STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

Secure digital input/output interface (SDIO)
RM0008
20 Secure digital input/output 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.
Connectivity line devices are STM32F105xx and STM32F107xx microcontrollers.
This section applies to high-density performance line devices only.
20.1 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.
456/995 Doc ID 13902 Rev 9