Crate stm32h7_sdmmc

Hardware Abstraction Layer for 'Secure' digital input/output MultiMediaCard interface (SDMMC) on the STM32H7.

This crate depends on the GPIO and Clock functionality from stm32h7xx-hal.

SDMMC

The H7 has two SDMMC peripherals, SDMMC1 and SDMMC2.

IO Setup

For high speed signalling (bus clock > 16MHz), the IO speed needs to be increased from the default.

use stm32h7xx_hal::gpio::Speed;

let d0 = d0.set_speed(Speed::VeryHigh);

Usage

By default the SDMMC bus clock is derived from the pll1_q_ck. This can be set when initialising the RCC.

let ccdr = rcc
    .pll1_q_ck(100.mhz())
    .freeze(vos, &dp.SYSCFG);

There is an extension trait implemented for the SDMMC1 and SDMMC2 periperhals for easy initialisation.

// Create SDMMC
let mut sdmmc = dp.SDMMC1.sdmmc(
    (clk, cmd, d0, d1, d2, d3),
    ccdr.peripheral.SDMMC1,
    &ccdr.clocks,
);

The next step is to initialise a card. The bus speed is also set.

if let Err(err) = sdmmc.init_card(10.mhz()) {
    info!("Init err: {:?}", err);
}

The card() method returns useful information about the card.

let card = sdmmc.card();
if let Some(card) = sdmmc.card() {
    info!("SD Card Connected: {:?}", card);
}

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Structs

CID	Card Identification Register (CID)
CSD	Card Specific Data (CSD)
Card	SD Card
OCR	Operation Conditions Register (OCR)
SCR	SD CARD Configuration Register (SCR)
SDStatus	SD Status
Sdmmc	Sdmmc device

Enums

BusWidth	The number of lines used on the SDMMC bus
CardType	Types of SD Card
Error	Errors
Signalling	The signalling scheme used on the SDMMC bus

Traits

SdmmcExt

Extension trait for SDMMC peripherals