Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.6.5.8.2. Transmission Flow Details

The transmission flow details are provided as follows:

  1. Software configures the controller and issues start transfer.
  2. Software programs the controller to initialize the endpoint and other registers. Then it programs the event buffer pointers and issues a start transfer command.
  3. Read buffer pointer from cache.
  4. The host requests data in device mode or issues an out request in host mode. The MAC validates the request and then the data is moved to the TxFIFO.
    • A system bus validation is performed. If passed, an ACK packet is forwarded to the U3MAC. If there are errors in an ACK packet header, it is dropped, and a link level response is sent
  5. On receiving an ACK, the transfer count in cache is updated.
  6. When the ACK of the last packet is received, a new interrupt is raised.
  7. Software reads the event buffer to indicate that the transfer has completed.