68k
Encyclopedia
The Motorola
680x0/m68000/68000 is a family of 32-bit
CISC
microprocessor
s. During the 1980s and early 1990s, they were popular in personal computer
s and workstation
s and were the primary competitors of Intel's x86 microprocessors. They were most well known as the processors powering the early Apple Macintosh
, the Commodore Amiga
, the Sinclair QL
, the Atari ST
, SEGA Megadrive and several others. Although no modern desktop computers are based on the 68000, derivative processors are still widely used in embedded
applications.
68020
68030
:
68040
:
68060
:
calculators (the TI-89, TI-92, and Voyage 200 lines) to all of the members of the Palm Pilot series that run Palm OS 1.x to 4.x (OS 5.x is ARM
-based), 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 Sinclair QL
, the Atari ST
, and several others. The 68000 was also the processor of choice in the 1980s for Unix
workstation
s and servers
from firms such as Sun Microsystems
, NeXT
and Silicon Graphics
. There was a 68000 version of CP/M
, which received almost no notice, and almost no sales.
Additionally, and perhaps most significantly, the first several versions of Adobe's PostScript interpreters were 68000-based. A fast 68000 in the Apple LaserWriter
and LaserWriter Plus, also the LaserWriter IInt (all 300 dpi). A fast 68030 in later PostScript interpreters, including the standard resolution LaserWriter IIntx, IIf and IIg (also 300 dpi), the higher resolution LaserWriter Pro 600 series (usually 600 dpi, but limited to 300 dpi with minimum RAM installed) and the very high resolution Linotronic
imagesetters, the 200PS (1500+ dpi) and 300PS (2500+ dpi). Thereafter, Adobe generally preferred a RISC for its processor, as its competitors, with their PostScript clones, had already gone with RISCs, often an AMD 29000-series. The early 68000-based Adobe PostScript interpreters and their hardware were named for cold war
U.S. rockets and missiles: Atlas, Redstone, etc.
Today, these systems are either end-of-line (in the case of the Atari and Amiga), or are using different processors (in the case of Macintosh, Sun, and SGI). Since these platforms had their marketshare peak in the 1980s, 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 68000 processors.
The 68000 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 68000 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. Many arcade boards also used 68000 processors including boards from Capcom, SNK, and Sega.
Microcontroller
s derived from the 68000 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.
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 instruction set was much more "orthogonal" than those of many processors that came before (e.g., 8080) and after (e.g., x86). That is, it was typically possible to combine operations freely with operands, rather than being restricted to using certain addressing modes with certain instructions. This property made programming relatively easy for humans, and also made it easier to write code generators for compilers.
The 68000 instruction set
can be divided in the following broad categories:
There is also no revision of the 68060, as Motorola was in the process of shifting away from the 68000 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, likely with a superior FPU (pipelining was widely speculated upon on Usenet).
Motorola mainly used even numbers for major revisions to the CPU core such as 68000, 68020, 68040 and 68060. The 68010 was 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 licensed and somewhat slower version of the 16/32-bit 68000 with a basic DMA controller, I²C host and an on-chip serial port. 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.
architecture. Had Motorola decided to continue the 680x0 series, the next processor (68080) would likely have resembled Intel P6
architecture.
/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
.
VLIW processors — remains the only architecture used in IBM Compatible PCs
. Generation 1 68000 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 P5
Pentium line, but it was not nearly as widely used as its predecessors, since much of the old 68000 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
).
, ARM
, MIPS
, and SuperH
architectures, among others.
Motorola
Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...
680x0/m68000/68000 is a family of 32-bit
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
CISC
Complex instruction set computer
A complex instruction set computer , is a computer where single instructions can execute several low-level operations and/or are capable of multi-step operations or addressing modes within single instructions...
microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s. During the 1980s and early 1990s, they were popular in personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s and workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
s and were the primary competitors of Intel's x86 microprocessors. They were most well known as the processors powering the early Apple Macintosh
Macintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
, the Commodore Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
, the Sinclair QL
Sinclair QL
The Sinclair QL , was a personal computer launched by Sinclair Research in 1984, as the successor to the Sinclair ZX Spectrum...
, the Atari ST
Atari ST
The Atari ST is a home/personal computer that was released by Atari Corporation in 1985 and commercially available from that summer into the early 1990s. The "ST" officially stands for "Sixteen/Thirty-two", which referred to the Motorola 68000's 16-bit external bus and 32-bit internals...
, SEGA Megadrive and several others. Although no modern desktop computers are based on the 68000, derivative processors are still widely used in embedded
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
applications.
Family members
- Generation one (internally 16/32-bit, and produced with 8-, 16-, and 32-bit interfaces)
- Motorola 68000Motorola 68000The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
- Motorola 68EC000
- Motorola 68HC000
- Motorola 68008Motorola 68008The 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...
- Motorola 68010Motorola 68010The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982. In line with the Motorola 68000 naming convention, it is usually just referred to as the 010 ....
- Motorola 68012Motorola 68012The 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 2GB and an RMC pin was added, in order to help the design of multiprocessor systems with virtual memory...
- Motorola 68000
- Generation two (fully 32-bit32-bitThe range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....
)- Motorola 68020Motorola 68020The 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...
- Motorola 68EC020
- Motorola 68030Motorola 68030The Motorola 68030 is a 32-bit microprocessor in Motorola's 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 .The 68030 features on-chip...
- Motorola 68EC030
- Motorola 68020
- Generation three (pipelinedInstruction pipelineAn instruction pipeline is a technique used in the design of computers and other digital electronic devices to increase their instruction throughput ....
)- Motorola 68040Motorola 68040The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060. There was no 68050. In keeping with general Motorola naming, the 68040 is often referred to as simply the '040 ....
- Motorola 68EC040
- Motorola 68LC040
- Motorola 68040
- Generation four (superscalarSuperscalarA superscalar CPU architecture implements a form of parallelism called instruction level parallelism within a single processor. It therefore allows faster CPU throughput than would otherwise be possible at a given clock rate...
)- Motorola 68060Motorola 68060The Motorola 68060 is a 32-bit microprocessor from Motorola released in 1994. It is the successor to the Motorola 68040 and is the highest performing member of the 680x0 family. Two derivatives were produced, the 68LC060 and the 68EC060....
- Motorola 68EC060Motorola 68060The Motorola 68060 is a 32-bit microprocessor from Motorola released in 1994. It is the successor to the Motorola 68040 and is the highest performing member of the 680x0 family. Two derivatives were produced, the 68LC060 and the 68EC060....
- Motorola 68LC060Motorola 68060The Motorola 68060 is a 32-bit microprocessor from Motorola released in 1994. It is the successor to the Motorola 68040 and is the highest performing member of the 680x0 family. Two derivatives were produced, the 68LC060 and the 68EC060....
- Motorola 68060
- Others
- Freescale 683XX (CPU32 aka 68330, 68360 aka QUICCQUICCQUICC 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, PowerQUICC II+ and PowerQUICC III. Early chips used a separate RISC engine to control the serial interfaces....
) - Freescale ColdFireFreescale ColdFireThe Freescale ColdFire is a microprocessor that derives from the Motorola 68000 family architecture, manufactured for embedded systems development by Freescale Semiconductor .-Instruction set:...
- Freescale DragonBallFreescale DragonBallMotorola/Freescale Semiconductor's 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...
- Freescale 683XX (CPU32 aka 68330, 68360 aka QUICC
Improvement roadmap
68010Motorola 68010
The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982. In line with the Motorola 68000 naming convention, it is usually just referred to as the 010 ....
- Virtual memory support (restartable instructions).
- 'loop mode' for faster string and memory library primitives.
68020
Motorola 68020
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...
- 32-bit address & ALUArithmetic logic unitIn computing, an arithmetic logic unit is a digital circuit that performs arithmetic and logical operations.The ALU is a fundamental building block of the central processing unit of a computer, and even the simplest microprocessors contain one for purposes such as maintaining timers...
. - 3 stage pipeline.
- Instruction cacheCacheIn computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
of 256 bytes. - Unrestricted word and longword data access (see alignmentData structure alignmentData structure alignment is the way data is arranged and accessed in computer memory. It consists of two separate but related issues: data alignment and data structure padding. When a modern computer reads from or writes to a memory address, it will do this in word sized chunks...
). - 8 x multiprocessingMultiprocessingMultiprocessing is the use of two or more central processing units within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them...
capability. - Larger multiply (32×32 -> 64 bits) and divide (64÷32 -> 32 bits quotient and 32 bits remainder) instructions, and bit field manipulations.
- Addressing modes added scaled indexing and another level of indirection.
- Low cost, EC = 24-bit address.
68030
Motorola 68030
The Motorola 68030 is a 32-bit microprocessor in Motorola's 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 .The 68030 features on-chip...
:
- Split instruction and data cache of 256 bytes each
- On-chip MMUMemory management unitA memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...
(68851). - Low cost EC = No MMU.
68040
Motorola 68040
The Motorola 68040 is a microprocessor from Motorola, released in 1990. It is the successor to the 68030 and is followed by the 68060. There was no 68050. In keeping with general Motorola naming, the 68040 is often referred to as simply the '040 ....
:
- Instruction and data caches of 4 kilobytes each
- 6 stage pipeline.
- FPU lacks IEEE transcendental functionTranscendental functionA transcendental function is a function that does not satisfy a polynomial equation whose coefficients are themselves polynomials, in contrast to an algebraic function, which does satisfy such an equation...
s capability. - FPU emulation works with 2E71M and later chip revisions.
- Low cost LC = No FPU.
- Low cost EC = No FPU & MMU.
68060
Motorola 68060
The Motorola 68060 is a 32-bit microprocessor from Motorola released in 1994. It is the successor to the Motorola 68040 and is the highest performing member of the 680x0 family. Two derivatives were produced, the 68LC060 and the 68EC060....
:
- Instruction and data caches of 8 kilobytes each
- 10 stage pipeline.
- Two cycle integer multiplication unit.
- Branch predictionBranch predictorIn computer architecture, a branch predictor is a digital circuit that tries to guess which way a branch will go before this is known for sure. The purpose of the branch predictor is to improve the flow in the instruction pipeline...
. - Dual instruction pipeline.
- Instructions in the address generation unit (AGU) and thereby supply the result two cycles before the ALU.
- Low cost LC = No MMU.
- Low cost EC = No MMU & FPU.
Main uses
The 68000 line of processors has been used in a variety of systems, from modern high-end Texas InstrumentsTexas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
calculators (the TI-89, TI-92, and Voyage 200 lines) to all of the members of the Palm Pilot series that run Palm OS 1.x to 4.x (OS 5.x is ARM
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
-based), and even radiation hardened versions in the critical control systems of the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
. However, they became most well known as the processors powering desktop computers such as the Apple Macintosh
Macintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
, the Commodore Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
, the Sinclair QL
Sinclair QL
The Sinclair QL , was a personal computer launched by Sinclair Research in 1984, as the successor to the Sinclair ZX Spectrum...
, the Atari ST
Atari ST
The Atari ST is a home/personal computer that was released by Atari Corporation in 1985 and commercially available from that summer into the early 1990s. The "ST" officially stands for "Sixteen/Thirty-two", which referred to the Motorola 68000's 16-bit external bus and 32-bit internals...
, and several others. The 68000 was also the processor of choice in the 1980s for Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
s and servers
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
from firms such as Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, NeXT
NeXT
Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
and Silicon Graphics
Silicon Graphics
Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
. There was a 68000 version of CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
, which received almost no notice, and almost no sales.
Additionally, and perhaps most significantly, the first several versions of Adobe's PostScript interpreters were 68000-based. A fast 68000 in the Apple LaserWriter
LaserWriter
The LaserWriter was a laser printer with built-in PostScript interpreter introduced by Apple in 1985. It was one of the first laser printers available to the mass market...
and LaserWriter Plus, also the LaserWriter IInt (all 300 dpi). A fast 68030 in later PostScript interpreters, including the standard resolution LaserWriter IIntx, IIf and IIg (also 300 dpi), the higher resolution LaserWriter Pro 600 series (usually 600 dpi, but limited to 300 dpi with minimum RAM installed) and the very high resolution Linotronic
Linotronic
The Linotronic imagesetters are a now common type of high-quality printer, capable of printing at resolutions of up to 2540 dots per inch. The Linotronic allowed graphic artists to cheaply set type that exceeded the quality of many phototypesetting systems in use at the time...
imagesetters, the 200PS (1500+ dpi) and 300PS (2500+ dpi). Thereafter, Adobe generally preferred a RISC for its processor, as its competitors, with their PostScript clones, had already gone with RISCs, often an AMD 29000-series. The early 68000-based Adobe PostScript interpreters and their hardware were named for cold war
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
U.S. rockets and missiles: Atlas, Redstone, etc.
Today, these systems are either end-of-line (in the case of the Atari and Amiga), or are using different processors (in the case of Macintosh, Sun, and SGI). Since these platforms had their marketshare peak in the 1980s, their original manufacturers are unlikely to support an operating system for this hardware or are even out of business. However, the Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, NetBSD
NetBSD
NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
and OpenBSD
OpenBSD
OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...
operating systems still include support for 68000 processors.
The 68000 processors were also used in the Sega Mega Drive/Sega Genesis and SNK
SNK Playmore
SNK Playmore Corporation is a Japanese video game hardware and software company. SNK is an acronym of , which was SNK's original name. The company's legal and trading name became SNK in 1986....
Neo Geo
Neo Geo (console)
The is a cartridge-based arcade and home video game system released on July 1, 1991 by Japanese game company SNK. Being in the Fourth generation of Gaming, it was the first console in the former Neo Geo family, which only lived through the 1990s...
consoles as the main CPU. Other consoles such as the Sega Saturn
Sega Saturn
The is a 32-bit fifth-generation video game console that was first released by Sega on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe...
used the 68000 for audio processing and other I/O tasks, while the Atari Jaguar
Atari Jaguar
The Atari Jaguar is a video game console that was released by Atari Corporation in 1993. It was the last to be marketed under the Atari brand until the release of the Atari Flashback in 2004. It was designed to surpass the Mega Drive/Genesis, Super Nintendo Entertainment System, and the Panasonic...
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. Many arcade boards also used 68000 processors including boards from Capcom, SNK, and Sega.
Microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
s derived from the 68000 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-11PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
or VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
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 instruction set was much more "orthogonal" than those of many processors that came before (e.g., 8080) and after (e.g., x86). That is, it was typically possible to combine operations freely with operands, rather than being restricted to using certain addressing modes with certain instructions. This property made programming relatively easy for humans, and also made it easier to write code generators for compilers.
The 68000 instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
can be divided in the following broad categories:
- Load and store (Move.B, Move.W, Move.L)
- ArithmeticArithmeticArithmetic or arithmetics is the oldest and most elementary branch of mathematics, used by almost everyone, for tasks ranging from simple day-to-day counting to advanced science and business calculations. It involves the study of quantity, especially as the result of combining numbers...
(Add, Sub, Mul, Div) - Bit shiftingBitwise operationA bitwise operation operates on one or more bit patterns or binary numerals at the level of their individual bits. This is used directly at the digital hardware level as well as in microcode, machine code and certain kinds of high level languages...
(left or right, logical or arithmetical) - Bit rotation (ROR, ROL, ROXL, ROXR)
- Logic operations (And, Or, Not, EOr)
- Type conversion (byteByteThe byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
to word and vice versa) - Conditional and unconditional branches (Bra, BCS, BEq, BNE, BHI, BLO, BMI, BPL, etc.)
- SubroutineSubroutineIn computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....
invocation and return (BSR, RTS) - StackCall stackIn computer science, a call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, control stack, run-time stack, or machine stack, and is often shortened to just "the stack"...
management (pea / move x,(sp) / move (sp),x ) - Causing and responding to interruptInterruptIn computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....
s - Exception handlingException handlingException handling is a programming language construct or computer hardware mechanism designed to handle the occurrence of exceptions, special conditions that change the normal flow of program execution....
68050 and 68070
There was no 68050, though at one point it was a project within Motorola. Odd-numbered releases had always been reactions to issues raised within the previous even numbered part; hence, it was generally expected that the 68050 would have reduced the 68040's power consumption (and thus heat dissipation), improved exception handling in the FPU, used a smaller feature size and optimized the microcode in line with program use of instructions. Many of these optimizations were included with the 68060 and were part of its design goals. For any number of reasons, likely that the 68060 was in development, that the Intel 80486 wasn't progressing as quickly as Motorola assumed it would, and that 68060 was a demanding project, the 68050 was cancelled early in development.There is also no revision of the 68060, as Motorola was in the process of shifting away from the 68000 and 88k
88000
The 88000 is a RISC instruction set architecture developed by Motorola. The 88000 was Motorola's attempt at a home-grown RISC architecture, started in the 1980s. The 88000 arrived on the market some two years after the competing SPARC and MIPS...
processor lines into its new PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
business, so the 68070 was never developed. Had it been, it would have been a revised 68060, likely with a superior FPU (pipelining was widely speculated upon on Usenet).
Motorola mainly used even numbers for major revisions to the CPU core such as 68000, 68020, 68040 and 68060. The 68010 was 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 licensed and somewhat slower version of the 16/32-bit 68000 with a basic DMA controller, I²C host and an on-chip serial port. This 68070 was used as the main CPU in the Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
CD-i
CD-i
CD-i, or Compact Disc Interactive, is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N.V. CD-i also refers to the multimedia Compact Disc standard used by the CD-i console, also known as Green Book, which was developed by Philips and Sony...
. This CPU was, however, produced by Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
and not officially part of Motorola's 680x0 lineup.
Last generation
The 4th generation 68060 shared most of the features of the Intel P5Pentium compatible processor
A Pentium compatible processor is a 32-bit processor computer chip which supports the instructions in the IA-32 instruction set that were implemented by the Intel P5 Pentium processor family...
architecture. Had Motorola decided to continue the 680x0 series, the next processor (68080) would likely have resembled Intel P6
P6 (microarchitecture)
The P6 microarchitecture is the sixth generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is sometimes referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M...
architecture.
Other variants
After the mainline 68000 processors' demise, the 68000 family has been used to some extent in microcontrollerMicrocontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
/embedded microprocessor versions. These chips include the ones listed under "other" above, i.e. the CPU32 (aka 68330), the ColdFire
Freescale ColdFire
The Freescale ColdFire is a microprocessor that derives from the Motorola 68000 family architecture, manufactured for embedded systems development by Freescale Semiconductor .-Instruction set:...
, the QUICC
QUICC
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, PowerQUICC II+ and PowerQUICC III. Early chips used a separate RISC engine to control the serial interfaces....
and the DragonBall
Freescale DragonBall
Motorola/Freescale Semiconductor's 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...
.
Desktop
During the 1980s and early 1990s, when the 68000 was widely used in desktop computers, it mainly competed against Intel's x86 architecture, which to this day — other than a small minority of TransmetaTransmeta
Transmeta Corporation was a US-based corporation that licensed low power semiconductor intellectual property. Transmeta originally produced very long instruction word code morphing microprocessors, with a focus on reducing power consumption in electronic devices. It was founded in 1995 by Bob...
VLIW processors — remains the only architecture used in IBM Compatible PCs
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
. Generation 1 68000 CPUs primarily competed against the 16-bit 8086
Intel 8086
The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
/8088
Intel 8088
The Intel 8088 microprocessor was a variant of the Intel 8086 and was introduced on July 1, 1979. It had an 8-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range were unchanged, however...
and 80286
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
. Generation 2 competed against the 80386 (the first 32-bit x86 processor), and generation 3 against the 80486. The fourth generation competed with the P5
P5 (microarchitecture)
The original Pentium microprocessor was introduced on March 22, 1993. Its microarchitecture, deemed P5, was Intel's fifth-generation and first superscalar x86 microarchitecture. As a direct extension of the 80486 architecture, it included dual integer pipelines, a faster FPU, wider data bus,...
Pentium line, but it was not nearly as widely used as its predecessors, since much of the old 68000 marketplace was either defunct or nearly so (as was the case with Atari, Amiga and NeXT), or converting to newer architectures (PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
for the Macintosh
Macintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
, SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
for Sun
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, and MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
for SGI
Silicon Graphics
Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
).
Embedded
There are dozens of processor architectures that are currently successful in embedded systems. Some are microcontrollers which are much simpler, smaller, and cheaper than the 68000, while others are relatively sophisticated and capable of running complex software. Embedded versions of the 68000 often compete with processors derived from the PowerPCPowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
, ARM
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
, MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
, and SuperH
SuperH
SuperH is a 32-bit reduced instruction set computer instruction set architecture developed by Hitachi. It is implemented by microcontrollers and microprocessors for embedded systems....
architectures, among others.