Motorola 68030 Explained

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. In keeping with general Motorola naming, this CPU is often referred to as the 030 (pronounced oh-thirty).

The 68030 features an on-chip split instruction and data cache of 256 bytes each. It also has an on-chip memory management unit. The 68881 and the faster 68882 FPU (floating point unit) chips could be used with the 68030. A lower cost version of the 68030, the Motorola 68EC030, was also released, lacking the on-chip MMU. It was commonly available in both 132 pin QFP and 128 pin PGA packages, but the poorer thermal characteristics of the QFP package limited it to 33MHz and below, the 40MHz and 50MHz only usually being available as PGA, though there was a small supply of QFP packaged EC variants.

As a microarchitecture, the 68030 is basically a 68020 core with an additional data cache and a process shrink. Motorola used the process shrink to allow them to pack more hardware on the die, in this case it was the MMU, a 68851 compatible. The integration of the MMU made it more cost-effective than the 68020. Per clock, the 68030 did not differentiate itself in performance from the 68020 that it was derived from. The finer manufacturing process, however, allowed Motorola to scale the processor to 50 MHz. The EC variety topped out at 40 MHz.

The 68030 was used in many models of the Apple Macintosh II and Commodore Amiga series of personal computers, NeXT Cube, Sun Microsystems Sun 3/80 desktop workstation, later Alpha Microsystems multiuser systems, and some descendants of the Atari ST line such as the Atari TT and the Atari Falcon. Other uses were Unix workstations and Laser printers.

Cisco Systems' 2500 Series Router, a small-to-medium enterprise computer internetworking appliance, claims in software to utilize the 68030, although it is in fact an 68EC030 inside the router.

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