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 SPARC architecture dependencies in this port of RTEMS.  Currently, only implementations of SPARC Version 7 are supported by RTEMS.

It is highly recommended that the SPARC RTEMS application developer obtain and become familiar with the documentation for the processor being used as well as the specification for the revision of the SPARC architecture which corresponds to that processor.

SPARC Architecture Documents
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For information on the SPARC architecture, refer to the following documents available from SPARC International, Inc. (http://www.sparc.com):

  * SPARC Standard Version 7.

  * SPARC Standard Version 8.

  * SPARC Standard Version 9.

ERC32 Specific Information
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The European Space Agency's ERC32 is a three chip computing core implementing a SPARC V7 processor and associated support circuitry for embedded space applications. The integer and floating-point units (90C601E & 90C602E) are based on the Cypress 7C601 and 7C602, with additional error-detection and recovery functions. The memory controller (MEC) implements system support functions such as address decoding, memory interface, DMA interface, UARTs, timers, interrupt control, write-protection, memory reconfiguration and error-detection. The core is designed to work at 25MHz, but using space qualified memories limits the system frequency to around 15 MHz, resulting in a performance of 10 MIPS and 2 MFLOPS.

Information on the ERC32 and a number of development support tools, such as the SPARC Instruction Simulator (SIS), are freely available on the Internet.  The following documents and SIS are available via anonymous ftp or pointing your web browser at ftp://ftp.estec.esa.nl/pub/ws/wsd/erc32.

  * ERC32 System Design Document

  * MEC Device Specification

Additionally, the SPARC RISC User's Guide from Matra MHS documents the functionality of the integer and floating point units including the instruction set information.  To obtain this document as well as ERC32 components and VHDL models contact:

     Matra MHS SA
     3 Avenue du Centre, BP 309,
     78054 St-Quentin-en-Yvelines,
     Cedex, France
     VOICE: +31-1-30607087
     FAX: +31-1-30640693

Amar Guennon (amar.guennon@matramhs.fr) is familiar with the ERC32.