Transfer Stop And Abort Commands - Altera Cyclone V Device Handbook

11-44

Transfer Stop and Abort Commands

For more information about packed commands, refer to JEDEC Standard No. 84-A441, available on the
JEDEC website.
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:
1. Set the wait_prvdata_complete bit of the cmd register to 0.
2. Set the stop_abort_cmd in the cmd register to 1, which ensures that the CIU stops.
The STOP_TRANSMISSION command is a non-data transfer command. For more information, refer to
Non-Data Transfer Commands.
Related Information
Non-Data Transfer Commands
Refer to this section for information on the STOP_TRANSMISSION command.
ABORT
The ABORT command can only be used with SDIO cards. To abort the function that is transferring data,
program the ABORT function number in the ASx[2:0] bits at address 0x06 of the card common control
register (CCCR) in the card device, using the IO_RW_DIRECT (CMD52) command. The CCCR is located
at the base of the card space 0x00 – 0xFF.
The ABORT command is a non-data transfer command. For more information, refer to Non-Data Transfer
†
Commands.
Related Information
Non-Data Transfer Commands
Refer to this section for information on the ABORT command.
Sending the ABORT Command
Perform the following steps to send the ABORT command to the SDIO card device:
1. Set the cmdarg register to include the appropriate command argument parameters listed in cmdarg
Register Settings for SD/SDIO ABORT Command.
2. Send the IO_RW_DIRECT command by setting the following fields of the cmd register:
Altera Corporation
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on page 11-35
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SD/MMC Controller
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