ST STM32L4+ Series Reference Manual page 1962

Secure digital input/output MultiMediaCard interface (SDMMC)
54 Secure digital input/output MultiMediaCard interface
(SDMMC)
54.1 SDMMC main features
The SD/SDIO, embedded MultiMediaCard (e•MMC) host interface (SDMMC) provides an
interface between the AHB bus and SD memory cards, SDIO cards and e•MMC 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.
The SDMMC features include the following:
•
Compliance with Embedded MultiMediaCard System Specification Version 4.51.
Card support for three different databus modes: 1-bit (default), 4-bit and 8-bit.
•
Full compatibility with previous versions of MultiMediaCards (backward compatibility).
• Full compliance with SD memory card specifications version 4.1.
(SPI mode and UHS-II mode not supported).
•
Full compliance with SDIO card specification version 4.0.
Card support for two different databus modes: 1-bit (default) and 4-bit.
(SPI mode and UHS-II mode not supported).
•
Data transfer up to 104 Mbyte/s for the 8-bit mode.
(depending maximum allowed I/O speed).
•
Data and command output enable signals to control external bidirectional drivers.
The MultiMediaCard/SD bus connects cards to the host.
The current version of the SDMMC supports only one SD/SDIO/e•MMC card at any one
time and a stack of e•MMC.
54.2 SDMMC implementation
Variable delay (SDR104, HS200)
SDMMC_CKIN
SDMMC_CDIR, SDMMC_D0DIR
SDMMC_D123DIR
1. X = supported.
Variable delay (SDR104, HS200)
SDMMC_CKIN
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Table 381. STM32L4Rxxx and STM32L4Sxxx SDMMC features
SDMMC modes/features
Table 382. STM32L4P5xx and STM32L4Q5xx SDMMC features
SDMMC modes/features
RM0432 Rev 6
(1)
(1)
RM0432
SDMMC1
-
X
X
X
SDMMC1 SDMMC2
- -
X X