{big,little}-endian,wrong words? - TCP-IP

This is a discussion on {big,little}-endian,wrong words? - TCP-IP ; may i am too stupid to understand the words of big-endian and little- endian? my understand is that big-endian means "int" data type in memory layout from high bits to low bits ,and little-endian means "int" data type in memory ...

+ Reply to Thread
Results 1 to 8 of 8

Thread: {big,little}-endian,wrong words?

  1. {big,little}-endian,wrong words?

    may i am too stupid to understand the words of big-endian and little-
    endian?

    my understand is that big-endian means "int" data type in memory
    layout from high bits to low bits ,and little-endian means "int" data
    type in memory layout from low bits to high bits.

    so big-endian should be named big-start ,little-endian should be name
    little-start.

    if so ,it is easy to understand thes terminologys literally.

    any one agree me ?

  2. Re: {big,little}-endian,wrong words?

    zhangyefei.yefei@gmail.com schrieb:

    > any one agree me ?


    I disagree.

    Endianness is about the *byte* order, not the *bit* order. The bit order
    is usually not determinable by conventional means (i.e. without a logic
    analyzer).

    See http://en.wikipedia.org/wiki/Endianness

    Regards,
    Johannes

  3. Re: {big,little}-endian,wrong words?

    On Sep 11, 3:52*am, Johannes Bauer wrote:
    > zhangyefei.ye...@gmail.com schrieb:
    >
    > > any one agree me ?

    >
    > I disagree.
    >
    > Endianness is about the *byte* order, not the *bit* order. The bit order
    > is usually not determinable by conventional means (i.e. without a logic
    > analyzer).
    >
    > Seehttp://en.wikipedia.org/wiki/Endianness


    Actually, it refers to both bits and bytes.

    Some L1 schemes send the LSbit first, others send the LSbit last, in
    every byte transferred. For instance, the L1 of FDDI and ATM send the
    LSbit last, MSbit first, byte by byte. But Ethernets send LSbit first.
    That is also referred to as endianness.

    At the byte level, RFC 791 Appendix B says that IP is big endian.

    And although this always causes great controversy, the headers of
    Ethernet, FDDI, and ATM frames are pretty clearly meant to be big
    endian byte order also, if you look at any field of the header where
    byte order matters. Such as, the "length" field, for example.

    Bert

  4. Re: {big,little}-endian,wrong words?

    On Sep 11, 1:02*am, "zhangyefei.ye...@gmail.com"
    wrote:
    > may i am *too stupid *to understand the words of big-endian and little-
    > endian?
    >
    > my understand is that big-endian means *"int" data type in memory
    > layout from high bits to low bits ,and little-endian means *"int" data
    > type in memory *layout from low bits to high *bits.
    >
    > so big-endian should be named big-start ,little-endian should be name
    > little-start.
    >
    > if so ,it is easy to understand *thes terminologys literally.



    Basically you're correct, although people often discuss endianness in
    terms of units larger than bits (typically bytes), particularly in
    programs (at the hardware level, for example, within the stream of
    bits on an Ethernet cable, we almost always discuss it at the bit
    level).

    Your confusion is most likely do to the terms themselves, which
    actually come from Jonathan Swift's, "Gulliverís Travels" where there
    were two rival kingdoms, one where they ate eggs starting at the
    little end (aka the "little endians") and the other in which it was
    correct to eat the egg from the big end. So it's really a statement
    of which end you start the number (or egg) from.


  5. Re: {big,little}-endian,wrong words?

    On Sep 12, 8:16*am, "robertwess...@yahoo.com"
    wrote:
    > On Sep 11, 1:02*am, "zhangyefei.ye...@gmail.com"
    >
    > wrote:
    > > may i am *too stupid *to understand the words of big-endian and little-
    > > endian?

    >
    > > my understand is that big-endian means *"int" data type in memory
    > > layout from high bits to low bits ,and little-endian means *"int" data
    > > type in memory *layout from low bits to high *bits.

    >
    > > so big-endian should be named big-start ,little-endian should be name
    > > little-start.

    >
    > > if so ,it is easy to understand *thes terminologys literally.

    >
    > Basically you're correct, although people often discuss endianness in
    > terms of units larger than bits (typically bytes), particularly in
    > programs (at the hardware level, for example, within the stream of
    > bits on an Ethernet cable, we almost always discuss it at the bit
    > level).
    >
    > Your confusion is most likely do to the terms themselves, which
    > actually come from Jonathan Swift's, "Gulliverís Travels" where there
    > were two rival kingdoms, one where they ate eggs starting at the
    > little end (aka the "little endians") and the other in which it was
    > correct to eat the egg from the big end. *So it's really a statement
    > of which end you start the number (or egg) from.


    Oh ,i see now.
    My confusion comes from my poor english ,and your saying " they ate
    eggs starting at the little end " make me understand the actual
    meaning of big-endian and little-endian.
    Thank you.
    Thanks all.

  6. Re: {big,little}-endian,wrong words?

    On 2008-09-11 20:16:42 -0400, "robertwessel2@yahoo.com"
    said:

    > Your confusion is most likely do to the terms themselves, which
    > actually come from Jonathan Swift's, "Gulliver’s Travels" where there
    > were two rival kingdoms, one where they ate eggs starting at the
    > little end (aka the "little endians") and the other in which it was
    > correct to eat the egg from the big end. So it's really a statement
    > of which end you start the number (or egg) from.


    Side note? That is a damn cool piece of trivia I did not know until
    today - thanks!

    /dmfh

    --
    _ __ _
    __| |_ __ / _| |_ 01100100 01101101
    / _` | ' \| _| ' \ 01100110 01101000
    \__,_|_|_|_|_| |_||_| dmfh(-2)dmfh.cx


  7. Re: {big,little}-endian,wrong words?

    Johannes Bauer wrote:

    > Endianness is about the *byte* order, not the *bit* order. The bit order
    > is usually not determinable by conventional means (i.e. without a logic
    > analyzer).


    It can be either, or both. Sometimes bit and byte order are different.

    There are few bit addressable processors now, though some have
    instructions that do bitwise operations. Otherwise, bits tend
    to be numbered in processor documentation, and not always
    consistent with the byte order.

    Also, note the byte order in VAX floating point formats.
    (Fixed point is little-endian.) The byte addressable VAX
    stores floating point in little endian 16 bit words, which
    are in big endian order.

    For ethernet, the bit order on the wire is normally not visible.
    It is only the length field if IEEE 802.3 frames that byte order
    is significant to ethernet. (Not counting higher layer protocols.)

    Ethernet MAC addresses are bit patterns, and don't have most and
    least significant bits. (Though in some cases one may consider
    that they do.)

    -- glen


  8. Re: {big,little}-endian,wrong words?


    wrote in message
    news:07bb1588-106c-41b7-a8bc-d346278de9d9@i24g2000prf.googlegroups.com...
    > may i am too stupid to understand the words of big-endian and little-
    > endian?
    >
    > my understand is that big-endian means "int" data type in memory
    > layout from high bits to low bits ,and little-endian means "int" data
    > type in memory layout from low bits to high bits.
    >
    > so big-endian should be named big-start ,little-endian should be name
    > little-start.
    >
    > if so ,it is easy to understand thes terminologys literally.
    >
    > any one agree me ?


    Lack of agreement on endianness has hindered the industry greatly. Little
    endian is the way to go and the internet should be switched over to little
    endian before we turn the clocks away from daylight savings time.

    Tony



+ Reply to Thread