The 68000 has 32-bit registers but only a 16-bit ALU and Intel's contemporary processors that make programming them unpleasant. That means that a single directly accessed array or structure can be larger than 64KB in size. Addresses are computed as 32 bit, but the top 8 bits are cut to fit the address bus into a 64-pin package (address and data The 68000 has sixteen 32-bit registers, split into data and address registers. One address register is reserved for the for any function except direct addressing. Only address registers can be used as the source of an address, but data registers can provide the offset from an address. Like the Zilog Z8000, the 68000 features a supervisor and 32 bits internally, making it faster and eliminating forced segmentations. Like many other CPUs of its generation, it can fetch the next instruction during execution (2 stage pipeline). used in most of Sega's early arcade machines, and in the Variants of the 68000 include the 68HC000 (a low-power HCMOS implementation) and the 68008 (an eight-bit data bus version ["The 68000: Principles and Programming", Leo Scanlon, 1981]. (2003-07-11)
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