Module stm32h7xx_hal::sdmmc[−][src]

SD MultiMediaCard interface (SDMMC)

For HDHC / SDXC / SDUC cards. SDSC cards are not supported.

The H7 has two SDMMC peripherals, SDMMC1 and SDMMC2.

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);

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(pwrcfg, &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);
}

Card	SD Card
Sdmmc	Sdmmc device

Error	Errors
Signalling	The signalling scheme used on the SDMMC bus

PinClk
PinCmd
PinD0
PinD1
PinD2
PinD3
PinD4
PinD5
PinD6
PinD7
Pins
SdmmcExt	Extension trait for SDMMC peripherals