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Diffstat (limited to 'user/bsps/arm/stm32h7.rst')
| -rw-r--r-- | user/bsps/arm/stm32h7.rst | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/user/bsps/arm/stm32h7.rst b/user/bsps/arm/stm32h7.rst index 8a41ffc..b508595 100644 --- a/user/bsps/arm/stm32h7.rst +++ b/user/bsps/arm/stm32h7.rst @@ -47,3 +47,29 @@ USB Host Driver --------------- The USB host driver ``dwc_otg`` is provided by the ``libbsd``. + +SD/MMC Driver +------------- + +The SDMMC driver ``st_sdmmc`` is provided by the ``libbsd``. + +The default initialization is done for the STM32H743I-EVAL 2 board. + +To use different pins, you can create a ``HAL_SD_MspInit()`` function in your +application that overwrites the default one defined in ``RTEMS``. If you don't +have direction lines like on the evaluation board, you can just skip +initializing these pins. + +If you want to use a different number of data lines, another polarity for the +data direction pins, a different voltage or similar, you have to redefine +``st_sdmmc_get_config()`` (normally provided by ``libbsd``) in your application. + +Known limitations: + +* Currently 1.8V signaling is not implemented. Therefore higher speeds like used + for UHS cards are not available. All cards fall back to High Speed transfers. +* The driver uses the IDMA only. MDMA is currently not implemented. For SDMMC1 + that means that the memory buffers can only come from AXI SRAM, QSPI memory, + Flash or the FMC (SDRAM, ...). The internal SRAM1, SRAM2, SRAM3 and SRAM4 is + not supported. SDMMC2 should not have that limitation. See ST AN5200 "Getting + started with STM32H7 Series SDMMC host controller" for more details. |