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/
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Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
SDIO Interface
(
SDIO
)
Main features of SDIO
SDIO interface defines SD card, SD I/O card, Multimedia Card (MMC) host interface. It provides data transfer
between AHB peripheral bus and SD memory card, SDIO card, Multimedia Card (MMC) and CE-ATA devices.
Among them, the supported multimedia card system specifications are published by the MMCA technical committee
and can be obtained on the website of the Multimedia Card Association (www.mmca.org), and the supported CE-
ATA system specifications can be found in the CE-ATA working group. Available on the website (www.ce-ata.org),
supported SD memory cards and SD I/O card system specifications are available through the SD Card Association
website (www.sdcard.org).
Main features of SDIO are as follows:
SD card: fully compatible with SD memory card specification version 2.0.
SD I/O: Fully compatible with SD I/O card specification version 2.0, there are two different data bus modes: 1-
bit (default) and 4-bit.
MMC: Fully compatible with Multimedia Card System Specification Version 4.2 and earlier versions. There are
three different data bus modes: 1-bit (default), 4-bit and 8-bit.
CE-ATA: fully compatible with CE-ATA digital protocol version 1.1, fully supports CE-ATA function.
Up to 48MHz data transfer rate in 8-bit data bus mode.
Support interrupt and DMA request.
Supports data and command output enable signals for controlling external bidirectional drivers.
Notice:
1. SDIO has no SPI compatible communication mode.
2. In version 2.11 of the Multimedia Card System Specification, it is defined that the SD memory card protocol only
supports the I/O part of the SD card or composite card in I/O mode, and does not support many required commands
in the SD storage device, such as erasing etc. some commands don't work in SDI/O devices, so SDIO doesn't support
these commands either. In addition, some commands are different in SD memory card and SD I/O card, and SDIO
does not support these commands.
SDIO supports only one SD/SDIO/MMC 4.2 card or CE-ATA device at a time, but can support multiple MMC version
4.1 or earlier cards.