Microprocessor
From open-encyclopedia.com - the free encyclopedia.
A microprocessor (abbreviated as µP or uP) is an electronic computer central processing unit (CPU) made from miniaturized transistors and other circuit elements on a single semiconductor integrated circuit (IC) (aka microchip or just chip).
Before the advent of microprocessors, electronic CPUs were made from discrete (separate) TTL integrated circuits; before that, individual transistors; and before that, from vacuum tubes. There have even been designs for simple computing machines based on mechanical parts such as gears, shafts, levers, Tinkertoys, etc. Leonardo DaVinci made one such design, although none were possible to construct using the manufacturing techniques of the time.
The evolution of microprocessors have been known to follow Moore's Law when it comes to steadily increasing performance over the years.
| Contents |
History
Contrary to popular opinion, Intel did not necessarily invent the microprocessor. The printer company Dataproducts of San Antonio TX issued a memorandum seeking a proposal for a single-chip controller for a new printer model. Texas Instruments (TI) developed the TMS 1000 and Intel developed the i4004. Neither met the exact set of selection criteria (notably cost per unit and quantity yield), and the printer project was canceled. Faced with this rejection, the two companies then marketed their new chips differently. TI stressed embedded applications, and introduced a version of the TMS 1000, called the TMS1802NC on September 17, 1971, which implemented a calculator on a chip. This beat Intel's introduction of the 4004 by two months.
During its development, Intel apparently did not keep adequate lab records for a patent. Apparently TI did, and filed for the patent on the microprocessor. Gary Boone was awarded U.S. Patent No. 3,757,306 for the single-chip microprocessor architecture on September 4, 1973. Thus, from both a legal and a marketing standpoint, TI invented the microprocessor and also the single-chip calculator. It may never be known which company actually had the first working microprocessor running on the lab bench. By the way, Jack S. Kilby, also of TI, had invented the integrated circuit on September 12, 1958.
A microcomputer is a variation of a microprocessor which combines the microprocessor (CPU), memory, and I/O (input/output) lines, all on one chip. The microcomputer patent, number 4,074,351, was awarded to Gary Boone and Michael J. Cochran of TI.
The Intel chip was the 4-bit 4004, released on November 15, 1971, developed by Federico Faggin. The 4004 was later followed by the 8008, the world's first 8-bit microprocessor. These processors are the precursors to the very successful Intel 8080, Zilog Z80, and derivative Intel 8-bit processors. The competing Motorola 6800 architecture was cloned and improved in the MOS Technology 6502, rivaling the Z80 in popularity during the 1980s.
Another 8-bit microprocessor was the Signetics 2650, which enjoyed a brief flurry of interest due to its innovative and powerful instruction set architecture.
The first multi-chip 16-bit microprocessor was introduced by either Digital Equipment Corporation (DEC) in its LSI-11 OEM board set and its packaged PDP 11/03 minicomputer, or by Fairchild Semiconductor with its MicroFlame 9440, both in the 1975 to 1976 timeframe. The first single-chip 16-bit microprocessor was the TI TMS 9900, which was also compatible with the TI 990 line of minicomputers, and used in the TM990 line of OEM microcomputer boards. The DEC chipset later gave way to the 32-bit DEC VAX product line. The Fairchild MicroFlame ran very hot and was never chosen by a major computer manufacturer, so it just faded out of existence. The TI TMS 9900 had a strong beginning, but was packaged in a large (for the time) ceramic 64-pin package, which brought the cost out of range compared to the much cheaper 8-bit Intel 8080 and 8085. In March 1982, TI decided to start ramping down TMS 9900 production, and go into the DSP business instead.
The 8-bit Intel 8080 is the ancestor of the 16-bit Intel 8086, the first member of the x86 family which powers most modern PC type computers. Intel introduced the 8086 as a cost effective way of porting software from the 8080 lines, and succeeded in winning much business on that premise. Following up their 8086 and 8088, Intel released the 80186, 80286 and, in 1985, the 32-bit 80386, cementing their PC market dominance with the processor family's backwards compatibility.
Examples of other 16-bit microprocessor families include the Motorola 68000, used in early Apple Macintosh computers; and the Zilog Z8000.
The world's first single-chip 32-bit microprocessor was the AT&T Bell Labs BELLMAC-32A, introduced in 1980. After the divestiture of AT&T in 1984, it was renamed the WE 32000 (WE for Western Electric), and had two follow-on generations, the WE 32100 and WE 32200. These microprocessors were used in the AT&T 3B5 and 3B15 minicomputers; in the 3B2, the world's first desktop supermicrocomputer; in the "Companion", the world's first 32-bit laptop computer; and in "Alexander", the world's first book-sized supermicrocomputer, featuring ROM-pack memory cartridges similar to today's gaming consoles. All these systems ran the original Bell Labs UNIX Operating System, which included the first Windows-type software called xt-layers.
During this time (early to mid 1980s), National Semiconductor introduced a 16-bit pinout, 32-bit internal microprocessor called the NS 16032, the full 32-bit NS 32032, and a line of 32-bit industrial OEM microcomputers. By the mid-1980s, Sequent introduced the first symmetric multiprocessor (SMP) server-class computer using the NS 32032.
In 1981, Motorola introduced the MC 68000, which had a 32-bit architecture internally, but a 16-bit pinout externally. By 1985 or so, Motorola introduced its pure 32-bit microprocessors, the MC 68010, 68012, and especially the 68020. The MC 68020 became hugely popular in the UNIX supermicrocomputer market segment, and many small companies (e.g., Altos, Charles River Data Systems) produced desktop-size systems.
In the mid-1980s to early-1990s, a crop of new high-performance RISC (reduced instruction set computer) microprocessors appeared, including the CRISP (C Reduced Instruction Set Processor) from AT&T Bell Labs, the SPARC from SUN Microsystems, the MIPS R1000, R2000, & R3000 by MIPS Inc. (later bought by Silicon Graphics Inc.), the Motorola 88000 family, the IBM PC/RT and follow-on Power America (now PowerPC and RS 6000), the Digital Equipment Corporation (DEC) ALPHA (the world's first single-chip 64-bit microprocessor), and the HP Precision Architecture (HP PA-RISC).
In the late 1980s, "microprocessor wars" started killing off some of the microprocessors. Apparently, with only one major design win, Sequent, the NS 32032 just faded out of existence, and Sequent switched to Intel microprocessors. AT&T canceled both the WE 32000 and CRISP series, using MIPS and Intel chips for new equipment. NCR had designed a computer product line using the Motorola 88000, but abruptly canceled it and designed the new NCR 3000 computers with Intel Pentiums. Motorola canceled the 88000, and signed a deal with IBM to second-source the PowerPC chip, which was then incorporated into the new G-series Macintosh PCs. The DEC ALPHA was forced upon Intel for cash in the legal settlement which DEC won as it was going out of business. As of 2004, SUN, HP and IBM, continue to use their own chips in their servers, while SGI's MIPS enjoys a niche in its high-end workstations, inside Cisco routers, and in some gaming console gear. Of course, in the IBM-compatible PC world, Intel, AMD, and now VIA of Taiwan all make x86-compatible microprocessors.
In 64-bit computing, the DEC(-Intel) ALPHA, the AMD 64, and the HP-Intel Itanium are the most popular designs as of late 2004.
Market statistics
In 2003, about 44 billion US$ worth of microprocessors were manufactured and sold. [1] Although about half of that money was spent on CPUs used in desktop or laptop personal computers, those count for only about 0.2% of all CPUs sold.
About 55% of all CPUs sold in the world are 8-bit microcontrollers. Over 2 billion 8-bit microcontrollers were sold in 1997. [2]
Less than 10% of all the CPUs sold in the world are 32-bit or more. Of all the 32-bit CPUs sold, about 2% are used in desktop or laptop personal computers. "Taken as a whole, the average price for a microprocessor, microcontroller, or DSP is just over $6." [3]
Common µPs and architectures
- AMD K5, K6, K6-2, K6-III, Duron, Athlon
- AMD Opteron
- ARM family, StrongARM
- Atmel AVR architecture (purely microcontrollers)
- CDP1802 (aka RCA COSMAC)
- DEC Alpha
- Intel 4004, 4040
- Intel 8080, 8085, Zilog Z80
- Intel 8086, 8088, 80186, 80188, 80286, 80386, 80486 (Intel x86 architecture)
- Intel Pentium, Pentium Pro, Celeron, Centrino, Pentium II, Pentium III, Xeon, Pentium 4, Pentium M (Intel x86, parents to the IA64 architecture with HP PA-RISC)
- Intel Itanium (IA-64 architecture)
- Intel i860, i960
- MIPS architecture
- Motorola 6800, MOS Technology 6502, Motorola 6809, WDC 65816
- Motorola 68000 family, ColdFire
- Motorola 88000 (parents of the PowerPC family, with POWER)
- IBM POWER (parents of the PowerPC family, with 88000)
- NSC 320xx
- OpenCores OpenRISC architecture
- PA-RISC family (HP, parents to the IA-64 architecture, with x86)
- PowerPC family, G3, G4, G5
- National Semiconductor SC/MP ("scamp")
- Signetics 2650
- SPARC, UltraSPARC, UltraSPARC II–IV
- SuperH family
- Transmeta's Crusoe and Efficeon
- INMOS Transputer
See also
- Addressing mode
- List of AMD microprocessors
- List of Intel microprocessors
- Microcontroller
- Computer architecture
- CPU design
- Digital signal processor
External links
da:Mikroprocessor
de:Mikroprozessor
es:microprocesador
fr:Microprocesseur
it:Microprocessore
la:Processor
ja:マイクロプロセッサ
sv:Mikroprocessor
