Altera Cyclone V Device Handbook page 733

cv_54011
2013.12.30
Recovery after CCS Timeout
If a timeout occurs while waiting for the CCS, the host needs to send the CCSD command followed by a
STOP command to abort the pending ATA command. The host can set up the controller to send an
internally-generated STOP command after sending the CCSD pattern:
• Send CCSD command set the send_ccsd bit in the ctrl register to 1.
• Send external STOP command terminate the data transfer between the CE-ATA card device and the
controller. For more information about sending the STOP command, refer to Transfer Stop and Abort
Commands.
• Send internal STOP command set the send_auto_stop_ccsd bit in the ctrl register to 1, which
tells the controller to send the internally-generated STOP command. After sending the STOP command,
the controller sets the acd bit in the rintsts register to 1. The send_auto_stop_ccsd bit must
be set to 1 along with setting the send_ccsd bit.
Related Information
Transfer Stop and Abort Commands
Refer to this section for more information about sending the STOP command.
Recovery after I/O Read Transmission Delay (N
If the I/O read transmission delay (N
following steps to recover from the timeout:
• If the CCS is expected from the CE-ATA card device (that is, the ccs_expected bit is set to 1 in the
cmd register), follow the steps in Recovery after CCS Timeout.
• If the CCS is not expected from the CE-ATA card device, perform the following steps:
1. Send an external STOP command.
2. Terminate the data transfer between the controller and CE-ATA card device.
Related Information
Recovery after CCS Timeout
For more information about what steps to take if the CCS is expected from the CE-ATA card device.
Reduced ATA Command Set
It is necessary for the CE-ATA card device to support the reduced ATA command subset. This section
describes the reduced command set.
The IDENTIFY DEVICE Command
The IDENTIFY DEVICE command returns a 512-byte data structure to the host that describes device-specific
information and capabilities. The host issues the IDENTIFY DEVICE command only if the MMC block size
is set to 512 bytes. Any other MMC block size has indeterminate results.
The host issues a RW_REG command for the ATA command, and the data is retrieved with the RW_BLK
command.
The host controller uses the following settings while sending a RW_REG command for the IDENTIFY
DEVICE ATA command. The following list shows the primary bit settings:
SD/MMC Controller
Send Feedback
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) Timeout
ACIO
) timeout occurs for the CE-ATA card device, perform one of the
ACIO
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Recovery after CCS Timeout
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11-55
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