Module sdmmc 

Available on crate feature unstable only.

Secure Digital / MultiMedia Card host (SDMMC / SDIO)

Overview

Driver for the SDMMC/SDIO host controller (SDHOST). The controller exposes up to two independent card slots that share a single transfer engine.

Blocking engine operations return BlockingError; BlockingError::Busy if another slot or an async transfer holds the engine. Async ops await the engine mutex instead. Bus width and card clock are cached and applied on engine acquire (lock order: engine, then settings).

Configuration

SdHostController::new takes a Config for the shared module clock. Each slot is obtained via SdHostController::slot with a SlotConfig, then wired with with_clk, with_cmd, with_data*, and optional card-detect / write-protect pins.

Usage

Blocking commands and block transfers are available on Slot in Blocking mode. Slot::into_async enables interrupt-driven operation and implements sdio::MmcBus for the sdio crate stack.

Implementation State

SDIO device (I/O) mode is supported via sdio::MmcBus. SPI mode and UHS-I (1.8 V switching) are not implemented.

Structs

CommandFlags

Per-command engine flags.

Config

Controller-wide (engine) configuration.

SdHostController

SDMMC / SDIO host controller driver.

Slot

A configured card slot, generic over the slot index and driver mode.

SlotConfig

Per-slot configuration.

Enums

BlockingError

Error from blocking engine operations (BlockingError::Busy is mutex contention, not CIU HLE).

BusWidth

Card data bus width.

ClockSource

Card clock source feeding the controller’s divider.

ConfigError

Error returned when applying a Config.

Error

Error returned by host operations.

ResponseLen

Length of the response a command expects.

SlotId

Selects one of the controller’s card slots.

Traits

SlotClk

Card-clock output pin for slot S.

SlotCmd

Command (bidirectional) pin for slot S.

SlotData

Data line L (bidirectional) for slot S.