The 68LC040 is a low cost version of the
Motorola 68040 microprocessor with no
FPU. This makes it less expensive and draw less power. Although the CPU now fits into a feature chart more like the
68020, it continues to include the 040's
caches and
pipeline and is thus significantly faster than the 020.Some
mask revisions of the 68LC040 contained a
bug which prevents various software FPU
emulators from operating correctly. These revisions are typically found in 68LC040-based
Apple Macintosh computers. The bug triggers if an FPU
instruction which would trigger an
exception resides at the end of a page, and the next page is swapped out. In that case, the CPU will
page fault with the PC pointing at that FPU instruction, and then fail to trigger the FPU exception, leading to a variety of errors.
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