2164: 2161: 2159: 2156: 2154: 2151: 2149: 2146: 2144: 2141: 2139: 2136: 2134: 2131: 2129: 2126: 2125: 2123: 2121: 2117: 2107: 2104: 2102: 2099: 2097: 2094: 2091: 2088: 2085: 2082: 2079: 2076: 2073: 2070: 2068: 2065: 2062: 2059: 2057: 2054: 2052: 2049: 2048: 2046: 2044: 2038: 2031: 2028: 2026: 2023: 2020: 2017: 2014: 2011: 2010: 2008: 2002: 1996: 1993: 1991: 1988: 1986: 1983: 1981: 1978: 1976: 1973: 1971: 1968: 1966: 1963: 1962: 1960: 1956: 1949: 1946: 1943: 1940: 1937: 1934: 1932: 1929: 1927: 1924: 1922: 1919: 1917: 1914: 1912: 1909: 1907: 1904: 1902: 1899: 1897: 1894: 1892: 1889: 1887: 1884: 1880: 1877: 1876: 1874: 1871: 1868: 1865: 1864: 1862: 1860: 1856: 1850: 1847: 1845: 1842: 1839: 1836: 1833: 1830: 1827: 1824: 1821: 1818: 1815: 1812: 1807: 1804: 1803: 1801: 1798: 1796: 1793: 1792: 1790: 1788: 1782: 1770: 1767: 1766: 1765: 1762: 1760: 1757: 1753: 1750: 1748: 1745: 1743: 1740: 1738: 1735: 1734: 1733: 1730: 1728: 1725: 1724: 1722: 1720: 1716: 1710: 1707: 1705: 1702: 1700: 1697: 1693: 1690: 1688: 1685: 1684: 1683: 1680: 1678: 1675: 1674: 1672: 1670: 1666: 1660: 1657: 1655: 1652: 1648: 1645: 1644: 1643: 1640: 1636: 1633: 1631: 1628: 1627: 1626: 1623: 1619: 1616: 1614: 1611: 1610: 1609: 1606: 1604: 1601: 1597: 1594: 1592: 1589: 1588: 1587: 1584: 1583: 1581: 1577: 1574: 1572: 1568: 1558: 1555: 1553: 1550: 1549: 1547: 1545: 1541: 1535: 1532: 1530: 1527: 1523: 1520: 1518: 1515: 1514: 1513: 1510: 1508: 1507:Scoreboarding 1505: 1504: 1502: 1500: 1496: 1490: 1489:False sharing 1487: 1485: 1482: 1480: 1477: 1475: 1472: 1471: 1469: 1467: 1463: 1457: 1454: 1452: 1449: 1447: 1444: 1443: 1441: 1439: 1435: 1432: 1430: 1426: 1416: 1413: 1411: 1408: 1406: 1403: 1400: 1396: 1393: 1391: 1388: 1386: 1383: 1381: 1378: 1377: 1375: 1373: 1370: 1368: 1365: 1363: 1360: 1358: 1355: 1353: 1350: 1348: 1345: 1343: 1340: 1338: 1335: 1333: 1330: 1328: 1325: 1323: 1320: 1318: 1315: 1311: 1308: 1306: 1303: 1301: 1298: 1297: 1295: 1293: 1290: 1288: 1285: 1283: 1282:Stanford MIPS 1280: 1278: 1275: 1273: 1270: 1268: 1265: 1263: 1260: 1258: 1255: 1254: 1252: 1246: 1238: 1235: 1234: 1233: 1230: 1228: 1225: 1223: 1220: 1218: 1215: 1213: 1210: 1208: 1205: 1203: 1200: 1196: 1193: 1192: 1191: 1188: 1184: 1181: 1180: 1179: 1176: 1174: 1171: 1169: 1166: 1164: 1161: 1159: 1156: 1155: 1153: 1149: 1146: 1144: 1143:architectures 1138: 1132: 1129: 1127: 1124: 1122: 1119: 1117: 1114: 1112: 1111:Heterogeneous 1109: 1105: 1102: 1100: 1097: 1096: 1095: 1092: 1090: 1087: 1083: 1080: 1078: 1075: 1073: 1070: 1068: 1065: 1064: 1063: 1062:Memory access 1060: 1058: 1055: 1053: 1050: 1048: 1045: 1043: 1040: 1036: 1033: 1032: 1031: 1028: 1026: 1023: 1021: 1018: 1017: 1015: 1013: 1009: 1001: 998: 996: 995:Random-access 993: 991: 988: 986: 983: 982: 981: 978: 976: 975:Stack machine 973: 971: 968: 964: 961: 959: 956: 954: 951: 949: 946: 944: 941: 939: 936: 934: 931: 929: 926: 925: 924: 921: 917: 914: 912: 909: 907: 904: 902: 899: 897: 894: 892: 891:with datapath 889: 888: 887: 884: 882: 879: 877: 874: 873: 871: 869: 865: 861: 854: 849: 847: 842: 840: 835: 834: 831: 825:, Chow - 1995 824: 820: 817: 816: 804: 799: 792: 786: 784: 764: 758: 751: 746: 742: 732: 729: 728: 722: 720: 715: 710: 706: 704: 700: 690: 687: 677: 674: 670: 666: 662: 657: 655: 651: 646: 641: 637: 633: 630: 626: 622: 618: 614: 609: 606: 602: 597: 592: 587: 584: 580: 575: 570: 567: 561: 559: 555: 550: 545: 543: 538: 533: 531: 527: 521: 518: 513: 510: 505: 503: 499: 495: 490: 486: 483: 478: 474: 464: 461: 453: 443: 438: 437:poor English. 434: 430: 429: 422: 413: 412: 403: 400: 392: 382: 378: 374: 368: 367: 363: 358:This section 356: 352: 347: 346: 335: 331: 328: 325: 321: 318: 315: 314: 313: 307: 304: 301: 298: 297: 296: 289: 276: 273: 270: 269: 263: 261: 257: 252: 250: 244: 241: 239: 235: 232: 226: 224: 220: 212: 203: 201: 197: 192: 189: 185: 183: 177: 169: 167: 163: 159: 154: 152: 148: 144: 140: 136: 132: 128: 124: 123:register file 113: 110: 102: 91: 88: 84: 81: 77: 74: 70: 67: 63: 60: – 59: 55: 54:Find sources: 48: 44: 38: 37: 32:This article 30: 26: 21: 20: 2761:Chip carrier 2699:Clock gating 2618:Mixed-signal 2515:Write buffer 2492:Control unit 2466: 2304:Clock signal 2043:accelerators 2025:Cypress PSoC 1682:Simultaneous 1499:Out-of-order 1131:Neuromorphic 1012:Architecture 970:Belt machine 963:Zeno machine 896:Hierarchical 798: 770:. Retrieved 757: 745: 711: 707: 701:ISA defines 696: 683: 658: 634: 610: 588: 583:Sandy bridge 571: 562: 546: 534: 522: 514: 506: 491: 487: 479: 475: 471: 456: 447: 440:Please help 436: 425: 395: 386: 371:Please help 359: 323:capacitance. 311: 294: 253: 245: 242: 227: 216: 193: 186: 178: 175: 165: 155: 146: 139:architecture 122: 120: 105: 96: 86: 79: 72: 65: 53: 41:Please help 36:verification 33: 2546:Multiplexer 2510:Data buffer 2221:Single-core 2193:bit slicing 2051:Coprocessor 1906:Coprocessor 1787:performance 1709:Cooperative 1699:Speculative 1659:Distributed 1618:Superscalar 1603:Instruction 1571:Parallelism 1544:Speculative 1376:System/3x0 1248:Instruction 1025:Von Neumann 938:Post–Turing 494:Alpha 21264 444:if you can. 162:static RAMs 133:(CPU). The 99:August 2015 2776:Categories 2666:management 2561:Multiplier 2422:Logic gate 2412:Sequential 2319:Functional 2299:Clock rate 2272:Data cache 2245:Components 2226:Multi-core 2214:Core count 1704:Preemptive 1608:Pipelining 1591:Bit-serial 1534:Wide-issue 1479:Structural 1401:Tilera ISA 1367:MicroBlaze 1337:ETRAX CRIS 1232:Comparison 1077:Load–store 1057:Endianness 821:- Farkas, 772:13 October 737:References 223:Sense amps 69:newspapers 2600:Circuitry 2520:Microcode 2444:Registers 2287:coherence 2262:CPU cache 2120:Word size 1785:Processor 1429:Execution 1332:DEC Alpha 1310:Power ISA 1126:Cognitive 933:Universal 654:Bulldozer 625:Pentium 4 450:June 2016 360:does not 219:bit cells 2538:Datapath 2231:Manycore 2203:variable 2041:Hardware 1677:Temporal 1357:OpenRISC 1052:Cellular 1042:Dataflow 1035:modified 725:See also 629:NetBurst 617:Vortex86 613:Geode GX 605:Xeon Phi 601:Larrabee 482:datapath 426:require 2714:Related 2645:Quantum 2635:Digital 2630:Boolean 2528:Counter 2427:Quantum 2188:512-bit 2183:256-bit 2178:128-bit 2021:(MPSoC) 2006:on chip 2004:Systems 1822:(FLOPS) 1635:Process 1484:Control 1466:Hazards 1352:Itanium 1347:Unicore 1305:PowerPC 1030:Harvard 990:Pointer 985:Counter 943:Quantum 659:Unlike 621:Pentium 596:Nehalem 589:On the 574:Nehalem 542:Pentium 535:In the 428:cleanup 381:removed 366:sources 266:Decoder 238:integer 196:MODCOMP 156:Modern 83:scholar 2650:Switch 2640:Analog 2378:(IMC) 2349:(MMU) 2198:others 2173:64-bit 2168:48-bit 2163:32-bit 2158:24-bit 2153:16-bit 2148:15-bit 2143:12-bit 1980:Mobile 1896:Stream 1891:Barrel 1886:Vector 1875:(GPU) 1834:(SUPS) 1802:(IPC) 1654:Memory 1647:Vector 1630:Thread 1613:Scalar 1415:Others 1362:RISC-V 1327:SuperH 1296:Power 1292:MIPS-X 1267:PDP-11 1116:Fabric 868:Models 823:Jouppi 714:R10000 667:, and 650:Phenom 645:Athlon 566:Core 2 526:POWER8 278:short. 143:caches 85: 78: 71: 64: 56: 2706:(PPW) 2664:Power 2556:Adder 2432:Array 2399:Logic 2360:(TLB) 2343:(FPU) 2337:(AGU) 2331:(ALU) 2321:units 2257:Cache 2138:8-bit 2133:4-bit 2128:1-bit 2092:(TPU) 2086:(DSP) 2080:(PPU) 2074:(VPU) 2063:(GPU) 2032:(NoC) 2015:(SoC) 1950:(PoP) 1944:(SiP) 1938:(MCM) 1879:GPGPU 1869:(CPU) 1859:Types 1840:(PPW) 1828:(TPS) 1816:(IPS) 1808:(CPI) 1579:Level 1390:S/390 1385:S/370 1380:S/360 1322:SPARC 1300:POWER 1183:TRIPS 1151:Types 766:(PDF) 699:SPARC 665:SPARC 661:Alpha 517:SPARC 498:SPARC 283:Array 260:68000 234:R8000 129:in a 90:JSTOR 76:books 2684:ACPI 2417:Glue 2309:FIFO 2252:Core 1990:ASIP 1931:CPLD 1926:FPOA 1921:FPGA 1916:ASIC 1769:SPMD 1764:MIMD 1759:MISD 1752:SWAR 1732:SIMD 1727:SISD 1642:Data 1625:Task 1596:Word 1342:M32R 1287:MIPS 1250:sets 1217:ZISC 1212:NISC 1207:OISC 1202:MISC 1195:EPIC 1190:VLIW 1178:EDGE 1168:RISC 1163:CISC 1072:HUMA 1067:NUMA 774:2021 697:The 669:MIPS 615:and 603:and 591:Atom 515:The 509:MIPS 507:The 502:MIPS 492:The 364:any 362:cite 231:MIPS 194:The 62:news 2679:APM 2674:PMU 2566:CPU 2523:ROM 2294:Bus 1911:PAL 1586:Bit 1372:LMC 1277:ARM 1272:x86 1262:VAX 721:.) 673:ARM 636:AMD 549:MMX 537:x86 375:by 236:'s 188:x86 45:by 2778:: 2613:3D 782:^ 663:, 640:K6 558:P6 500:, 121:A 852:e 845:t 838:v 776:. 752:. 463:) 457:( 452:) 448:( 402:) 396:( 391:) 387:( 383:. 369:. 336:. 112:) 106:( 101:) 97:( 87:· 80:· 73:· 66:· 39:.

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Index