Transfer Stop And Abort Commands - Altera cyclone V Technical Reference

14-56
Packed Commands
Auto_command_done interrupt. A response to an AUTO_STOP command is written to the
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
•
transfer_mode
•
cmd_index
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
•
transfer_mode
•
cmd_index
Related Information
Single-Block or Multiple-Block Read
•
Refer to this section for more information about a stream read.
Single-Block or Multiple-Block Write
•
Refer to this section for more information about a stream write.
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 will 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.
Related Information
www.jedec.org
For more information about packed commands, refer to JEDEC Standard No. 84-A441, available on the
JEDEC website.

Transfer Stop and Abort Commands

This section describes stop and abort commands. The SD/SDIO STOP_TRANSMISSION command can
terminate a data transfer between a memory card and the controller. The ABORT command can terminate
an I/O data transfer for only an SDIO card.
STOP_TRANSMISSION (CMD12)
The host can send the STOP_TRANSMISSION (CMD12) command on the CMD pin at any time while a
data transfer is in progress. Perform the following steps to send the STOP_TRANSMISSION command to
the SD/SDIO card device:
Altera Corporation
= 0x1 (for stream transfer)
= 20 (SD/SDIO CMD20)
= 0x1 (for stream transfer)
= 11 (SD/SDIO CMD11)
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register:
cmd
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register:
cmd
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on page 14-50
on page 14-53
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SD/MMC Controller
cv_5v4
2016.10.28
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