USB OHCI

Endpoint Descriptor(ED)
Transfer Descriptor(TD)

• 8192 bytes with maximum of one physical page crossing

Host Controller Communications Area (HCCA)

• HccaInterruptTable
  
  • 32-entry
  • low order 5 bits of the current frame number is used as an index into the table
  • last of each interrupt list point to the isochronous list
    
• HccaFrameNumber
• HccaDoneHead

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OpenHCI -- Open Host Controller Interface Specification for USB
By Compaq, Microsoft, National Semiconductor, 09/14/99 2:33 PM, Release: 1.0a
http://www.compaq.com/productinfo/development/openhci.html
ftp://ftp.compaq.com/pub/supportinformation/papers/hcir1_0a.pdf