SD card driver public API. More...

#include "err.h"
#include "stm32f401re.h"
#include "stm32f401re_gpio.h"
#include "configuration.h"

Include dependency graph for sd.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	SD_CFG_ts
	Configuration structure for initializing an SD card handle. More...

Typedefs
typedef struct sd_handle_s	SD_HANDLE_ts
	Opaque handle representing an SD card instance.

Functions
ERR_te	sd_init_subsys (void)
	Initializes the SD card subsystem.
ERR_te	sd_deinit_subsys (void)
	Deinitializes the SD card subsystem.
ERR_te	sd_start_subsys (void)
	Starts the SD card subsystem.
ERR_te	sd_stop_subsys (void)
	Stops the SD card subsystem.
ERR_te	sd_init_handle (SD_CFG_ts sd_cfg, SD_HANDLE_ts *sd_handle_o)
	Initializes an SD card handle and performs the full SPI-mode power-up sequence.
ERR_te	sd_deinit_handle (SD_HANDLE_ts *sd_handle)
	Deinitializes an SD card handle and resets the SPI peripheral.
ERR_te	sd_get_handle_init (SD_HANDLE_ts sd_handle, bool handle_init_o)
	Retrieves the initialization state of an SD card handle.
ERR_te	sd_get_sector_count (SD_HANDLE_ts sd_handle, uint32_t sector_count_o)
	Retrieves the total sector (block) count of the SD card.
ERR_te	sd_get_sector_size (SD_HANDLE_ts sd_handle, uint32_t sector_size_o)
	Retrieves the sector (block) size of the SD card in bytes.
ERR_te	sd_read (SD_HANDLE_ts sd_handle, uint8_t read_buf, uint32_t start_sector, uint32_t num_sectors)
	Reads one or more sectors from the SD card.
ERR_te	sd_write (SD_HANDLE_ts sd_handle, uint8_t write_buf, uint32_t start_sector, uint32_t num_sectors)
	Writes one or more sectors to the SD card.
ERR_te	sd_ioctl (SD_HANDLE_ts *sd_handle)
	Executes an IOCTL control command on the SD card handle.

Detailed Description

SD card driver public API.

Author: github.com/Baksi675

This module provides an SPI-based SD card driver supporting SDSC and SDHC cards in SPI mode. It handles card initialization, type detection, CSD register parsing, and sector-level read/write operations. The driver is designed to be used as the low-level backend for a FatFs diskio layer.

Card initialization in sd_init_handle performs the full SPI-mode power-up sequence:

Sends at least 74 dummy clock cycles with CS high
Issues CMD0 to enter idle state
Issues CMD8 to detect SD Ver.2 vs Ver.1 / MMC
Issues ACMD41 or CMD1 to complete initialization
Reads the OCR and CSD registers to determine capacity and addressing mode
Ramps the SPI clock to maximum speed after initialization

Typical usage:

Initialize the subsystem using sd_init_subsys
Populate an SD_CFG_ts and register a handle with sd_init_handle
Start the subsystem using sd_start_subsys
Use sd_read and sd_write for sector-level access
Query card properties with sd_get_sector_count and sd_get_sector_size

Version: 0.1

Date: 2026-02-05

Definition in file sd.h.

Classes

Typedefs

Functions

Detailed Description