eMMC Commands

Abbr. Type Argument Resp Description

Basic commands (class 0 and class 1)

CMD0

Abbr. Type Argument Resp Description
GO_IDLE_STATE bc [31:0] 00000000 None Resets the Device to idle state
GO_PRE_IDLE_STATE bc [31:0] F0F0F0F0 None Resets the Device to pre-idle state
BOOT_INITIATION - [31:0]FFFFFFFA None Initiate alternative boot operation

CMD1

Abbr. Type Argument Resp Description
SEND_OP_COND bcr [31:0] OCR without busy R3 Asks Device, in idle state, to send its Operating Conditions Register contents in the response on the CMD line.

CMD2

Abbr. Type Argument Resp Description
ALL_SEND_CID bcr [31:0] stuff bits R2 Asks Device to send its CID number on the CMD line

CMD3

Abbr. Type Argument Resp Description
SET_RELATIVE_ADDR ac [31:16] RCA, [15:0] stuff bits R1 Assigns relative address to the Device

CMD4

Abbr. Type Argument Resp Description
SET_DSR bc [31:16] DSR, [15:0] stuff bits - Programs the DSR of the Device

CMD5

Abbr. Type Argument Resp Description
SLEEP_AWAKE ac [31:16] RCA, [15]Sleep/Awake, [14:0] stuff bits R1b Toggles the Device between Sleep state and Standby state.

CMD6

Abbr. Type Argument Resp Description
SWITCH ac [31:26] Set to 0, [25:24] Access, [23:16] Index, [15:8] Value, [7:3] Set to 0, [2:0] Cmd Set R1b Switches the mode of operation of the selected Device or modifies the EXT_CSD registers.

CMD7

Abbr. Type Argument Resp Description
SELECT/DESELECT_CARD ac [31:16] RCA, [15:0] stuff bits R1/R1b Command toggles a device between the standby and transfer states or between the programming and disconnect states.

CMD8

Abbr. Type Argument Resp Description
SEND_EXT_CSD adtc [31:0] stuff bits R1 Device sends its EXT_CSD register as a block of data.

CMD9

Abbr. Type Argument Resp Description
SEND_CSD ac [31:16] RCA, [15:0] stuff bits R2 Addressed Device sends its Device-pecific data (CSD) on the CMD line.

CMD10

Abbr. Type Argument Resp Description
SEND_CID ac [31:16] RCA, [15:0] stuff bits R2 Addressed Device sends its Device identification (CID) on CMD the line.

CMD12

Abbr. Type Argument Resp Description
STOP_TRANSMISSION ac [31:16] RCA, [15:1] stuff bits, [0] HPI R1/R1b Forces the Device to stop transmission. If HPI flag is set the device shall interrupt its internal operations in a well-defined timing.

CMD13

Abbr. Type Argument Resp Description
SEND_STATUS ac [31:16] RCA, [15] SQS, [14:1] stuff bits, [0] HPI R1 In case SQS bit = 0: Addressed Device sends its status register. If HPI flag is set the device shall interrupt its internal operations in a well-defined timing. In case SQS bit = 1: indicate that this is a QSR query. In response device shall send the QSR (Queue Status Register). In this case HPI must be set to ‘0’

CMD14

Abbr. Type Argument Resp Description
BUSTEST_R adtc [31:0] stuff bits R1 A host reads the reversed bus testing data pattern from a Device.

CMD15

Abbr. Type Argument Resp Description
GO_INACTIVE_STATE ac [31:16] RCA, [15:0] stuff bits - Sets the Device to inactive state

CMD19

Abbr. Type Argument Resp Description
BUSTEST_W adtc [31:0] stuff bits R1 A host sends the bus test data pattern to a Device

NOTE 1 - CMD7, R1 while selecting from Stand-By State to Transfer State; R1b while selecting from Disconnected State to Programming State.
NOTE 2 - CMD12, RCA in CMD12 is used only if HPI bit is set. The argument does not imply any RCA check on the device side.
NOTE 3 - CMD12, R1 for read cases and R1b for write cases.

Block-oriented read commands (class 2)

CMD16

Abbr. Type Argument Resp Description
SET_BLOCKLEN ac [31:0] block length R1 Sets the block length (in bytes) for all following block commands (read and write). Default block length is specified in the CSD

CMD17

Abbr. Type Argument Resp Description
READ_SINGLE_BLOCK adtc [31:0] data address R1 Reads a block of the size selected by the SET_BLOCKLEN command

CMD18

Abbr. Type Argument Resp Description
READ_MULTIPLE_BLOCK adtc [31:0] data address R1 Continuously transfers data blocks from Device to host until interrupted by a stop command, or the requested number of data blocks is transmitted If sent as part of a packed read command, the argument shall contain the first read data address in the pack (address of first individual read command inside the pack).

CMD21

Abbr. Type Argument Resp Description
SEND_TUNING_BLOCK adtc [31:0] stuff bits R1 128 clocks of tuning pattern (64 byte in 4bit mode or 128 byte in 8 bit mode) is sent for HS200 optimal sampling point detection.

NOTE 1 - CMD17 & CMD18, Data address for media =<2 32="" gb="" is="" a="" bit="" byte="" address="" and="" data="" for="" media=""> 2GB is a 32 bit sector (512 B) address.
NOTE 2 - CMD17, The transferred data must not cross a physical block boundary, unless READ_BLK_MISALIGN is set in the CSD register.

Block-oriented write commands (class 4)

CMD23 (default)

Abbr. Type Argument Resp Description
SET_BLOCK_COUNT ac [31] Reliable Write Request, [30] ‘0’ non- packed, [29] tag request,[28:25] context ID, [24]: forced programming, [23:16] set to 0, [15:0] number of blocks R1 Defines the number of blocks (read/write) and the reliable writer parameter (write) for a block read or write command.

CMD23 (packed)

Abbr. Type Argument Resp Description
SET_BLOCK_COUNT ac [31] set to 0, [30] ‘1’ packed, [29:16] set to 0, [15:0] number of blocks R1 Defines the number of blocks (read/write) for the following packed write command or for the header of the following packed read command.

CMD24

Abbr. Type Argument Resp Description
WRITE_BLOCK adtc [31:0] data address R1 Writes a block of the size selected by the

SET_BLOCKLEN command. |

CMD25

Abbr. Type Argument Resp Description
WRITE_MULTIPLE_BLOCK adtc [31:0] data address R1 Continuously writes blocks of data until a STOP_TRANSMISSION follows or the requested number of block received. If sent as a packed command (either packed write, or the header of packed read) the argument shall contain

the first read/write data address in the pack (address of first individual command inside the pack). |

CMD26

Abbr. Type Argument Resp Description
PROGRAM_CID adtc [31:0] stuff bits R1 Programming of the Device identification register. This command shall be issued only once. The Device contains hardware to prevent this operation after the first programming. Normally this command is reserved for the manufacturer.

CMD27

Abbr. Type Argument Resp Description
PROGRAM_CSD adtc [31:0] stuff bits R1 Programming of the programmable bits of the CSD.

CMD49

Abbr. Type Argument Resp Description
SET_TIME adtc [31:0] stuff bits R1 Sets the real time clock according to the RTC information in the 512 B data block.

NOTE 1 - CMD24 & CMD25, Data address for media =<2 32="" gb="" is="" a="" bit="" byte="" address="" and="" data="" for="" media=""> 2GB is a 32 bit sector (512 B) address.
NOTE 2 - CMD24, The transferred data must not cross a physical block boundary, unless READ_BLK_MISALIGN is set in the CSD register.

Block-oriented write protection commands (class 6)

Erase commands (class 5)

I/O mode commands (class 9)

Lock Device commands (class 7)

Application-specific commands (class 8)

Security Protocols (class 10)

Command Queue (Class 11)

results matching ""

    No results matching ""