Intel® Agilex™ Hard Processor System Technical Reference Manual

ID 683567
Date 11/11/2022
Public

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16.5.5.6. Stream Read and Write

In a stream transfer, if the byte count is equal to 0, the software must also send the SD/SDIO STOP command. If the byte count is not 0, when a given number of bytes completes a transfer, the controller sends the STOP command automatically. Completion of this AUTO_STOP command is reflected by the Auto_command_done interrupt. A response to an AUTO_STOP command is written to the resp1 register. A stream transfer is allowed only for card interfaces with a 1‑bit data bus.

A stream read requires the same steps as the block read described in Single‑Block or Multiple‑Block Read, except for the following bits in the cmd register:

  • transfer_mode = 0x1 (for stream transfer)
  • cmd_index = 20 (SD/SDIO CMD20)

A stream write requires the same steps as the block write mentioned in Single‑Block or Multiple‑Block Write, except for the following bits in the cmd register:

  • transfer_mode = 0x1 (for stream transfer)
  • cmd_index = 11 (SD/SDIO CMD11)