Altera cyclone V Technical Reference page 1015

cv_5v4
2016.10.28
• register settings:
cmd
•
ccs_expected
•
data_expected
•
cmdarg
• Bit [31] set to 0 (read operation)
• Bits [15:0] set to 1 (data unit count = 1)
• All other bits set to 0
•
bytcnt
The READ DMA EXT Command
The READ DMA EXT command reads a number of logical blocks of data from the card device using the
Data-In data transfer protocol. The host uses a RW_REG command to issue the ATA command and the
RW_BLK command for the data transfer.
The WRITE DMA EXT Command
The WRITE DMA EXT command writes a number of logical blocks of data to the card device using the
Data-Out data transfer protocol. The host uses a RW_REG command to issue the ATA command and the
RW_BLK command for the data transfer.
The STANDBY IMMEDIATE Command
This ATA command causes the card device to immediately enter the most aggressive power management
mode that still retains internal device context. No data transfer (RW_BLK) is expected for this command.
For card devices that do not provide a power savings mode, the STANDBY IMMEDIATE command
returns a successful status indication. The host issues a RW_REG command for the ATA command, and
the status is retrieved with the SD/SDIO CMD39 or RW_REG command. Only the status field of the ATA
task file contains the success status; there is no error status.
The host controller uses the following settings while sending the RW_REG command for the STANDBY
IMMEDIATE ATA command:
• register setting:
cmd
•
cmdarg
• Bit [31] set to 1
• Bits [7:2] set to 4
• All other bits set to 0
• Task file settings:
• Command field of the ATA task file set to 0xE0
• Reserved fields of the task file set to 0
•
bytcnt
The FLUSH CACHE EXT Command
For card devices that buffer/​cache written data, the FLUSH CACHE EXT command ensures that buffered
data is written to the card media. For cards that do not buffer written data, the FLUSH CACHE EXT
command returns a success status. No data transfer (RW_BLK) is expected for this ATA command.
The host issues a RW_REG command for the ATA command, and the status is retrieved with the SD/SDIO
CMD39 or RW_REG command. There can be error status for this ATA command, in which case fields
other than the status field of the ATA task file are valid.
SD/MMC Controller
Send Feedback
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set to 1
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set to 1
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register settings:
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register and
block_size
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data_expected
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register settings:
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register and
block_size
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field of the register: set to 512
blksiz
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bit set to 0
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field of the register: set to 16
blksiz
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The READ DMA EXT Command
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Altera Corporation
14-69
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