Altera cyclone V Technical Reference page 1014

14-68
Recovery after I/O Read Transmission Delay (N
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
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:
• register setting:
cmd
•
cmdarg
• Bit [31] set to 0
• Bits [7:2] set to 128
• All other bits set to 0
• Task file settings:
• Command field of the ATA task file set to 0xEC
• Reserved fields of the task file set to 0
•
bytcnt
The host controller uses the following settings for data retrieval (RW_BLK command):
Altera Corporation
on page 14-67
†
data_expected
†
register settings:
†
†
†
†
register and
block_size
) Timeout
ACIO
on page 14-56
) Timeout
ACIO
) timeout occurs for the CE-ATA card device, perform one of the
ACIO
†
†
†
†
†
bit set to 0
†
†
field of the register: set to 16
blksiz
bit is set to 1 in the
ccs_expected
†
†
†
†
†
†
SD/MMC Controller
Send Feedback
cv_5v4
2016.10.28
cmd