Year |
Microprocessor | Points of Note |
|---|---|---|
1971 |
Intel 4004 | 4-bit central processing unit (CPU), designed for a calculator, and it is widely considered to be the world's first commercial single-chip microprocessor. It processed data in 4 bits, but its instructions were 8 bits long. Program and Data memory were separate, 1K data memory and a 12-bit PC for 4K program memory (in the form of a 4 level stack, used for CALL and RET instructions). There were also sixteen 4-bit (or eight 8-bit) general purpose registers. The 4004 had 46 instructions, using only 2,300 transistors (employing 10μ silicon-gate PMOS technology) in a 16-pin DIP. It had an operating speed of 740kHz (eight clock cycles per CPU cycle of 10.8 microseconds) and could execute approximately 60,000 instructions per second. |
1972 |
Intel 8008 | 8008 was twice as powerful as the 4004. The early versions of the 8008 ran at 0.5 MHz, which was a little slower (in terms of instructions per second) that the 4004. However the 8008 processed data eight bits at a time and could access significantly more RAM giving it more than 3 times the true processing power of the earlier 4-bit chips. Later versions of the 8008 increased to 0.8 MHz. |
1974 |
Intel 8080 | 8080 CPU was released to run at 2 MHz. Its 40 pin DIP packaging allowed it to provide a 16-bit address bus and an 8-bit data bus (utilising Von-Neumann architecture where instructions and data share the same space), permitting easy access to 64 kilobytes of memory. The processor had seven 8-bit registers, six of which could be combined into three 16-bit register pairs. It also had the 8-bit accumulator, the 16-bit stack pointer to memory (replacing the 8008's internal stack), and a 16-bit program counter. It also had several I/O ports - 256 of them, so I/O devices could be hooked up without taking away or interfering with the addressing space, and a signal pin that allowed the stack to occupy a separate bank of memory. The 8080 was used in the Altair 8800, the first widely-known personal computer. Another thing about the 8080 was its separate I/O map. This meant that to perform byte-wide input/output to hardware, special instructions were used: IN to input from byte-wide input ports, OUT to output to byte-wide output ports. Access to memory involved access to a different memory map using typically the MOV instruction. |
| Intel Evolution | In the case of the Intel range of microprocessors, the 8080 evolved into the 8085 (also 8 bit like the 8080), then the third generation 16 bit 8086 microprocessor which, in its 8088 pseudo 16 bit form, was used in the first IBM PCs. The 8088 was an 8086 but with only an 8 bit data bus. This made it easier to interface to the common 8 bit peripheral devices available at the time. In time this was followed by the 80186, the 80286, the 800386 ( a 32 bit processor), and 80486, leading to the Pentium range of microprocessors (64 bit processors) available today. The 80x86 and Pentium processors have all been designed for use in personal computer type applications and have large memory maps. In due course the Intel 8080 core processor was used for a range of microcontrollers (8048 and 8051 to name but two). The 8051 microcontroller survives today but is now manufactured by Philips. Intel has gone on to develop a range of other microcontrollers that are more complex than the basic original devices (see http://developer.intel.com for more details). | |
1974 |
TI - TMS 1000 | The 4-bit TMS 1000 was the first microprocessor to include enough RAM, and space for a program ROM, and I/O support on a single chip to allow it to operate without multiple external support chips, effectively creating the first microcontroller. It also featured an innovative feature to add custom instructions to the CPU. It included a 4-bit accumulator, 4-bit Y register and 2 or 3-bit X register, which combined to create a 6 or 7 bit index register for the 64 or 128 nibbles of on-board RAM. A 1-bit status register was used for various purposes in different contexts. By using the 6-bit PC with the 4 bit page register (+ optional 1 bit bank register) it could address up to 1KB (or 2KB) of ROM from these 10 (or 11) address bits. |
1974 |
Motorola 6800 | The 6800 was an 8 bit processor with about the same processing power as that of the 8080. It was available with supporting components including a 128-by-8-bit random access memory (RAM), a 1024-by-8-bit read-only memory (ROM), a peripheral interface adapter (PIA), and a single-chip 0-600 bps modem. All these components were TTL compatible, MOS n-channel, silicon gate devices, and only a single, 5.0-volt supply was needed for all the devices. The system used a single bus organization that allows memory and interface devices to share the same address space. The 6800 had a 16-bit address bus and could address up to 64 KB of memory. From common registers the CPU had only two accumulators and one index register. The 6800 didn't have I/O instructions and therefore 6800-based systems had to use memory-mapped I/O for input/output capabilities. The 6800 used what is called "Memory Mapped I/O" which means that both memory and byte-wide input/output share the same memory map. Motorola 6800 core processor was also used for a range of microcontrollers (6805, 6808, 6811 which survive to this day). |
1975 |
AMD Am2901 | Popular 4-bit-slice processor, which had sixteen 4-bit registers and a 4-bit ALU. They could be used for a modular design, where several processors could be combined to produce a larger system. It also contained the first integrated maths coprocessor. |
1976 |
TMS 9900 - Texas Instruments | One of the first 16-bit microprocessors, featured a 15-bit address bus and two internal 16 bit registers. It had good interrupt handling features and very good instruction set. Serial I/O was available through address lines. In typical comparisons with the Intel 8086, the TMS9900 had smaller and faster programs. The only disadvantage was the small address space and need for fast RAM. One unique feature, though, was that all user registers were actually kept in memory - this included stack pointers and the program counter. A single workspace register pointed to the 16 register set in RAM, so when a subroutine was entered or an interrupt was processed, only the single workspace register had to be changed. Despite the very poor support from Texas Instruments, the TMS 9900 had the potential at one point to surpass the 8086 in popularity. (TI also produced an embedded version, the TMS 9940.) |
| Motorola Evolution | The Motorola range of microprocessors also evolved with the 6800 being replaced by the 6809 (8 bit), then the 68000 (16 bit), the 68010, 68020, and 68030 used in many workstations and of course the Apple MAC range of personal computers. | |
1976 |
Zilog Z-80 | The Zilog Z-80 was a vastly improved 8080, as it was designed by ex-Intel engineers. It used 8 bit data and 16 bit addressing, and could execute all of the 8080 op-codes, plus 80 more instructions. The register set was doubled, with the ability to switch between two banks of data registers, which allowed for a faster operating system. Clock speeds ranged from the original Z-80 2.5MHz to the Z80-H (later called Z80-C) at 8MHz, and later a CMOS version at 10MHz. |
1977 |
Motorola 6809 | Enhanced version of the 6800. It had two 8-bit accumulators and could combine them into a single 16 bit register. It also featured two index registers and two stack pointers, which allowed for some very advanced addressing modes. The 6809 was source compatible with the 6800, yet operated with fewer instructions. Some instructions were replaced by more general ones which the assembler would translate, and some were even replaced by addressing modes. While the 6800 and 6809 both had a fast 8 bit mode to address the first 256 bytes of RAM, the 6809 had an 8 bit ‘Direct Page’ register to locate this fast address page anywhere in the 64K address space. Other features included the use of one of the first multiplication instructions of the time, 16 bit arithmetic, and a special fast interrupt. In general the device was highly optimized, proving to be almost five times the speed of the 6800 series CPU. |
1978 |
Intel 8086 | It was a 40 pin DIP device, which had a CPU range from 4.77MHz to 10MHz. It had a 20 bit address bus so it could access 1MB memory, had a 16 bit data bus and could access 16 bit data in one operation. It had eight 16-bit registers (including the stack pointer) and four of these could also be accessed as eight 8-bit registers. 8086 instructions varied from 1 to 6 bytes and the processor featured eight 16-bit registers including the stack pointer. The 8086 also featured 64K 8-bit I/O ports (or 32K 16 bit), and fixed vectored interrupts. The chip had around 29,000 transistors. This gave rise to the x86 architecture. |
| PIC 16x/17x | (the first 16-bit microcontrollers are probably National Semiconductor IMP-16 or AMD 2901 bit slice processors in 16 bit configuration). | |
1979 |
Zilog 8000 | The Z8000 was a 16-bit microprocessor (not Z80 compatible), including builtin DRAM refresh circuitry, and some versions had 7-bit segment registers that extended the address space to 8 mebibytes. The register set consisted of 16 16-bit registers, and there were instructions that could use them as 8-bit, 16-bit, 32-bit, and 64-bit registers. The register set was completely orthogonal, with register 15 conventionally designated as stack pointer, and register 14 for stack segment. There was both a user mode and a supervisor mode. Overall the Z8000 was not especially fast and had some bugs, and in the end it was overshadowed by the x86 family. |
1979 |
Motorola 68000 | Motorola 68000 (Sept. 1979). 32-bit internal architecture, with an external 16-bit data bus, and a 24-bit address bus. It contained 16 32-bit registers (8 for data, and 8 for address) and did not feature segmented addressing. The Motorola 68000 is a 32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor Products Sector). As the first member of the successful m68k family of microprocessors, its software is generally forward compatible with the rest of the line. After twenty-seven years in production, the 68000 architecture remains a popular choice for new designs. The 68000 grew out of the MACSS (Motorola Advanced Computer System on Silicon) project, begun in 1976. One of the early decisions made was to develop a new "no compromise" architecture that paid little attention to backward compatibility. This was a gamble because it would mean adopters of the chip would have to learn the new system entirely from scratch. In the end, the only concession to backward compatibility was a hardware one: the 68k could interface to existing 6800 peripheral devices, but could not run 6800 code. However, the designers built in a tremendous amount of forward compatibility, which paid off once 68k expertise had been gained by end users. For instance, the CPU registers were 32-bits wide, though address and data buses outside the CPU were initially narrower. In contrast the Intel 8086/8088 were 16-bits wide internally. The MACSS team drew heavily on the influence of minicomputer processor design, such as the PDP-11 and VAX systems. The instruction set was developed with software development in mind more than hardware limitations; the idea was that developers familiar with these older systems would be comfortable programming the new microprocessor. As the new design reached production a trade name had to be selected. The name "68000" was selected largely to provide some naming and marketing continuity with the earlier 6800, although there was little in common between the two designs. The name was justified by claiming the chip featured about 68,000 transistors, but in fact the count was closer to 70,000. At the time, there was fierce competition among several of the then established manufacturers of 8-bit processors to bring out 16-bit designs. National Semiconductor had been first with its IMP-16 and PACE processors in 1973-1975, but these had issues with speed caused by their hole-doped MOS architecture. Texas Instruments was next, with its TMS9900, but its CPU was not widely accepted. Next came Intel with the Intel 8086/8088 in 1977/78. However, Motorola marketing stressed the (true) point that the 68000 was a much more complete 16-bit design than the others. This was reflected in its complexity. The transistor cell count, which was then a fairly direct measure of power in that era, was more than twice that of the 29,000 of the 8086. The simplest 68000 instructions took four clock cycles, but the most complex ones required many more. An 8 MHz 68000 had an average performance of roughly 1 MIPS. On average, the 68000's instructions in typical program code did more work per instruction than competing Intel processors, which meant that 68000 designs both needed less RAM to store machine code and were faster.[citation needed] Additionally, the 68000 offered a "flat" 24-bit addressing system supporting up to 16 MiB of memory; at the time, this was a very large memory space. Intel chips instead used a segmented system which was much more difficult to program. Only in 1986 the 80386 allowed flat addressing. Thus the 68000 was easier to learn and work with, which led many engineers to prefer it to the Intel designs.The original MC68000 was fabricated using an HMOS process with a 3.5-micron feature size. Initial engineering samples were released in late 1979. Production chips were available by 1980, with initial speed grades of 4, 6, and 8 MHz. 10 MHz chips became available during 1981, and 12.5 MHz chips during 1982. The 16.67 MHz "12F" version of the MC68000, the fastest version of the original HMOS chip, was not produced until the late 1980s. |
1979 |
Intel 8080 | Intel 8088, was essentially the same as the 8086 chip, but with an external 8-bit data bus (allowing the use of cheaper and fewer supporting logic chips), and is notable as the processor used in the original IBM PC. |
1979 |
Motorola announce a 16-bit 68000, which would be used in the Apple Macintosh launched in 1984. | |
1980 |
Intel 8051 | The Intel 8051 is a Harvard architecture single chip 8-bit microcontroller (µC) with on-board EPROM memory (128 bytes of data stored on-chip and code stored off chip), that was developed for use in embedded systems. It was extremely popular in the 1980s and early 1990s. Today it has largely been superseded by a vast range of enhanced devices with 8051-compatible processor cores that are manufactured by more than 20 independent manufacturers including Analog Devices, Atmel, Hynix, Infineon Technologies, Intel, ISSI, Maxim (Dallas) IC, Micronas, NXP (formerly Philips Semiconductor), Oki, SST, Winbond, Silicon Laboratories, Texas Instruments and Cypress Semiconductor. Intel's original 8051 family was developed using NMOS technology, but later versions, identified by a letter "C" in their name, e.g. 80C51, used CMOS technology and were less power-hungry than their NMOS predecessors - this made them eminently more suitable for battery-powered applications. |
1982 |
MC68008 | To support low-cost systems with smaller memory sizes, Motorola introduced the MC68008 - it was a 68000 with an 8-bit data bus and a smaller (20 bits) address bus. (The 68012 later brought a 32 bit address bus.) |
1982 |
Motorola bring out the 68010 and the 6805 (a microcontroller based on the 6800). Intel bring out the 16-bit 80286 for the IBM PC ATand compatible computers. It has critical weaknesses, most notably in virtual memory support. The newest 'killer' application software, Microsoft Windows, needs a more powerful processor. IBMs service to the computer industry was to make the PC 'open', this meant clone makers could compete with IBM-compatible PCs. New companies such as Compaq and Dell (both from Texas) fare well, as do South Korea's Leading Edge and Taiwan's Acer who produce PCs with AT performance at half the price. IBM can't keep up. Intel bring out 16-bit microcontrollers, the 8096, 80186 and 80188. |
|
1984 |
National Semiconductor 32032 | National Semiconductor 32032. Similar to 68000. The first chip in the series was originally called 16032, later renamed 32016 to emphasize its 32-bit internals. It became available in the late 1970s, and may have been the first 32-bit chip to reach mass production and sale (at least according to National Semiconductor marketing).The original 32016 had a 16-bit external databus, a 24-bit external address bus, and a full 32-bit instruction set. It also included a coprocessor interface which allows coprocessors such as FPUs and MMUs to be attached as peers to the main processor.The instruction set was extremely complex but mostly regular, with a large set of addressing modes. It was somewhat similar in spirit to (but not compatible with) the popular DEC VAX minicomputer instruction set. The 32016 was also very similar to the Motorola 68000, which also used 32-bit internals with a 16-bit data bus and 24-bit address bus.The 32032 was introduced in 1984. It was almost completely compatible, but featured a 32-bit data bus (although keeping the 24-bit address bus) for somewhat faster performance. There was also a 32008, which was a 32016 with a data bus cut down to 8-bits wide for low cost applications. It was philosophically similar to the MC68008, and equally unpopular. Both the 32016 and the 32032 were notoriously unreliable. |
1984 |
68020 | Motorola bring out the 68020, a CMOS 32-bit microprocessor with 200,000 transistors. |
1985 |
Intel announce the 80386 a 32-bit microprocessor, of 275,000 transistors. It was the world's best performing processor at this time. | |
1986 |
Compaq are the first company to bring out a 386 PC. IBM's 386 PC, the PS/2, does not come out for another year. However, IBM remain the top PC seller, only topped by Compaq in 1994. | |
1987 |
Zilog bring out the Z280, a 16-bit version of the 8-bit Z80. Zilog's marketing has improved; its products are cheap ("less than the price of a Big Mac" their adverts proclaim). Zilog identify a niche market in Z80 support, recognising that many engineers prefer the Z80 because they used them in college. | |
1989 |
Intel bring out a bus-reduced 32-bit, 16-bit bus 80386SX as an inexpensive way to lure customers into the 386 market. In April, Intel announce the $950 80486. A 32-bit, 1.2 million transistor device with a maths coprocessor and memory management. It is the first microprocessor that can properly drive Microsoft's Windows software. However, there is a hitch. In October, Intel announce a 486 defect and replace purchased chips. The market is understanding …. this time. | |
1990 |
386 computers are selling like hot cakes. Intel cannot keep up with the demand and has to ration its chips for 6 months. | |
1991 |
Intel launch the 'Intel Inside' labelling campaign. | |
1992 |
The 32-bit (64-bit bus) PowerPC 601 is announced. It is the result of a joint venture between Motorola, IBM and Apple. It has 2.8 million transistors. Apple use it in the PowerMac and PowerPCs eventually follow (IBMs PowerPC is delayed until 1995). | |
1993 |
Intel introduce the 3 million transistor, 32-bit, 64-bit bus, "Pentium" processor. It has five times the power of the 486 for the same price. |
- This page is meant solely for useful reference and interest and has been gathered from numerous sources - it is not meant as a definitive list. If you feel strongly enough that you wish to suggest an amendment or addition, then please e-mail the University of Bolton course tutors.
[link to a list of current microcontroller manufacturers]
Updated 01.05.07 ML
Powered by Google
Site Map