Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 8/15/2024
Public
Document Table of Contents

16.5.5.7. Packed Commands

To reduce overhead, read and write commands can be packed in groups of commands—either all read or all write—that transfer the data for all commands in the group in one transfer on the bus. Use the SD/SDIO SET_BLOCK_COUNT (CMD23) command to state ahead of time how many blocks are ready to be transferred. Then issue a single READ_MULTIPLE_BLOCK or WRITE_MULTIPLE_BLOCK command to read or write multiple blocks.
  • SET_BLOCK_COUNT—set block count (number of blocks transferred using the READ_MULTIPLE_BLOCK or WRITE_MULTIPLE_BLOCK command)
  • READ_MULTIPLE_BLOCK—multiple-block read command
  • WRITE_MULTIPLE_BLOCK—multiple-block write command

Packed commands are organized in packets by the application software and are transparent to the controller.