INFO: Windows CE Universal Serial Bus Transfers Size Limitations (250382)



The information in this article applies to:

  • Microsoft Windows CE Operating System, Versions 2.12
  • Microsoft Windows CE Operating System, Versions 2.11
  • Microsoft Windows CE Platform Builder 2.11
  • Microsoft Windows CE Platform Builder 2.12
  • Microsoft Windows CE Platform Builder 3.0 (BETA)
  • Microsoft Windows CE Operating System, Versions 3.0

This article was previously published under Q250382

SUMMARY


Microsoft Windows CE Platform Builder 2.10 and later has limits on the amounts of data per transfer. All data transfers that use the Universal Serial Bus Driver Interface (USBDI) transfer functions are limited to 8 kilobyte (K) of data per transfer. Isochronous transfers are limited to eight frames and 1K per frame globally. This is due to internal limitations in Microsoft's Universal Serial Bus (USB) implementation. If you port USB client drivers from Microsoft Windows NT, Windows 95 or Windows 98, make changes in your code to enforce a limit of 8K per transfer.


Modification Type:MinorLast Reviewed:12/27/2003
Keywords:kbinfo KB250382