Preface
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The Real Time Executive for Multiprocessor Systems (RTEMS) is designed to be portable across multiple processor architectures.  However, the nature of real-time systems makes it essential that the application designer understand certain processor dependent implementation details.  These processor dependencies include calling convention, board support package issues, interrupt processing, exact RTEMS memory requirements, performance data, header files, and the assembly language interface to the executive.

This document discusses the Motorola MC68xxx architecture dependencies in this port of RTEMS.  The MC68xxx family has a wide variety of CPU models within it.  The part numbers for these models are generally divided into MC680xx and MC683xx.  The MC680xx models are more general purpose processors with no integrated peripherals.  The MC683xx models, on the other hand, are more specialized and have a variety of peripherals on chip including sophisticated timers and serial communications controllers.

It is highly recommended that the Motorola MC68xxx RTEMS application developer obtain and become familiar with the documentation for the processor being used as well as the documentation for the family as a whole.

Architecture Documents
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For information on the Motorola MC68xxx architecture, refer to the following documents available from Motorola (http//www.moto.com/):

  * M68000 Family Reference, Motorola, FR68K/D.

MODEL SPECIFIC DOCUMENTS
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For information on specific processor models and their associated coprocessors, refer to the following documents:

  * MC68020 User's Manual, Motorola, MC68020UM/AD.

  * MC68881/MC68882 Floating-Point Coprocessor User's Manual, Motorola, MC68881UM/AD.