SDI Technologies SDIO Card manual Differences with SD Memory Specification, Sdio Command List

©Copyright 2000-2007 SD Card Association

SDIO Simplified Specification Version 2.00

4.Differences with SD Memory Specification

4.1SDIO Command List

Table A-14 shows the list of commands accepted by SD memory and SDIO cards when using the SD bus interface. Table A-15 shows the list of commands accepted by SD memory and SDIO cards when using the SPI bus interface.

4.2Unsupported SD Memory Commands

Several commands required for SD Memory cards are not supported by either SDIO-only cards or the I/O portion of Combo cards. Some of these commands have no use in SDIO cards such as Erase commands and thus are not supported in SDIO. In addition, there are several commands for SD memory cards that have different commands when used with the SDIO section of a card. Table 4-1 lists these SD Memory commands and the equivalent SDIO commands. For a complete list of supported and unsupported commands, see Table A-14 and Table A-15.

SD Memory	SDIO	Comment
Command	Command
CMD0	CMD52 (write to	The reset command (CMD0) is only used for memory or the
	I/O reset in	memory portion of Combo cards. In order to reset an I/O only
	CCCR)	card or the I/O portion of a combo card, use CMD52 to write a
		1 to the RES bit in the CCCR (bit 3 of register 6). Note that in
		the SD mode, CMD0 is only used to indicate entry into SPI
		mode and shall be supported. An I/O only card or the I/O
		portion of a combo card is not reset with CMD0
CMD12	CMD52 (write to	In order to abort the block transfer of data, SD memory use
	I/O abort)	CMD12. In order to abort an I/O transaction, use CMD52 to
		write to the abort register in the CCCR (bits 2:0 of register 6)
		See 4.8 for details.
CMD16	CMD52 (write to	CMD16 sets the block length for SD memory. In order to set
	I/O Block	the block length for each I/O function, use CMD52 to write the
	Length)	block length in the FBR
CMD2	NONE	The CID register does not exist in an SDIO only card
CMD4	NONE	The DSR register does not exist in an SDIO only card
CMD9	NONE	The CSD register does not exist in an SDIO only card
CMD10	NONE	The CID register does not exist in an SDIO only card
CMD13	NONE	An SDIO only card or the I/O portion of a combo card does not
		support the same SEND_STATUS (CMD13) protocol the SD
		memory uses. See 4.10.8.
ACMD6	CMD52 (write to	SET_BUS_WIDTH is handled by a write to the CCCR. See
	Bus_Width [1:0]	4.4 for details.
	in CCCR)
ACMD13	NONE	The SD Status register does not exist in an SDIO only card
ACMD41	CMD5	SDIO cards and hosts use the IO_SEND_OP_COND
		Command (CMD5). See 3.2
ACMD42	CMD52	In the SD mode, the pull-up resistor on DAT[3] is controlled by
		writing to the CD Disable bit in the CCCR. For Combo Cards,
		this resistor is enabled unless both the memory and the I/O
		control registers are set to disable the resistor. For details, see
		section 4.6
ACMD51	NONE	The SCR register does not exist in an SDIO only card
CMD17,	CMD53	I/O block operations use CMD53, rather than memory block

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