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High bandwidth USB 2.0 Endpoints

Jimmy_JamesJimmy_James Member - All Emails Posts: 109
All,

While doing some research on the web I've seen some info stating that, for
Windows XP, high bandwidth transfers are only supported for iso endpoints.

Are there any versions of the Windows OS + service pack that extends high
bandwidth transfers to interrupt in/out endpoints?
Does any one know of a 3rd party controller/driver that supports high
bandwidth transfers for interrupt in/out endpoints?

Thanks in advance.

Comments

  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    Hi Al,
    Hi Jimmy,

    my experince is that high bandwidth transfers (HBW) are not supported,
    but maybee I'm missing something. I tried to implement it some time ago,
    but without any success.
    At that time Windows 7 was not available yet, so I can not tell you that
    OS version.

    I'm still interested in any news about the HBW mode, so please let us know.

    /Uwe


    Jimmy James schrieb:
    > All,
    >
    > While doing some research on the web I've seen some info stating that, for
    > Windows XP, high bandwidth transfers are only supported for iso endpoints.
    >
    > Are there any versions of the Windows OS + service pack that extends high
    > bandwidth transfers to interrupt in/out endpoints?
    > Does any one know of a 3rd party controller/driver that supports high
    > bandwidth transfers for interrupt in/out endpoints?
    >
    > Thanks in advance.
    >
    >


    Email secured by Check Point at OSR.COM
  • Tim_RobertsTim_Roberts Member - All Emails Posts: 13,489
    On Fri, Jul 24, 2009 at 10:21:14AM +0200, uwekirst wrote:
    >
    > my experince is that high bandwidth transfers (HBW) are not supported,
    > but maybee I'm missing something. I tried to implement it some time ago,
    > but without any success.

    We should be clear that we are talking only about interrupt endpoints
    here. High-bandwidth isochronous endpoints work just fine, and have
    done so all along.

    I've never tried a high-bandwidth interrupt endpoint, so I don't have
    direct experience, although this is the first time I've ever seen an
    implication that they aren't supported.
    --
    Tim Roberts, [email protected]
    Providenza & Boeklheide, Inc.

    Email secured by Check Point at OSR.COM

    Tim Roberts, [email protected]
    Providenza & Boekelheide, Inc.

  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    Hi Tim,

    here is someone else reporting that HBW interrupt transfers are not working:

    http://www.tech-archive.net/Archive/Development/microsoft.public.development.device.drivers/2004-10/1488.html

    thanks,
    /Uwe

    [email protected] schrieb:
    > I've never tried a high-bandwidth interrupt endpoint, so I don't have
    > direct experience, although this is the first time I've ever seen an
    > implication that they aren't supported.
    >


    Email secured by Check Point at OSR.COM
  • Jimmy_JamesJimmy_James Member - All Emails Posts: 109
    I've actually seen this. Jan Axelson's book also says that high bandwidth
    transfers are not supported for interrupt endpoints on WinXP. What makes me
    skeptical though is that this information is all several years old and I
    wonder if this issue has been addressed in a service pack or new version of
    the OS. Can anyone confirm or deny?


    "uwekirst" wrote in message news:[email protected]
    > Hi Tim,
    >
    > here is someone else reporting that HBW interrupt transfers are not
    > working:
    >
    > http://www.tech-archive.net/Archive/Development/microsoft.public.development.device.drivers/2004-10/1488.html
    >
    > thanks,
    > /Uwe
    >
    > [email protected] schrieb:
    >> I've never tried a high-bandwidth interrupt endpoint, so I don't have
    >> direct experience, although this is the first time I've ever seen an
    >> implication that they aren't supported.
    >>
    >
    >
    > Email secured by Check Point at OSR.COM
    >
  • Glen_Slick-1Glen_Slick-1 Member Posts: 104
    In the Windows 7 version of USBEHCI.SYS I cannot find any code which ever sets the EHCI Queue Head Endpoint Capabilities DWORD2 bits 31:30 High-Bandwidth Pipe Multiplier field for a high-speed Interrupt endpoint to a value other than 1. (See Table 3-20 in the EHCI specification).

    Based on that it would appear that high bandwidth (i.e. more than one transaction per endpoint per micro-frame) Interrupt endpoints are not supported in Windows 7, nor in any previous versions.

    -Glen
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