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Information about 68k

The Motorola 680x0/m68k/68k/68K family of CISC microprocessor CPU chips were 32-bit from the start, and were the primary competition for the Intel x86 family of chips in personal computers of the 1980s and early 1990s. Although no modern desktop computers are based on the 68k, derivative processors are still widely used in embedded applications.

Family members

Main uses

The 68k line of processors has been used in a variety of systems, from modern high-end Texas Instruments calculators (the TI-89, TI-92, and Voyage 200 lines) to older members of the palm pilot series, and even radiation hardened versions in the critical control systems of the Space Shuttle. However, they became most well-known as the processors powering desktop computers such as the Apple Macintosh, the Commodore Amiga, the Atari ST, and several others. The 68k was also the processor of choice in the 1980s for Unix workstations and servers from companies such as Sun Microsystems, NeXT and SGI.

Today, these systems are either end-of-line (in the case of the Atari), or are using different processors (as is the case for Amiga, Macintosh, Sun, and SGI). Since these platforms are now more than a decade old, their original manufacturers are unlikely to support an operating system for this hardware or are even out of business. However, the Linux, NetBSD and OpenBSD operating systems still include support for 68k processors.

The 68k processors were also used in the Sega Mega Drive/Sega Genesis and SNK Neo Geo consoles as the main CPU. Other consoles such as the Sega Saturn used the 68k for audio processing and other I/O tasks, while the Atari Jaguar included a 68000 which was intended for basic system control and input processing, but due to the Jaguar's unusual assortment of heterogeneous processors was also frequently used for running game logic.

Microcontrollers derived from the 68k family have been used in a huge variety of applications. For example, CPU32 and ColdFire microcontrollers have been manufactured in the millions as automotive engine controllers.

Architecture

People who are familiar with the PDP-11 or VAX usually feel comfortable with the 68000. With the exception of the split of general purpose registers into specialized data and address registers, the 68000 architecture is in many ways a 32-bit PDP-11.

The 68k instruction set can be divided in the following broad categories:

68050 and 68070

Note that there is no 68050; this is because the design that was destined to be the 68050 was eventually released as a version of the 68040. There is also no revision of the 68060, as Motorola was in the process of shifting away from the 68k and 88k processor lines into its new PowerPC business, so the 68070 was never developed. Had it been, it would have been a revised 68060.

Motorola mainly used even numbers for major revisions to the CPU core such as 68000, 68020, 68040 and 68060. The 68010 vas a revised version of the 68000 with minor modifications to the core, and likewise the 68030 was a revised 68020 with some more powerful features, none of them significant enough to classify as a major upgrade to the core.

There was a CPU with the 68070 designation, which was a microcontroller version of the 16/32-bit 68000. This 68070 was used as the main CPU in the Philips CD-i. This CPU was, however, produced by Philips and not officially part of Motorola's 680x0 lineup.

Last generation

The 4th generation 68060 shared most of the features of the Intel P5 architecture. Had Motorola decided to continue the 680x0 series, the next processor (68080) would likely have resembled Intel's P6 architecture.

Other variants

After the mainline 68k processors' demise, the 68k family has been used to some extent in microcontroller/embedded microprocessor versions. These chips include the ones listed under "other" above, i.e. the CPU32 (aka 68330), the ColdFire, the QUICC and the DragonBall.

Competitors

Desktop

During the 80s and early 90s, when the 68k was widely used in desktop computers, it mainly competed against Intel's x86 architecture, which to this day remains the only architecture used in IBM Compatible PCs. Generation 1 68k CPUs primarily competed against the 16-bit 8086/8088 and 80286. Generation 2 competed against the 80386 (the first 32-bit x86 processor), and generation 3 against the 80486. The fourth generation competed with the original Pentium line, but it was not nearly as widely used as its predecessors, since much of the old 68k marketplace was either defunct or nearly-so (as was the case with Atari, Amiga and NeXT), or converting to newer architectures (PowerPC for the Macintosh, SPARC for Sun, and MIPS for SGI).

Embedded

There are literally dozens of processor architectures that are currently successful in embedded systems. Some are microcontrollers which are much simpler, smaller, and cheaper than the 68k, while others are relatively sophisticated and capable of running complex software. Embedded versions of the 68k often compete with processors derived from the PowerPC, ARM, MIPS, and SuperH architectures, among others.

Bibliography

  • Howe, Dennis, ed. (1983). Free On-Line Dictionary of Computing. Imperial College, London. http://foldoc.org. Retrieved September 4, 2007.
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Motorola/Freescale processors
The 6800 family6809 (see also: Hitachi 6309)
68000 family68000 68008 68010 68012 68020 68030 68040 68060 ColdFire DragonBall
Low-cost variants68EC000 68EC020 68EC030 68EC040 68LC040
Pre-PowerPC RISC88000
Floating-point coprocessors68881, 68882
PowerPC familyPPC e200 PPC 603e/e300 PPC 75x PPC e500 PPC 74xx/e600 PowerQUICC family
Motorola Inc.

Public (NYSE: MOT )
Founded 1928
Headquarters Schaumburg, Illinois, USA

Key people Edward Zander, CEO & Chairman
Industry Telecommunications
Products Embedded systems
Microprocessors
Mobile phones
Two-Way radios
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complex instruction set computer (CISC pronouced sisk) is a microprocessor instruction set architecture (ISA) in which each instruction can execute several low-level operations, such as a load from memory, an arithmetic operation, and a memory store, all in a single
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Microprocessor

Die of an Intel 80486DX2 microprocessor (actual size: 12×6.75 mm) in its packaging
Date Invented: Late 1960s/Early 1970s (see article for explanation)

Connects to:
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central processing unit (CPU), or sometimes simply processor, is the component in a digital computer capable of executing a program.(Knott 1974) It interprets computer program instructions and processes data.
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In computer architecture, 32-bit integers, memory addresses, or other data units are those that are at most 32 bits (4 octets) wide. Also, 32-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
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Intel Corporation

Public (NASDAQ:  INTC , SEHK: 4335 )
Founded 1968 1
Headquarters Santa Clara, California
 United States

Key people Paul S.
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The generic term x86 refers to the "CISC" type instruction set of the most commercially successful CPU architecture[1] in the history of personal computing, used in processors from Intel, AMD, VIA, and others.
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personal computer (PC) is a computer whose original sales price, size, and capabilities make it useful for individuals.

It is unknown who coined the phrase with the intent of a small affordable computing device but John W.
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An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions.[1] It is usually embedded as part of a complete device including hardware and mechanical parts.
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The Motorola 68000 is a CISC microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor Products Sector). As the first member of the successful 32-bit m68k family of microprocessors, it is generally software forward compatible with the
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The 68EC000 is a microprocessor from Motorola. It is a low-cost version of the Motorola 68000, designed for embedded controller applications. The 68EC000 can have either a 8-bit or 16-bit data bus, switchable at reset.
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The Motorola 68008 is an 8/16/32-bit microprocessor made by Motorola. It is a version of the Motorola 68000 with an 8-bit external data bus, as well as a smaller address bus.

The original 68000 had a 24-bit address bus and a 16-bit data bus.
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The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982.[1] In common with the Motorola 68000 naming convention, it is usually just referred to as the 010 (pronounced oh-one-oh).
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The Motorola MC68012 processor is a 16/32-bit microprocessor from the early 1980s. It is an 84-pin PGA version of the Motorola MC68010. The memory space was extended to 2GiB (causing the same issue as the 68020 for any programs using the high byte of an address except those only
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In computer architecture, 32-bit integers, memory addresses, or other data units are those that are at most 32 bits (4 octets) wide. Also, 32-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
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The Motorola 68020 is a 32-bit microprocessor from Motorola, released in 1984. It is the successor to the Motorola 68010 and is succeeded by the Motorola 68030.

Description

The 68020 (usually just referred to as the '020, pronounced oh-two-oh or oh-twenty
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The 68EC020 is a microprocessor from Motorola. It is a lower cost version of the Motorola 68020, the difference between the two being that the 68EC020 only has a 24-bit address bus, rather than the 32-bit address bus of the full 68020, and thus is only able to address 16 MB of RAM.
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The Motorola 68030 is a 32-bit microprocessor in Motorola's 68000 family. Released in 1987, the 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040.
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The 68EC030 is a microprocessor from Motorola. It is a lower cost version of the Motorola 68030, the difference between the two being that the 68EC030 does not have an on-chip memory management unit.
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instruction pipeline is a technique used in the design of computers and other digital electronic devices to increase their instruction throughput (the number of instructions that can be executed in a unit of time).
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The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060 (the 68050 project having been abandoned.
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The 68EC040 is a version of the Motorola 68040 microprocessor intended for embedded controllers. It differs from the 68040 in that it has no FPU or MMU. This makes it less expensive and draw less power.
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The 68LC040 is a low cost version of the Motorola 68040 microprocessor with no FPU. This makes it less expensive and draw less power. Although the CPU now fits into a feature chart more like the 68020, it continues to include the 040's caches and pipeline and is thus
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superscalar CPU architecture implements a form of parallelism called Instruction-level parallelism within a single processor. It thereby allows faster CPU throughput than would otherwise be possible at the same clock rate.
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The Motorola 68060 is a 32-bit microprocessor from Motorola, released in 1994, and is the successor to the Motorola 68040. The 68060 is the highest performance 680x0 family processor available.
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The Freescale 683XX (formerly Motorola 683XX) is a family of compatible microcontrollers that use a Freescale 68000-based CPU core. The family was designed using a Hardware Description Language, making the parts synthesizable, and amenable to improved fabrication processes,
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QUICC is the abbreviation of QUad Integrated Communications Controller. The original QUICC was the 68k-based Motorola 68360. It was followed by the PowerPC-based PowerQUICC, PowerQUICC II, and PowerQUICC III.
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The Freescale ColdFire is a 68k architecture microprocessor manufactured for embedded systems development by Freescale Semiconductor (formerly the semiconductor sector of Motorola).
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DragonBall, or MC68328, is a microcontroller design based on the famous 68000 core, but implemented as an all-in-one low-power solution for handheld computer use. It was designed by Motorola in Hong Kong, China.
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Texas Instruments

Public (NYSE:  TXN )
Founded 1930 (as GSI), 1951 (as TI)[1]
Headquarters Dallas, Texas, USA

Key people Tom Engibous, Chairman
Rich Templeton, President & CEO
Kevin March, CFO
Brian Bonner, CIO
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