Multimedia Card Registers
Table 18-29. SD_CMD Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
0x35 = CMD53 or ACMD5
0x36 = CMD54 or ACMD5
0x37 = CMD55 or ACMD5
0x38 = CMD56 or ACMD5
0x39 = CMD57 or ACMD5
0x3a = CMD58 or ACMD5
0x3b = CMD59 or ACMD5
0x3c = CMD60 or ACMD60
0x3d = CMD61 or ACMD61
0x3e = CMD62 or ACMD62
0x3f = CMD63 or ACMD63
23-22
CMD_TYPE
R/W
0h
Command type.
This register specifies three types of special commands: Suspend,
Resume and Abort.
These bits shall be cleared to 0b00 for all other commands.
0x0 = Others commands
0x1 = Upon CMD52 "Bus Suspend" operation
0x2 = Upon CMD52 "Function Select" operation
0x3 = Upon CMD12 or CMD52 "I/O Abort" command
21
DP
R/W
0h
Data present select.
This register indicates that data is present and mmc_dat line shall be
used.
It must be cleared to 0 in the following conditions: Command using
only mmc_cmd line.
Command with no data transfer but using busy signal on mmc_dat0.
Resume command.
0x0 = Command with no data transfer
0x1 = Command with data transfer
20
CICE
R/W
0h
Command Index check enable.
This bit must be set to 1 to enable index check on command
response to compare the index field in the response against the
index of the command.
If the index is not the same in the response as in the command, it is
reported as a command index error (SD_STAT[19] CIE bit set to1)
NoteThe CICE bit cannot be configured for an Auto CMD12, then
index check is automatically checked when this command is issued.
0x0 = Index check disable
0x1 = Index check enable
19
CCCE
R/W
0h
Command CRC check enable.
This bit must be set to 1 to enable CRC7 check on command
response to protect the response against transmission errors on the
bus.
If an error is detected, it is reported as a command CRC error
(SD_STAT[17] CCRC bit set to 1).
NoteThe CCCE bit cannot be configured for an Auto CMD12, and
then CRC check is automatically checked when this command is
issued.
0x0 = CRC7 check disable
0x1 = CRC7 check enable
18
Reserved
R
0h
17-16
RSP_TYPE
R/W
0h
Response type.
This bits defines the response type of the command.
0x0 = No response
0x1 = Response Length 136 bits
0x2 = Response Length 48 bits
0x3 = Response Length 48 bits with busy after response
15-6
Reserved
R
0h
3409
SPRUH73H – October 2011 – Revised April 2013
Multimedia Card (MMC)
Copyright © 2011–2013, Texas Instruments Incorporated