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• Set the command index to 0x52 (IO_RW_DIRECT).
†
• Set the
stop_abort_cmd
bit of the
cmd
register to 1 to inform the controller that the host aborted
the data transfer.
†
• Set the
wait_prvdata_complete
bit of the
cmd
register to 0.
†
3. Wait for the
cmd
bit in the
rintsts
register to change to 1.
†
4. Read the response to the IO_RW_DIRECT command (R5) in the response registers for any errors.
†
For more information about response values, refer to the Physical Layer Simplified Specification, Version
3.01, available on the SD Association website.
Related Information
To learn more about how SD technology works, visit the SD Association website.
cmdarg Register Settings for SD/SDIO ABORT Command
†
Table 11-21: cmdarg Register Settings for SD/SDIO ABORT Command
Value
Contents
Bits
1
R/W flag
31
0, for access to the CCCR in the card device
Function number
30:28
1, if needed to read after write
RAW flag
27
-
Don't care
26
0x06
Register address
25:9
-
Don't care
8
Function number to abort
Write data
7:0
Internal DMA Controller Operations
For better performance, you can use the internal DMA controller to transfer data between the host and the
controller. This section describes the internal DMA controller’s initialization process, and transmission
sequence, and reception sequence.
Internal DMA Controller Initialization
To initialize the internal DMA controller, perform the following steps:
†
1. Set the required
bmod
register bits:
†
Altera Corporation
SD/MMC Controller
11-45
cmdarg Register Settings for SD/SDIO ABORT Command
†
cv_54011
2013.12.30