Sdio Interface (Sdio); Sdio Main Features - ST STM32F102 Series Reference Manual

SDIO interface (SDIO)

19 SDIO interface (SDIO)
Low-density devices are STM32F101xx, STM32F102xx and STM32F103xx
microcontrollers where the Flash memory density ranges between 16 and 32 Kbytes.
Medium-density devices are STM32F101xx, STM32F102xx and STM32F103xx
microcontrollers where the Flash memory density ranges between 64 and 128 Kbytes.
High-density devices are STM32F101xx and STM32F103xx microcontrollers where the
Flash memory density ranges between 256 and 512 Kbytes.
This section applies to high-density performance line devices only.
19.1

SDIO main features

The SD/SDIO MMC card host interface (SDIO) provides an interface between the AHB
peripheral bus and MultiMediaCards (MMCs), SD memory cards, SDIO cards and CE-ATA
devices.
The MultiMediaCard system specifications are available through the MultiMediaCard
Association website at www.mmca.org, published by the MMCA technical committee.
SD memory card and SD I/O card system specifications are available through the SD card
Association website at www.sdcard.org.
CE-ATA system specifications are available through the CE-ATA workgroup website at
www.ce-ata.org.
The SDIO features include the following:
●
Full compliance with MultiMediaCard System Specification Version 4.2. Card support
for three different databus modes: 1-bit (default), 4-bit and 8-bit
●
Full compatibility with previous versions of MultiMediaCards (forward compatibility)
●
Full compliance with SD Memory Card Specifications Version 2.0
●
Full compliance with SD I/O Card Specification Version 2.0: card support for two
different databus modes: 1-bit (default) and 4-bit
●
Full support of the CE-ATA features (full compliance with CE-ATA digital protocol
Rev1.1)
●
Data transfer up to 48 MHz for the 8 bit mode
● Data and command output enable signals to control external bidirectional drivers.
Note: 1 The SDIO does not have an SPI-compatible communication mode.
2 The SD memory card protocol is a superset of the MultiMediaCard protocol as defined in the
MultiMediaCard system specification V2.11. Several commands required for SD memory
devices are not supported by either SD I/O-only cards or the I/O portion of combo cards.
Some of these commands have no use in SD I/O devices, such as erase commands, and
thus are not supported in the SDIO. In addition, several commands are different between SD
memory cards and SD I/O cards and thus are not supported in the SDIO. For details refer to
SD I/O card Specification Version 1.0. CE-ATA is supported over the MMC electrical
interface using a protocol that utilizes the existing MMC access primitives. The interface
electrical and signaling definition is as defined in the MMC reference.
The MultiMediaCard/SD bus connects cards to the controller.
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