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AMX 68000 Target Guide
Memory Management Unit (MMU)
The MC68030, MC68040, MC68LC040 and MC68060 include a Memory Management
Unit (MMU) to support a demand-paged virtual memory environment. AMX does not
support the M68000 memory management unit.
If you are using AMX on the Motorola MC68000, MC68008, MC68010 or MC683xx
processors, this restriction does not apply. These processors do not implement the
M68000 memory management unit and allow direct access to the full 20, 24 or 32-bit
address space supported by the particular processor.
Your AMX application code and data must reside within the memory address ranges
allowed by the particular M68000 processor which you are using. The M68000 MMU, if
present, must be setup prior to launching AMX. In most cases, your boot ROM or C
startup code will configure the M68000 MMU for your specific hardware configuration
prior to entry to your
main() program.
Warning!
Do not enable the memory caches if the MMU has not been
initialized to provide proper cached access to memory.
Big or Little Endian
AMX 68000 adheres to the big endian model in which the most significant byte of a word
(long) is stored in the lowest byte address.
Be aware that AMX for other processors may be big or little endian. If you intend to port
your AMX application to other processors, then avoid using coding techniques which are
endian dependent.