• Yokemate of Keyboards
    Yokemate of Keyboards
    Andreas_Wolf
    Posts: 12026 from 2003/5/22
    From: Germany
    > Another thing that puzzles me regarding Marvell and ARM:
    >
    > According to Marvell, their Sheeva core was developed from both the Intel XScale and
    > their own Feroceon CPU, both being ARMv5 ISA implementations. So one would assume
    > the Sheeva to be ARMv5 ISA compliant as well. But then there is this:
    >
    > "Compliant with the Cortex A8, Sheeva also supports both the ARMv6 and ARMv7
    > instruction sets, making it the world's first dual ARM ISA compatible CPU."
    > http://www.marvell.com/technologies/cpu_history/cpu_history.jsp
    >
    > What's Sheeva then? ARMv5 (like XScale and Feroceon), ARMv6 or ARMv7 (like
    > Cortex-A8)? Or a combination of these? Very confusing. Can anyone shed some light,
    > please?
    >
    >
    > Edit:
    >
    > http://www.marvell.com/files/technologies/SheevaUntoldStory.pdf from August 2008
    > provides some further clues:
    >
    > "2009 - A new flagship CPU: Newest CPU core features multi-Ghz performance, [...]
    > out-of-order execution, and full ARMv6 and ARMv7 compatibility"
    > (page 2, "Figure 1. Timeline of Marvell CPU development")
    >
    > "Marvell has extended its license to cover ARM v6 and v7, the most recent version of the
    > architecture. The company expects to sample its first ARM v7 CPU in late 2008."
    > (page 3)
    >
    > So it seems that contrary to the statement on the Marvell "History of CPU" webpage current
    > Sheeva core(s) are ARMv5 ISA compliant and *not* ARMv6 or ARMv7 ISA compliant but
    > *future* Sheeva cores are supposed to be.

    To answer my own question from 9 months ago in conclusion:

    There's currently 2 types of Sheeva cores: The older Sheeva PJ1, which implements ARMv5 ISA, and the new Sheeva PJ4, which implements ARMv7 ISA.

    http://www.marvell.com/company/news/press_detail.html?releaseID=1341
    http://www.google.com/search?q=marvell+sheeva+pj1+pj4

    Mystery solved, case closed :-)


    Edit:
    Changed press release URL due to Marvell website redesign.

    [ Edited by Andreas_Wolf on 2010/2/18 14:44 ]
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