Misplaced Pages

#447552

107-589: These microprocessors implement the "Amazon", or "PowerPC-AS", instruction set architecture (ISA). Amazon is a superset of the PowerPC instruction set , with the addition of special features not in the PowerPC specification, mainly derived from POWER2 and the original AS/400 processor, and has been 64-bit from the start. The processors in this family are optimized for commercial workloads ( integer performance, large caches , frequent branches ) and do not feature

214-452: A SOI fabrication process with copper interconnects, which increased the processor's clock frequency to 600 MHz. This was the first processor implemented in this process. Architecturally however, the IStar was identical to Pulsar. The RS64-IV or Sstar was introduced in 2000 at 600 MHz, later increased to 750 MHz. Up to 16 MB DDR L2 cache was supported in the same manner as

321-501: A field-effect transistor , or may have two kinds of charge carriers in bipolar junction transistor devices. Compared with the vacuum tube , transistors are generally smaller and require less power to operate. Certain vacuum tubes have advantages over transistors at very high operating frequencies or high operating voltages, such as Traveling-wave tubes and Gyrotrons . Many types of transistors are made to standardized specifications by multiple manufacturers. The thermionic triode ,

428-532: A p-n-p transistor symbol, the arrow " P oints i N P roudly". However, this does not apply to MOSFET-based transistor symbols as the arrow is typically reversed (i.e. the arrow for the n-p-n points inside). The field-effect transistor , sometimes called a unipolar transistor , uses either electrons (in n-channel FET ) or holes (in p-channel FET ) for conduction. The four terminals of the FET are named source , gate , drain , and body ( substrate ). On most FETs,

535-476: A vacuum tube invented in 1907, enabled amplified radio technology and long-distance telephony . The triode, however, was a fragile device that consumed a substantial amount of power. In 1909, physicist William Eccles discovered the crystal diode oscillator . Physicist Julius Edgar Lilienfeld filed a patent for a field-effect transistor (FET) in Canada in 1925, intended as a solid-state replacement for

642-505: A basic ALU operation, such as "add", with the access of one or more operands in memory (using addressing modes such as direct, indirect, indexed, etc.). Certain architectures may allow two or three operands (including the result) directly in memory or may be able to perform functions such as automatic pointer increment, etc. Software-implemented instruction sets may have even more complex and powerful instructions. Reduced instruction-set computers , RISC , were first widely implemented during

749-401: A cache line or virtual memory page boundary, for instance), and are therefore somewhat easier to optimize for speed. In early 1960s computers, main memory was expensive and very limited, even on mainframes. Minimizing the size of a program to make sure it would fit in the limited memory was often central. Thus the size of the instructions needed to perform a particular task, the code density ,

856-415: A conditional branch instruction will transfer control if the condition is true, so that execution proceeds to a different part of the program, and not transfer control if the condition is false, so that execution continues sequentially. Some instruction sets also have conditional moves, so that the move will be executed, and the data stored in the target location, if the condition is true, and not executed, and

963-578: A device had been built. In 1934, inventor Oskar Heil patented a similar device in Europe. From November 17 to December 23, 1947, John Bardeen and Walter Brattain at AT&T 's Bell Labs in Murray Hill, New Jersey , performed experiments and observed that when two gold point contacts were applied to a crystal of germanium , a signal was produced with the output power greater than the input. Solid State Physics Group leader William Shockley saw

1070-600: A few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved. Modern transistor audio amplifiers of up to a few hundred watts are common and relatively inexpensive. Before transistors were developed, vacuum (electron) tubes (or in the UK "thermionic valves" or just "valves") were the main active components in electronic equipment. The key advantages that have allowed transistors to replace vacuum tubes in most applications are Transistors may have

1177-425: A field-effect transistor (FET) by trying to modulate the conductivity of a semiconductor, but was unsuccessful, mainly due to problems with the surface states , the dangling bond , and the germanium and copper compound materials. Trying to understand the mysterious reasons behind this failure led them instead to invent the bipolar point-contact and junction transistors . In 1948, the point-contact transistor

SECTION 10

#1732780130448

1284-418: A five-stage pipeline and a 256-bit wide L2 cache bus, which provided the processor with 14.4 GB/s of bandwidth from the 8 MiB L2 cache, implemented with 225 MHz DDR SRAMs. The RS64-III has 34 million transistors, a die size of 140 mm², and is manufactured on the 0.22 μm CMOS 7S process with six levels of copper interconnect . In 2000, IBM launched a refined version called IStar manufactured with

1391-572: A given instruction may specify: More complex operations are built up by combining these simple instructions, which are executed sequentially, or as otherwise directed by control flow instructions. Examples of operations common to many instruction sets include: Processors may include "complex" instructions in their instruction set. A single "complex" instruction does something that may take many instructions on other computers. Such instructions are typified by instructions that take multiple steps, control multiple functional units, or otherwise appear on

1498-481: A high-latency event ( L2 cache miss, etc.) the background thread is switched to, on the second logical processor from the OS's point of view. In the event of a "less long" latency event (L1 miss, etc.), thread switching will only occur if the background thread is ready to execute. If the background thread is also waiting for a miss, thread switching will not occur. IBM calls this scheme "coarse grained multithreading". It

1605-601: A larger scale than the bulk of simple instructions implemented by the given processor. Some examples of "complex" instructions include: Complex instructions are more common in CISC instruction sets than in RISC instruction sets, but RISC instruction sets may include them as well. RISC instruction sets generally do not include ALU operations with memory operands, or instructions to move large blocks of memory, but most RISC instruction sets include SIMD or vector instructions that perform

1712-562: A low-end single-chip PowerPC processor with AS/400 extensions. In 1995, IBM released the Cobra , or A10 processor, the first full implementation of PowerPC AS, for the IBM AS/400 systems. It was a single-chip processor running at 50-77 MHz. It was designed with a semi-custom methodology, as a consequence of time-to-market constraints. The die contains 4.7 million transistors and measures 14.6 mm by 14.6 mm (213 mm). It

1819-579: A more complete PowerPC ISA and was therefore set to be used in RS/6000 machines as well as in AS/400 systems. It featured 128 KB total on-die L1 cache , 4 MB full speed off-chip L2 on a 128-bit bus, and a clock of 125 MHz. It scaled to a 12-processor SMP configuration in IBM's machines. RS64 was called A35 in AS/400 and was one time referred to as the PowerPC 625 , between the defunct PowerPC 620 and

1926-412: A particular type, varies depending on the collector current. In the example of a light-switch circuit, as shown, the resistor is chosen to provide enough base current to ensure the transistor is saturated. The base resistor value is calculated from the supply voltage, transistor C-E junction voltage drop, collector current, and amplification factor beta. The common-emitter amplifier is designed so that

2033-419: A period of rapidly growing memory subsystems. They sacrifice code density to simplify implementation circuitry, and try to increase performance via higher clock frequencies and more registers. A single RISC instruction typically performs only a single operation, such as an "add" of registers or a "load" from a memory location into a register. A RISC instruction set normally has a fixed instruction length , whereas

2140-467: A silicon MOS transistor in 1959 and successfully demonstrated a working MOS device with their Bell Labs team in 1960. Their team included E. E. LaBate and E. I. Povilonis who fabricated the device; M. O. Thurston, L. A. D’Asaro, and J. R. Ligenza who developed the diffusion processes, and H. K. Gummel and R. Lindner who characterized the device. With its high scalability , much lower power consumption, and higher density than bipolar junction transistors,

2247-543: A single architecture for a series of five processors spanning a wide range of cost and performance. None of the five engineering design teams could count on being able to bring about adjustments in architectural specifications as a way of easing difficulties in achieving cost and performance objectives. Some virtual machines that support bytecode as their ISA such as Smalltalk , the Java virtual machine , and Microsoft 's Common Language Runtime , implement this by translating

SECTION 20

#1732780130448

2354-545: A single instruction. Some exotic instruction sets do not have an opcode field, such as transport triggered architectures (TTA), only operand(s). Most stack machines have " 0-operand " instruction sets in which arithmetic and logical operations lack any operand specifier fields; only instructions that push operands onto the evaluation stack or that pop operands from the stack into variables have operand specifiers. The instruction set carries out most ALU actions with postfix ( reverse Polish notation ) operations that work only on

2461-605: A small change in voltage ( V in ) changes the small current through the base of the transistor whose current amplification combined with the properties of the circuit means that small swings in V in produce large changes in V out . Various configurations of single transistor amplifiers are possible, with some providing current gain, some voltage gain, and some both. From mobile phones to televisions , vast numbers of products include amplifiers for sound reproduction , radio transmission , and signal processing . The first discrete-transistor audio amplifiers barely supplied

2568-408: A standard and compatible application binary interface (ABI) for a particular ISA, machine code will run on future implementations of that ISA and operating system. However, if an ISA supports running multiple operating systems, it does not guarantee that machine code for one operating system will run on another operating system, unless the first operating system supports running machine code built for

2675-440: A type of 3D non-planar multi-gate MOSFET, originated from the research of Digh Hisamoto and his team at Hitachi Central Research Laboratory in 1989. Because transistors are the key active components in practically all modern electronics , many people consider them one of the 20th century's greatest inventions. The invention of the first transistor at Bell Labs was named an IEEE Milestone in 2009. Other Milestones include

2782-463: A typical CISC instruction set has instructions of widely varying length. However, as RISC computers normally require more and often longer instructions to implement a given task, they inherently make less optimal use of bus bandwidth and cache memories. Certain embedded RISC ISAs like Thumb and AVR32 typically exhibit very high density owing to a technique called code compression. This technique packs two 16-bit instructions into one 32-bit word, which

2889-416: A weaker input signal, acting as an amplifier . It can also be used as an electrically controlled switch , where the amount of current is determined by other circuit elements. There are two types of transistors, with slight differences in how they are used: The top image in this section represents a typical bipolar transistor in a circuit. A charge flows between emitter and collector terminals depending on

2996-461: A working bipolar NPN junction amplifying germanium transistor. Bell announced the discovery of this new "sandwich" transistor in a press release on July 4, 1951. The first high-frequency transistor was the surface-barrier germanium transistor developed by Philco in 1953, capable of operating at frequencies up to 60 MHz . They were made by etching depressions into an n-type germanium base from both sides with jets of indium(III) sulfate until it

3103-540: A writable control store use it to allow the instruction set to be changed (for example, the Rekursiv processor and the Imsys Cjip ). CPUs designed for reconfigurable computing may use field-programmable gate arrays (FPGAs). An ISA can also be emulated in software by an interpreter . Naturally, due to the interpretation overhead, this is slower than directly running programs on the emulated hardware, unless

3210-415: Is 15 bytes (120 bits). Within an instruction set, different instructions may have different lengths. In some architectures, notably most reduced instruction set computers (RISC), instructions are a fixed length , typically corresponding with that architecture's word size . In other architectures, instructions have variable length , typically integral multiples of a byte or a halfword . Some, such as

3317-444: Is a complex issue. There were two stages in history for the microprocessor. The first was the CISC (Complex Instruction Set Computer), which had many different instructions. In the 1970s, however, places like IBM did research and found that many instructions in the set could be eliminated. The result was the RISC (Reduced Instruction Set Computer), an architecture that uses a smaller set of instructions. A simpler instruction set may offer

IBM RS64 - Misplaced Pages Continue

3424-520: Is composed of semiconductor material , usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits . Because transistors are

3531-602: Is due to the many addressing modes and optimizations (such as sub-register addressing, memory operands in ALU instructions, absolute addressing, PC-relative addressing, and register-to-register spills) that CISC ISAs offer. The size or length of an instruction varies widely, from as little as four bits in some microcontrollers to many hundreds of bits in some VLIW systems. Processors used in personal computers , mainframes , and supercomputers have minimum instruction sizes between 8 and 64 bits. The longest possible instruction on x86

3638-521: Is not exactly the same thing as simultaneous multithreading as found on later Pentium 4 processors. An IBM paper notes that the coarse grained scheme is a better fit for an in-order microarchitecture like RS64. RS64-II was called A50 in AS/400 systems. The RS64-III or Pulsar was introduced in 1999 at 450 MHz. Key changes included larger 128 KiB L1 instruction and data caches, improved branch prediction accuracy and reduced branch misprediction penalties of zero or one cycle. The RS64-III has

3745-481: Is not observed in modern devices, for example, at the 65 nm technology node. For low noise at narrow bandwidth , the higher input resistance of the FET is advantageous. FETs are divided into two families: junction FET ( JFET ) and insulated gate FET (IGFET). The IGFET is more commonly known as a metal–oxide–semiconductor FET ( MOSFET ), reflecting its original construction from layers of metal (the gate), oxide (the insulation), and semiconductor. Unlike IGFETs,

3852-421: Is often easier and cheaper to use a standard microcontroller and write a computer program to carry out a control function than to design an equivalent mechanical system. A transistor can use a small signal applied between one pair of its terminals to control a much larger signal at another pair of terminals, a property called gain . It can produce a stronger output signal, a voltage or current, proportional to

3959-553: Is similar to the code density of RISC; the increased instruction density is offset by requiring more of the primitive instructions to do a task. There has been research into executable compression as a mechanism for improving code density. The mathematics of Kolmogorov complexity describes the challenges and limits of this. In practice, code density is also dependent on the compiler . Most optimizing compilers have options that control whether to optimize code generation for execution speed or for code density. For instance GCC has

4066-432: Is then unpacked at the decode stage and executed as two instructions. Minimal instruction set computers (MISC) are commonly a form of stack machine , where there are few separate instructions (8–32), so that multiple instructions can be fit into a single machine word. These types of cores often take little silicon to implement, so they can be easily realized in an FPGA or in a multi-core form. The code density of MISC

4173-504: The ARM with Thumb-extension have mixed variable encoding, that is two fixed, usually 32-bit and 16-bit encodings, where instructions cannot be mixed freely but must be switched between on a branch (or exception boundary in ARMv8). Fixed-length instructions are less complicated to handle than variable-length instructions for several reasons (not having to check whether an instruction straddles

4280-489: The CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an implementation of that ISA. In general, an ISA defines the supported instructions , data types , registers , the hardware support for managing main memory , fundamental features (such as the memory consistency , addressing modes , virtual memory ), and

4387-411: The compiler responsible for instruction issue and scheduling. Architectures with even less complexity have been studied, such as the minimal instruction set computer (MISC) and one-instruction set computer (OISC). These are theoretically important types, but have not been commercialized. Machine language is built up from discrete statements or instructions . On the processing architecture,

IBM RS64 - Misplaced Pages Continue

4494-521: The input/output model of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance , physical size, and monetary cost (among other things), but that are capable of running

4601-439: The instruction pipeline only allow a single memory load or memory store per instruction, leading to a load–store architecture (RISC). For another example, some early ways of implementing the instruction pipeline led to a delay slot . Transistor A transistor is a semiconductor device used to amplify or switch electrical signals and power . It is one of the basic building blocks of modern electronics . It

4708-529: The microarchitecture of a processor, engineers use blocks of "hard-wired" electronic circuitry (often designed separately) such as adders, multiplexers, counters, registers, ALUs, etc. Some kind of register transfer language is then often used to describe the decoding and sequencing of each instruction of an ISA using this physical microarchitecture. There are two basic ways to build a control unit to implement this description (although many designs use middle ways or compromises): Some microcoded CPU designs with

4815-457: The stack or in an implicit register. If some of the operands are given implicitly, fewer operands need be specified in the instruction. When a "destination operand" explicitly specifies the destination, an additional operand must be supplied. Consequently, the number of operands encoded in an instruction may differ from the mathematically necessary number of arguments for a logical or arithmetic operation (the arity ). Operands are either encoded in

4922-399: The surface state barrier that prevented the external electric field from penetrating the material. In 1955, Carl Frosch and Lincoln Derick accidentally grew a layer of silicon dioxide over the silicon wafer, for which they observed surface passivation effects. By 1957 Frosch and Derick, using masking and predeposition, were able to manufacture silicon dioxide field effect transistors;

5029-504: The x86 instruction set , but they have radically different internal designs. The concept of an architecture , distinct from the design of a specific machine, was developed by Fred Brooks at IBM during the design phase of System/360 . Prior to NPL [System/360], the company's computer designers had been free to honor cost objectives not only by selecting technologies but also by fashioning functional and architectural refinements. The SPREAD compatibility objective, in contrast, postulated

5136-513: The "Amazon Star"). The Bellatrix project was extremely ambitious in its pervasive use of self-timed & pulse-based circuits and the EDA tools required to support this design strategy, and was eventually terminated. To address technical workstation, supercomputer , and engineering/scientific markets, IBM Austin (the home of the RS/6000s) then started developing a time-to-market single-chip version of

5243-431: The "opcode" representation of the instruction, or else are given as values or addresses following the opcode. Register pressure measures the availability of free registers at any point in time during the program execution. Register pressure is high when a large number of the available registers are in use; thus, the higher the register pressure, the more often the register contents must be spilled into memory. Increasing

5350-702: The 1956 Nobel Prize in Physics for their achievement. The most widely used type of transistor is the metal–oxide–semiconductor field-effect transistor (MOSFET), the MOSFET was invented at Bell Labs between 1955 and 1960. Transistors revolutionized the field of electronics and paved the way for smaller and cheaper radios , calculators , computers , and other electronic devices. Most transistors are made from very pure silicon , and some from germanium , but certain other semiconductor materials are sometimes used. A transistor may have only one kind of charge carrier in

5457-412: The MOSFET made it possible to build high-density integrated circuits, allowing the integration of more than 10,000 transistors in a single IC. Bardeen and Brattain's 1948 inversion layer concept forms the basis of CMOS technology today. The CMOS (complementary MOS ) was invented by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. The first report of a floating-gate MOSFET

SECTION 50

#1732780130448

5564-643: The Power2 (P2SC) in parallel with the development of a sophisticated 64-bit PowerPC processor with the POWER2 extensions and twin sophisticated MAF floating-point units (the POWER3/630). To address RS/6000 commercial applications and AS/400 systems, IBM Rochester (the home of the AS/400s) started developing the first of the high-end 64-bit PowerPC processors with AS/400 extensions, and IBM Endicott started developing

5671-451: The PowerPC 630 (later renamed POWER3 ). It was manufactured with a BiCMOS fabrication process. The RS64-II or Northstar was introduced at 262 MHz in 1998 with 8 MB of full speed L2 on a 256 bit 6XX bus (also used in PowerPC 620 and POWER3 ). Processor boards containing 4 RS64-II's could be swapped into machines designed for similar 4-way RS64 boards, avoiding a "fork lift upgrade". The RS64-II contained 12.5 million transistors,

5778-531: The RS-64 IV was similar to the Sun Microsystems processors with which it competed, though its floating point power was not comparable to the contemporary POWER3-II , which remained reasonably competitive throughout its lifecycle. Instruction set architecture In computer science , an instruction set architecture ( ISA ) is an abstract model that generally defines how software controls

5885-581: The RS64-III (19.2 GB/s bandwidth). The RS64-IV had 44 million transistors and was 128 mm² large manufactured on a 0.18 μm process. Unlike POWER, energy consumption remained low, at under 15 watts per core. For a time, while the POWER line stagnated at half the clock speed of its competitors, the RS64 family was at the top of the IBM large SMP UNIX server line. The integer / commercial workload performance of

5992-775: The Regency Division of Industrial Development Engineering Associates, I.D.E.A. and Texas Instruments of Dallas, Texas, the TR-1 was manufactured in Indianapolis, Indiana. It was a near pocket-sized radio with four transistors and one germanium diode. The industrial design was outsourced to the Chicago firm of Painter, Teague and Petertil. It was initially released in one of six colours: black, ivory, mandarin red, cloud grey, mahogany and olive green. Other colours shortly followed. The first production all-transistor car radio

6099-431: The basis of modern digital electronics since the late 20th century, paving the way for the digital age . The US Patent and Trademark Office calls it a "groundbreaking invention that transformed life and culture around the world". Its ability to be mass-produced by a highly automated process ( semiconductor device fabrication ), from relatively basic materials, allows astonishingly low per-transistor costs. MOSFETs are

6206-404: The body is connected to the source inside the package, and this will be assumed for the following description. In a FET, the drain-to-source current flows via a conducting channel that connects the source region to the drain region. The conductivity is varied by the electric field that is produced when a voltage is applied between the gate and source terminals, hence the current flowing between

6313-595: The bytecode for commonly used code paths into native machine code. In addition, these virtual machines execute less frequently used code paths by interpretation (see: Just-in-time compilation ). Transmeta implemented the x86 instruction set atop VLIW processors in this fashion. An ISA may be classified in a number of different ways. A common classification is by architectural complexity . A complex instruction set computer (CISC) has many specialized instructions, some of which may only be rarely used in practical programs. A reduced instruction set computer (RISC) simplifies

6420-437: The collector to the emitter. If the voltage difference between the collector and emitter were zero (or near zero), the collector current would be limited only by the load resistance (light bulb) and the supply voltage. This is called saturation because the current is flowing from collector to emitter freely. When saturated, the switch is said to be on . The use of bipolar transistors for switching applications requires biasing

6527-445: The concept of an inversion layer, forms the basis of CMOS and DRAM technology today. In the early years of the semiconductor industry , companies focused on the junction transistor , a relatively bulky device that was difficult to mass-produce , limiting it to several specialized applications. Field-effect transistors (FETs) were theorized as potential alternatives, but researchers could not get them to work properly, largely due to

SECTION 60

#1732780130448

6634-559: The current in the base. Because the base and emitter connections behave like a semiconductor diode, a voltage drop develops between them. The amount of this drop, determined by the transistor's material, is referred to as V BE . (Base Emitter Voltage) Transistors are commonly used in digital circuits as electronic switches which can be either in an "on" or "off" state, both for high-power applications such as switched-mode power supplies and for low-power applications such as logic gates . Important parameters for this application include

6741-456: The current switched, the voltage handled, and the switching speed, characterized by the rise and fall times . In a switching circuit, the goal is to simulate, as near as possible, the ideal switch having the properties of an open circuit when off, the short circuit when on, and an instantaneous transition between the two states. Parameters are chosen such that the "off" output is limited to leakage currents too small to affect connected circuitry,

6848-460: The drain and source is controlled by the voltage applied between the gate and source. As the gate–source voltage ( V GS ) is increased, the drain–source current ( I DS ) increases exponentially for V GS below threshold, and then at a roughly quadratic rate: ( I DS ∝ ( V GS − V T ) , where V T is the threshold voltage at which drain current begins) in the " space-charge-limited " region above threshold. A quadratic behavior

6955-434: The existing instruction set required extensions for the commercial applications on the AS/400. At Kuehler's insistence, a team at Rochester led by Frank Soltis investigated the feasibility of extending the PowerPC instruction set to support the needs of the AS/400 platform. These extensions became known as Amazon and were selected by IBM executive management for further development over continued development of C-RISC. At

7062-406: The expression stack , not on data registers or arbitrary main memory cells. This can be very convenient for compiling high-level languages, because most arithmetic expressions can be easily translated into postfix notation. Conditional instructions often have a predicate field—a few bits that encode the specific condition to cause an operation to be performed rather than not performed. For example,

7169-463: The first planar transistors, in which drain and source were adjacent at the same surface. They showed that silicon dioxide insulated, protected silicon wafers and prevented dopants from diffusing into the wafer. After this, J.R. Ligenza and W.G. Spitzer studied the mechanism of thermally grown oxides, fabricated a high quality Si/ SiO 2 stack and published their results in 1960. Following this research, Mohamed Atalla and Dawon Kahng proposed

7276-454: The following limitations: Transistors are categorized by Hence, a particular transistor may be described as silicon, surface-mount, BJT, NPN, low-power, high-frequency switch . Convenient mnemonic to remember the type of transistor (represented by an electrical symbol ) involves the direction of the arrow. For the BJT , on an n-p-n transistor symbol, the arrow will " N ot P oint i N" . On

7383-506: The full PowerPC AS ISA which were not needed for the Advanced/36. In 1996, IBM released the high-end, 4-way SMP , multi-chip version called Muskie , A25 or A30 in AS/400 systems. It ran at 125-154 MHz. It was manufactured on a BiCMOS fabrication process. These processors were only used in AS/400 and Advanced/36 machines. The RS64 or Apache was introduced in 1997. It was developed from "Cobra" and "Muskie" but included

7490-414: The hardware running the emulator is an order of magnitude faster. Today, it is common practice for vendors of new ISAs or microarchitectures to make software emulators available to software developers before the hardware implementation is ready. Often the details of the implementation have a strong influence on the particular instructions selected for the instruction set. For example, many implementations of

7597-450: The idea of a field-effect transistor that used an electric field as a "grid" was not new. Instead, what Bardeen, Brattain, and Shockley invented in 1947 was the first point-contact transistor . To acknowledge this accomplishment, Shockley, Bardeen and Brattain jointly received the 1956 Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect". Shockley's team initially attempted to build

7704-546: The instruction set includes support for something such as " fetch-and-add ", " load-link/store-conditional " (LL/SC), or "atomic compare-and-swap ". A given instruction set can be implemented in a variety of ways. All ways of implementing a particular instruction set provide the same programming model , and all implementations of that instruction set are able to run the same executables. The various ways of implementing an instruction set give different tradeoffs between cost, performance, power consumption, size, etc. When designing

7811-418: The inventions of the junction transistor in 1948 and the MOSFET in 1959. The MOSFET is by far the most widely used transistor, in applications ranging from computers and electronics to communications technology such as smartphones . It has been considered the most important transistor, possibly the most important invention in electronics, and the device that enabled modern electronics. It has been

7918-489: The key active components in practically all modern electronics , many people consider them one of the 20th century's greatest inventions. Physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor (FET) in 1926, but it was not possible to construct a working device at that time. The first working device was a point-contact transistor invented in 1947 by physicists John Bardeen , Walter Brattain , and William Shockley at Bell Labs who shared

8025-663: The large number of bits needed to encode the three registers of a 3-operand instruction, RISC architectures that have 16-bit instructions are invariably 2-operand designs, such as the Atmel AVR, TI MSP430 , and some versions of ARM Thumb . RISC architectures that have 32-bit instructions are usually 3-operand designs, such as the ARM , AVR32 , MIPS , Power ISA , and SPARC architectures. Each instruction specifies some number of operands (registers, memory locations, or immediate values) explicitly . Some instructions give one or both operands implicitly, such as by being stored on top of

8132-613: The mechanical encoding from punched metal cards. The first prototype pocket transistor radio was shown by INTERMETALL, a company founded by Herbert Mataré in 1952, at the Internationale Funkausstellung Düsseldorf from August 29 to September 6, 1953. The first production-model pocket transistor radio was the Regency TR-1 , released in October 1954. Produced as a joint venture between

8239-543: The most fundamental abstractions in computing . An instruction set architecture is distinguished from a microarchitecture , which is the set of processor design techniques used, in a particular processor, to implement the instruction set. Processors with different microarchitectures can share a common instruction set. For example, the Intel Pentium and the AMD Athlon implement nearly identical versions of

8346-927: The most numerously produced artificial objects in history, with more than 13 sextillion manufactured by 2018. Although several companies each produce over a billion individually packaged (known as discrete ) MOS transistors every year, the vast majority are produced in integrated circuits (also known as ICs , microchips, or simply chips ), along with diodes , resistors , capacitors and other electronic components , to produce complete electronic circuits. A logic gate consists of up to about 20 transistors, whereas an advanced microprocessor , as of 2022, may contain as many as 57 billion MOSFETs. Transistors are often organized into logic gates in microprocessors to perform computation. The transistor's low cost, flexibility and reliability have made it ubiquitous. Transistorized mechatronic circuits have replaced electromechanical devices in controlling appliances and machinery. It

8453-401: The number of registers in an architecture decreases register pressure but increases the cost. While embedded instruction sets such as Thumb suffer from extremely high register pressure because they have small register sets, general-purpose RISC ISAs like MIPS and Alpha enjoy low register pressure. CISC ISAs like x86-64 offer low register pressure despite having smaller register sets. This

8560-439: The operation to perform, such as add contents of memory to register —and zero or more operand specifiers, which may specify registers , memory locations, or literal data. The operand specifiers may have addressing modes determining their meaning or may be in fixed fields. In very long instruction word (VLIW) architectures, which include many microcode architectures, multiple simultaneous opcodes and operands are specified in

8667-447: The option -Os to optimize for small machine code size, and -O3 to optimize for execution speed at the cost of larger machine code. The instructions constituting a program are rarely specified using their internal, numeric form ( machine code ); they may be specified by programmers using an assembly language or, more commonly, may be generated from high-level programming languages by compilers . The design of instruction sets

8774-451: The other operating system. An ISA can be extended by adding instructions or other capabilities, or adding support for larger addresses and data values; an implementation of the extended ISA will still be able to execute machine code for versions of the ISA without those extensions. Machine code using those extensions will only run on implementations that support those extensions. The binary compatibility that they provide makes ISAs one of

8881-476: The potential for higher speeds, reduced processor size, and reduced power consumption. However, a more complex set may optimize common operations, improve memory and cache efficiency, or simplify programming. Some instruction set designers reserve one or more opcodes for some kind of system call or software interrupt . For example, MOS Technology 6502 uses 00 H , Zilog Z80 uses the eight codes C7,CF,D7,DF,E7,EF,F7,FF H while Motorola 68000 use codes in

8988-548: The potential in this, and over the next few months worked to greatly expand the knowledge of semiconductors . The term transistor was coined by John R. Pierce as a contraction of the term transresistance . According to Lillian Hoddeson and Vicki Daitch, Shockley proposed that Bell Labs' first patent for a transistor should be based on the field-effect and that he be named as the inventor. Having unearthed Lilienfeld's patents that went into obscurity years earlier, lawyers at Bell Labs advised against Shockley's proposal because

9095-570: The processor by efficiently implementing only the instructions that are frequently used in programs, while the less common operations are implemented as subroutines, having their resulting additional processor execution time offset by infrequent use. Other types include very long instruction word (VLIW) architectures, and the closely related long instruction word (LIW) and explicitly parallel instruction computing (EPIC) architectures. These architectures seek to exploit instruction-level parallelism with less hardware than RISC and CISC by making

9202-479: The range A000..AFFF H . Fast virtual machines are much easier to implement if an instruction set meets the Popek and Goldberg virtualization requirements . The NOP slide used in immunity-aware programming is much easier to implement if the "unprogrammed" state of the memory is interpreted as a NOP . On systems with multiple processors, non-blocking synchronization algorithms are much easier to implement if

9309-461: The requirements of the cost-focused Apple Power Mac, high-performance and RAS RS/6000 systems, and the AS/400 transition to PowerPC. Amazon was extended to support those features as well, so that processors could be designed for use in both high-end RS/6000 and AS/400 machines. The project to develop the first such processor was "Bellatrix" (the name of a star in the Orion constellation , also called

9416-405: The resistance of the transistor in the "on" state is too small to affect circuitry, and the transition between the two states is fast enough not to have a detrimental effect. In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises, the emitter and collector currents rise exponentially. The collector voltage drops because of reduced resistance from

9523-488: The same arithmetic operation on multiple pieces of data at the same time. SIMD instructions have the ability of manipulating large vectors and matrices in minimal time. SIMD instructions allow easy parallelization of algorithms commonly involved in sound, image, and video processing. Various SIMD implementations have been brought to market under trade names such as MMX , 3DNow! , and AltiVec . On traditional architectures, an instruction includes an opcode that specifies

9630-433: The same machine code, so that a lower-performance, lower-cost machine can be replaced with a higher-cost, higher-performance machine without having to replace software. It also enables the evolution of the microarchitectures of the implementations of that ISA, so that a newer, higher-performance implementation of an ISA can run software that runs on previous generations of implementations. If an operating system maintains

9737-671: The same time, the RS/6000 developers were broadly expanding their product line to include systems which spanned from low-end workstations , to mainframe -competitor large enterprise SMP systems, to clustered RS/6000-SP2 supercomputing systems. PowerPC processors developed in the AIM alliance suited the low-end RISC workstation and small server space well. But mainframe and large clustered supercomputing systems required more performance and reliability, availability and serviceability features than processors designed for Apple Power Macs . Multiple processor designs were required to simultaneously meet

9844-621: The strong floating point performance of the processors in the POWER family, its sibling. The RS64 family was phased out soon after the introduction of the POWER4 , which was developed to unite the RS64 and POWER families. In 1990, the AS/400 engineering team at IBM Rochester began work on a new architecture known as C-RISC (Commercial RISC ) to replace the IMPI architecture of the AS/400. C-RISC

9951-524: The target location not modified, if the condition is false. Similarly, IBM z/Architecture has a conditional store instruction. A few instruction sets include a predicate field in every instruction; this is called branch predication . Instruction sets may be categorized by the maximum number of operands explicitly specified in instructions. (In the examples that follow, a , b , and c are (direct or calculated) addresses referring to memory cells, while reg1 and so on refer to machine registers.) Due to

10058-409: The transistor so that it operates between its cut-off region in the off-state and the saturation region ( on ). This requires sufficient base drive current. As the transistor provides current gain, it facilitates the switching of a relatively large current in the collector by a much smaller current into the base terminal. The ratio of these currents varies depending on the type of transistor, and even for

10165-483: The transistor, the company rushed to get its "transistron" into production for amplified use in France's telephone network, filing his first transistor patent application on August 13, 1948. The first bipolar junction transistors were invented by Bell Labs' William Shockley, who applied for patent (2,569,347) on June 26, 1948. On April 12, 1950, Bell Labs chemists Gordon Teal and Morgan Sparks successfully produced

10272-486: The triode. He filed identical patents in the United States in 1926 and 1928. However, he did not publish any research articles about his devices nor did his patents cite any specific examples of a working prototype. Because the production of high-quality semiconductor materials was still decades away, Lilienfeld's solid-state amplifier ideas would not have found practical use in the 1920s and 1930s, even if such

10379-408: The widespread adoption of transistor radios. Seven million TR-63s were sold worldwide by the mid-1960s. Sony's success with transistor radios led to transistors replacing vacuum tubes as the dominant electronic technology in the late 1950s. The first working silicon transistor was developed at Bell Labs on January 26, 1954, by Morris Tanenbaum . The first production commercial silicon transistor

10486-409: Was 162 mm² large and drew 27 watts maximum power. Manufacturing changed to a 0.35 μm CMOS fabrication. RS64-II was the first mass-market processor to implement multithreading . Essentially, each chip stores state information for 2 threads at any given time and appears to be two processors to the OS. One logical processor runs what is called the foreground thread. When this thread encounters

10593-525: Was a few ten-thousandths of an inch thick. Indium electroplated into the depressions formed the collector and emitter. AT&T first used transistors in telecommunications equipment in the No. 4A Toll Crossbar Switching System in 1953, for selecting trunk circuits from routing information encoded on translator cards. Its predecessor, the Western Electric No. 3A phototransistor , read

10700-430: Was an evolution of the IMPI instruction set, extending the address space to 96 bits and adding some RISC instructions to speed up the more computationally intensive commercial applications that were being created for AS/400s. IBM president Jack Kuehler wanted them to use PowerPC, but they resisted, arguing that the existing 32/64-bit PowerPC instruction set would not enable a viable transition for OS/400 software and that

10807-753: Was an important characteristic of any instruction set. It remained important on the initially-tiny memories of minicomputers and then microprocessors. Density remains important today, for smartphone applications, applications downloaded into browsers over slow Internet connections, and in ROMs for embedded applications. A more general advantage of increased density is improved effectiveness of caches and instruction prefetch. Computers with high code density often have complex instructions for procedure entry, parameterized returns, loops, etc. (therefore retroactively named Complex Instruction Set Computers , CISC ). However, more typical, or frequent, "CISC" instructions merely combine

10914-486: Was announced by Texas Instruments in May 1954. This was the work of Gordon Teal , an expert in growing crystals of high purity, who had previously worked at Bell Labs. The basic principle of the field-effect transistor (FET) was first proposed by physicist Julius Edgar Lilienfeld when he filed a patent for a device similar to MESFET in 1926, and for an insulated-gate field-effect transistor in 1928. The FET concept

11021-521: Was developed by Chrysler and Philco corporations and was announced in the April 28, 1955, edition of The Wall Street Journal . Chrysler made the Mopar model 914HR available as an option starting in fall 1955 for its new line of 1956 Chrysler and Imperial cars, which reached dealership showrooms on October 21, 1955. The Sony TR-63, released in 1957, was the first mass-produced transistor radio, leading to

11128-461: Was fabricated by IBM in their CMOS 5L process, a 0.5  μm , four-layer-metal CMOS process. It used a 3.0 V power supply and dissipated 17.7 W maximum, 13.4 W minimum at 77 MHz. It was packaged in a 625-contact ceramic ball grid array (CBGA) that measured 32 mm by 32 mm. Cobra was preceded by a simplified implementation known as Cobra-Lite in 1994, which was used in the first IBM Advanced/36 systems. It lacked 17 instructions from

11235-918: Was independently invented by physicists Herbert Mataré and Heinrich Welker while working at the Compagnie des Freins et Signaux Westinghouse , a Westinghouse subsidiary in Paris . Mataré had previous experience in developing crystal rectifiers from silicon and germanium in the German radar effort during World War II . With this knowledge, he began researching the phenomenon of "interference" in 1947. By June 1948, witnessing currents flowing through point-contacts, he produced consistent results using samples of germanium produced by Welker, similar to what Bardeen and Brattain had accomplished earlier in December 1947. Realizing that Bell Labs' scientists had already invented

11342-455: Was later also theorized by engineer Oskar Heil in the 1930s and by William Shockley in the 1940s. In 1945 JFET was patented by Heinrich Welker . Following Shockley's theoretical treatment on JFET in 1952, a working practical JFET was made in 1953 by George C. Dacey and Ian M. Ross . In 1948, Bardeen and Brattain patented the progenitor of MOSFET at Bell Labs, an insulated-gate FET (IGFET) with an inversion layer. Bardeen's patent, and

11449-521: Was made by Dawon Kahng and Simon Sze in 1967. In 1967, Bell Labs researchers Robert Kerwin, Donald Klein and John Sarace developed the self-aligned gate (silicon-gate) MOS transistor, which Fairchild Semiconductor researchers Federico Faggin and Tom Klein used to develop the first silicon-gate MOS integrated circuit . A double-gate MOSFET was first demonstrated in 1984 by Electrotechnical Laboratory researchers Toshihiro Sekigawa and Yutaka Hayashi. The FinFET (fin field-effect transistor),

#447552