Difference between revisions of "Motorola MC68000"
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{{Infobox CPU | {{Infobox CPU | ||
| name = MC68000 | | name = MC68000 | ||
| + | | image = mc68000.jpg | ||
| + | | imgwidth = 200px | ||
| + | | caption = MC68000 in a Macintosh SE | ||
| manufacturer = [[Motorola]] | | manufacturer = [[Motorola]] | ||
| family = [[Motorola M68000 Family]] | | family = [[Motorola M68000 Family]] | ||
| architecture = 32-bit | | architecture = 32-bit | ||
| − | | address bus = | + | | address bus = 23-bit (16-bit word address) |
| data bus = 16-bit | | data bus = 16-bit | ||
| year introduced = 1979 | | year introduced = 1979 | ||
| Line 10: | Line 13: | ||
| clock speed = 4 MHz - 16.67 MHz | | clock speed = 4 MHz - 16.67 MHz | ||
}} | }} | ||
| + | The '''Motorola MC68000''' was the first member of the [[Motorola M68000 Family]] of [[VLSI]] [[microprocessor]]s. Although it was described by Motorola as a "16-bit microprocessor", it is generally considered to be a 32-bit [[architecture]]; it is probably more correct to describe it as a 16-bit '''''implementation''''' of a 32-bit architecture. | ||
| − | [[ | + | A major failing of the MC68000 was that it could not support [[virtual memory]]; not enough internal state was saved when a [[page fault]] occurred. Several computer makers worked around this by including two separate MC68000 chips; when a fault occurred, the first CPU was 'frozen', and a second fixed up the fault, then re-started the 'main' CPU. This issue was fixed with the successor chip, the [[MC68010]]. |
| − | + | {{semi-stub}} | |
| − | + | ==External links== | |
| + | |||
| + | * [http://www.bitsavers.org/components/motorola/68000/ 68000] - documentation at [[Bitsavers]] | ||
| + | ** [http://www.bitsavers.org/components/motorola/68000/MC68000_16-Bit_Microprocessor_Apr83.pdf MC68000 16-Bit Microprocessor] - data sheet | ||
| + | |||
| + | [[Category: Motorola Microprocessors]] | ||
Latest revision as of 17:37, 8 February 2024
| MC68000 | |
 MC68000 in a Macintosh SE | |
| Family: | Motorola M68000 Family |
|---|---|
| Architecture: | 32-bit |
| Manufacturer: | Motorola |
| Year Introduced: | 1979 |
| Address bus: | 23-bit (16-bit word address) |
| Data bus: | 16-bit |
| Number of registers: | 15 general 32-bit registers (8 data, 7 address) |
| Clock Speed: | 4 MHz - 16.67 MHz |
The Motorola MC68000 was the first member of the Motorola M68000 Family of VLSI microprocessors. Although it was described by Motorola as a "16-bit microprocessor", it is generally considered to be a 32-bit architecture; it is probably more correct to describe it as a 16-bit implementation of a 32-bit architecture.
A major failing of the MC68000 was that it could not support virtual memory; not enough internal state was saved when a page fault occurred. Several computer makers worked around this by including two separate MC68000 chips; when a fault occurred, the first CPU was 'frozen', and a second fixed up the fault, then re-started the 'main' CPU. This issue was fixed with the successor chip, the MC68010.
External links
- 68000 - documentation at Bitsavers
- MC68000 16-Bit Microprocessor - data sheet
