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68HC11 clocks

Discussion in 'Embedded' started by Jeff Fox, Apr 5, 2004.

  1. Jeff Fox

    Jeff Fox Guest

    In some literature about the 68HC11 I see a reference to an 8Mhz
    crystal and a 2MHz eClock. Instructions execute in a given number
    of clock cycles, but which clock?

    Best Wishes,
    Jeff Fox
    Jeff Fox, Apr 5, 2004
    #1
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  2. Jeff Fox

    James Beck Guest

    In article <>,
    says...
    > In some literature about the 68HC11 I see a reference to an 8Mhz
    > crystal and a 2MHz eClock. Instructions execute in a given number
    > of clock cycles, but which clock?
    >
    > Best Wishes,
    > Jeff Fox
    >

    Either, it just takes 4 more OSC clock ticks more than E clock ticks ;)

    But seriously.....
    Most of the documentation refers to E clock cycles.
    James Beck, Apr 5, 2004
    #2
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  3. Jeff Fox

    YB Guest

    Hi,
    The external frequency clock (8MHz for example) is four times the internal
    clock (2MHz). So, your instructions are executed with internal clock, 2MHz
    (500ns / cycle).

    Regards,

    Yvan
    http://www.ybdesign.fr




    "Jeff Fox" <> a écrit dans le message de news:
    ...
    > In some literature about the 68HC11 I see a reference to an 8Mhz
    > crystal and a 2MHz eClock. Instructions execute in a given number
    > of clock cycles, but which clock?
    >
    > Best Wishes,
    > Jeff Fox
    YB, Apr 6, 2004
    #3
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