SD/MMC Driver and SDIO Driver

Table of Contents

• SDMMC HAL Module Introduction
  • SDMMC HAL Module Features
  • SDMMC Hardware Support Details
• SDMMC HAL Module APIs Overview
• SDMMC HAL Module Operational Overview
  • SDMMC HAL Module Important Operational Notes and Limitations
    • SDMMC HAL Module Operational Notes
    • SDMMC HAL Module Limitations
• Including the SDMMC HAL Module in an Application
• Configuring the SDMMC HAL Module
  • Configuration Settings for the SDMMC HAL Module Lower Level Modules
  • SDMMC HAL Module Clock Configuration
  • SDMMC HAL Module Pin Configuration
• Using the SDMMC HALModule in an Application

SDMMC HAL Module Introduction

The SDMMC (SD/MMC and SDIO) HAL module is used to read/write and control SDMMC media devices and SDIO cards. The SDMMC module can be used as a standalone SD card, eMMC or media driver, or it can be used with FileX and other compatible file systems. The SDMMC HAL module uses the SDMMC peripheral on the Synergy MCU.

SDMMC HAL Module Features

• Supports the following memory devices: SDSC (SD Standard Capacity), SDHC (SD High Capacity), SDXC (SD Extended Capacity) and eMMC (embedded Multi Media Card)
  • Supports reading, writing and erasing SD and eMMC memory devices
  • Supports 1, 4 or 8-bit data busses (8-bit bus is supported for eMMC only)
  • Supports detection of hardware write protection (SD cards only)
  • Automatically selects between backwards compatible mode and high speed SRD mode (eMMC)
• Supports SDIO
  • Supports SDIO single register access (CMD52)
  • Supports SDIO multiple register access (CMD53)
  • Supports SDIO interrupts
  • Automatically configures the clock to the maximum clock rate supported by both host (MCU) and device

SDMMC HAL Module Block Diagram

SDMMC Hardware Support Details

Legend:

Symbol	Meaning
✓	Available (Tested)
⌧	Not Available (Not tested/not functional or both)
N/A	Not supported by MCU

 

MCU Group	SD 1 bit	SD 4 bit	SDHC	SDXC	MMC 1 bit	MMC 4 bit
S124	N/A	N/A	N/A	N/A	N/A	N/A
S128	N/A	N/A	N/A	N/A	N/A	N/A
S1JA	N/A	N/A	N/A	N/A	N/A	N/A
S3A1	✓	✓	✓	✓	⌧	⌧
S3A3	✓	✓	✓	✓	⌧	⌧
S3A6	N/A	N/A	N/A	N/A	N/A	N/A
S3A7	✓	✓	✓	✓	⌧	⌧
S5D3	✓	✓	✓	✓	⌧	⌧
S5D5	✓	✓	✓	✓	⌧	⌧
S5D9	✓	✓	✓	✓	⌧	⌧
S7G2	✓	✓	✓	✓	⌧	✓

MCU Group	MMC 8 bit	MMC Backward Compatibility Mode	Card Detect: Insertion	Card Detect: Removal	Write Protect	MMC High Speed SDR Mode
S124	N/A	N/A	N/A	N/A	N/A	N/A
S128	N/A	N/A	N/A	N/A	N/A	N/A
S1JA	N/A	N/A	N/A	N/A	N/A	N/A
S3A1	⌧	⌧	⌧	⌧	✓	⌧
S3A3	⌧	⌧	⌧	⌧	✓	⌧
S3A6	N/A	N/A	N/A	N/A	N/A	N/A
S3A7	⌧	⌧	⌧	⌧	✓	⌧
S5D3	⌧	⌧	See note	See note	✓	⌧
S5D5	⌧	⌧	See note	See note	✓	⌧
S5D9	⌧	⌧	See note	See note	✓	⌧
S7G2	✓	⌧	See note	See note	✓	✓

 Note: Available on some of the MCUs (for the group indicated in the table) based on the pin map.

MCU Group	DMA Read	DMA Write	Single Block Read	Single Block Write	IO RW Direct	IO RW Extended
S124	N/A	N/A	N/A	N/A	N/A	N/A
S128	N/A	N/A	N/A	N/A	N/A	N/A
S1JA	N/A	N/A	N/A	N/A	N/A	N/A
S3A1	✓	✓	✓	✓	✓	✓
S3A3	✓	✓	✓	✓	✓	✓
S3A6	N/A	N/A	N/A	N/A	N/A	N/A
S3A7	✓	✓	✓	✓	✓	✓
S5D3	✓	✓	✓	✓	✓	✓
S5D5	✓	✓	✓	✓	✓	✓
S5D9	✓	✓	✓	✓	✓	✓
S7G2	✓	✓	✓	✓	✓	✓

SDMMC HAL Module APIs Overview

The SDMMC HAL module defines API functions including opening, reading, writing and closing. A complete list of the available API functions, an example API function call and a short description of each can be found in the following table. A table of status return values follows the API summary table.

SDMMC HAL Module API Summary

Function Name	Example API Call and Description
open	g_sdmmc.p_api->open(g_sdmmc.p_ctrl, g_sdmmc.p_cfg); Open device channel for read/write and control. Initialize driver and hardware on first call.
read	g_sdmmc.p_api->read(g_sdmmc.p_ctrl, &destination, start, count); Read data from SD/MMC channel.
write	g_sdmmc.p_api->write(g_sdmmc.p_ctrl, &source, start, count); Write data to SDMMC channel.
control	g_sdmmc.p_api->control(g_sdmmc.p_ctrl, command, &data); Send control commands to the SD/MMC port and receive the status of the SD/MMC port.
close	g_sdmmc.p_api->close(g_sdmmc.p_ctrl); Close open SDMMC channel. Turns off hardware if last channel open.
versionGet	g_sdmmc.p_api->versionGet(&version); Get version of Block Media SD/MMC driver.
readIo	g_sdmmc.p_api->readIo(g_sdmmc.p_ctrl, &data, function, address); Read I/O data from an SDMMC channel.
writeIo	g_sdmmc.p_api->writeIo(g_sdmmc.p_ctrl, &data, function, address, read_after_write); Write I/O data to SDMMC channel.
readIoExt	g_sdmmc.p_api->readIoExt(g_sdmmc.p_ctrl, &destination, function, address, count, transfer_mode, address_mode); Read I/O data, extended, from an SDMMC channel.
writeIoExt	g_sdmmc.p_api->writeIoExt(g_sdmmc.p_ctrl, &source, function, address, count, transfer_mode, address_mode); Write I/O data, extended, to SDMMC channel.
IoIntEnable	g_sdmmc.p_api->IoIntEnable(g_sdmmc.p_ctrl, enable); Enables SDIO interrupt for SDMMC channel.
infoGet	g_sdmmc.p_api->infoGet(g_sdmmc.p_ctrl, &info); Get SDMMC channel info.
erase	g_sdmmc.p_api->erase(g_sdmmc.p_ctrl, start, count); Erase SDMMC sectors.

Note

For more complete descriptions of operation and definitions for the function data structures, typedefs, defines, API data, API structures, and function variables, review the SSP User's Manual API References for the associated module.

Status Return Values

Name	Description
SSP_SUCCESS	API Call Successful.
SSP_ERR_INVALID_ARGUMENT	Parameter has invalid value.
SSP_ERR_IN_USE	The channel specified has already been opened. No configurations were changed. Call the associated Close function or use associated Control commands to reconfigure the channel.
SSP_ERR_ASSERTION	The pointer is NULL.
SSP_ERR_WRITE_PROTECTED	SD or MMC card is Write Protected.
SF_INFO_NOT_AVAILABLE	Information not available possibly because card has been removed or is defective.
SSP_ERR_NOT_OPEN	The channel is not opened.
SSP_ERR_HW_LOCKED	The hardware lock has already been acquired.
SSP_ERR_TRANSFER_BUSY	The transfer is in progress.
SSP_ERR_CARD_NOT_READY	The card is not ready yet.
SSP_ERR_NOT_ENABLED	SDIO interrupt enable failed.
SSP_ERR_READ_FAILED	Read operation failed.
SSP_ERR_WRITE_FAILED	Write operation failed.

Note

Lower-level drivers may return common error codes. Refer to the SSP User's Manual API References for the associated module for a definition of all relevant status return values.

SDMMC HAL Module Operational Overview

The following descriptions cover the operational functions and requirements when using the SDMMC HAL module:

Interrupt Configurations:

Using SD/MMC with DTC:

• Access Interrupt
• DTC Interrupt

Using SD/MMC with DMAC:

• Access Interrupt
• DMAC Interrupt (in DMAC instance)

Using SDIO with DTC:

• Access Interrupt
• SDIO Interrupt
• DTC Interrupt

Using SDIO with DMAC:

• Access Interrupt
• SDIO Interrupt
• DMAC Interrupt (in DMAC instance)

The Card interrupt is optional and only available on MCU packages that have the SDHIn CD pin (n = channel number) available on the Pins tab of the Synergy Configuration tool.

Block Size Configuration

Block size configuration is provided for use with SDIO cards only.  For SDIO cards, block size may be configured to 1-512 bytes.  Block size must remain at the default 512 bytes for SD cards and e/MMC memory devices.

Card Detection Configuration

See Card Detection Limitations before using card detection in the SDMMC HAL driver.  If card detection is not available or not desired for the application, Card Detection must be set to Not Used in the Properties for the r_sdmmc instance in the Synergy Configuration tool.  To enable card detection, set Card Detection to CD Pin and Media Type to Card in the Properties for the r_sdmmc instance in the Synergy Configuration tool.

Access Interrupt Priority

When data transfers are not 4-byte aligned or not a multiple of 4 bytes, a software copy of the block size (up to 512 bytes) is done in the access interrupt.  This blocks other interrupts that are a lower or equal priority to the access interrupt until the software copy is complete.

General Timing Notes

Several functions in this driver block. sdmmc_api_t::open() and sdmmc_api_t::erase() block until the entire operation is complete.  sdmmc_api_t::read(), sdmmc_api_t::write(), sdmmc_api_t::readIo(), sdmmc_api_t::writeIo(), sdmmc_api_t::readIoExt(), and sdmmc_api_t::writeIoExt() block for a single command response cycle.  In a multithreaded system, care should be taken to use this driver in a lower priority thread if other threads require a response time faster than the time this driver could block for during one of these function calls.

Timing Notes for Open

The sdmmc_api_t::open() API completes the entire device identification and configuration process.  This involves several command-response cycles at a bus width of 1-bit and a bus speed of 400 kHz or less.

Timing Notes for Read, Write, ReadIoExtand WriteIoExt

The read and write media (sdmmc_api_t::read() and sdmmc_api_t::write()) and extended read and write SDIO APIs (sdmmc_api_t::readIoExt() and sdmmc_api_t::writeIoExt()) block until the response is received from the device. The data transfer operation is non-blocking and requires interrupts and a transfer instance, either DMAC or DTC. These APIs return SSP_SUCCESS to indicate that the initial operations have started successfully. The application must wait for a callback with the event SDMMC_EVENT_TRANSFER_COMPLETE or SDMMC_EVENT_TRANSFER_ERROR to indicate completion of the read or write.

Timing Notes for ReadIo and WriteIo

The SDIO sdmmc_api_t::readIo() and sdmmc_api_t::writeIo() APIs block until the response is received from the device.  The read or write operation is complete when these APIs return.

Timing Notes for Erase

The sdmmc_api_t::erase() API blocks until the erase operation is complete.  This may be several seconds or more depending on how many sectors are being erased.

SDIO Interrupts

Many SDIO cards use level interrupts, meaning the interrupt is not de-asserted until the interrupt is cleared on the device.  In order to ensure SDIO interrupts are cleared appropriately, one of the following methods are recommended:

• Ensure the SDIO interrupt is cleared on the device before exiting the callback function with the event SDMMC_EVENT_SDIO.  If this method is chosen and any SDIO API must be used in the interrupt, the access interrupt must be a higher priority than the SDIO interrupt.
• Disable the SDIO interrupt in the callback function with the event SDMMC_EVENT_SDIO using sdmmc_api_t::IoIntEnable().  Clear the SDIO interrupt elsewhere in the application, then re-enable SDIO interrupts if desired using sdmmc_api_t::IoIntEnable().

SDMMC HAL Module Important Operational Notes and Limitations

SDMMC HAL Module Operational Notes

SD HALA Compliance

When developing host devices that are compliant with the SD Specifications, the host must comply with the SD Host/Ancillary Product License Agreement (SD HALA).

SDMMC HAL Module Limitations

Data Alignment and Size

Data transfers should be 4-byte aligned and a multiple of 4 bytes in size whenever possible.  This recommendation applies to the read(), write(), readIoExt(), and writeIoExt() APIs.  When data transfers are 4-byte aligned and a multiple of 4-bytes, the r_sdmmc driver is zero copy and takes full advantage of hardware acceleration by the DMAC or DTC.  When data transfers are not 4-byte aligned or not a multiple of 4 bytes an extra CPU interrupt is required for each block transferred (see Access Interrupt Priority).

Card Detection Limitations

Card detection support in the r_sdmmc driver is limited.  Card detection is only available after sdmmc_api_t::open() is complete, and open() cannot be completed unless a card is inserted.  Card detection in the r_sdmmc driver is therefore only useful to detect card removal and reinsertion.  After reinsertion is detected, the driver must be closed and reopened, and card detection will not be available until the reopen is complete.  Card detection is available only on MCU packages that have the SDHIn CD pin (n = channel number) available on the Pins tab of the Synergy Configuration Tool.  If the MCU does not have the SDHIn CD pin, or card detection is not desired for the application, card detection must be disabled in the Properties for the r_sdmmc instance in the Synergy Configuration Tool.  An alternative to using the card detection feature of the r_sdmmc driver is to use an External IRQ instance and handle card detection at the application layer. If card detection is handled at the application layer, the sdmmc_api_t::open() should be called after card insertion is detected, and the sdmmc_api_t::close() should be called after card removal is detected.

Refer to the most recent SSP Release notes for the most up to date limitations for this module.

Including the SDMMC HAL Module in an Application

This section describes how to include the SDMMC HAL Module in an application using the SSP configurator.

Note

This section assumes you are familiar with creating a project, adding threads, adding a stack to a thread and configuring a block within the stack. If you are unfamiliar with any of these items, refer to the first few chapters of the SSP User's Manual to learn how to manage each of these important steps in creating SSP-based applications.

To add the SD/MMC Driver to an application, simply add it to a thread using the stacks selection sequence given in the following table. (The default name for the SD/MMC Driver is g_sdmmc0. This name can be changed in the associated Properties window.)

SDMMC HAL Module Selection Sequence

Resource	ISDE Tab	Stacks Selection Sequence
g_sdmmc0 SD/MMC driver on r_sdmmc	Threads	New Stack> Driver> Storage> SD/MMC Driver on r_sdmmc

When the SDMMC HAL module on r_sdmmc is added to the thread stack as shown in the following figure, the configurator automatically adds any needed lower‑level modules. Any modules needing additional configuration information have the box text highlighted in Red. Modules with a Gray band are individual modules that stand alone. Modules with a Blue band are shared or common; they need only be added once and can be used by multiple stacks. Modules with a Pink band can require the selection of lower-level modules; these are either optional or recommended. (This is indicated in the block with the inclusion of this text.) If the addition of lower-level modules is required, the module description include Add in the text. Clicking on any Pink banded modules brings up the New icon and displays possible choices.

SDMMC HAL Module Stack

Configuring the SDMMC HAL Module

The SDMMC HAL Module must be configured by the user for the desired operation. The available configuration settings and defaults for all the user-accessible properties are given in the properties tab within the SSP configurator and are shown in the following tables for easy reference. Only properties that can be changed without causing conflicts are available for modification. Other properties are locked and not available for changes and are identified with a lock icon for the locked property in the Properties window in the ISDE. This approach simplifies the configuration process and makes it much less error-prone than previous manual approaches to configuration. The available configuration settings and defaults for all the user-accessible properties are given in the Properties tab within the SSP Configurator and are shown in the following tables for easy reference.

Note

You may want to open your ISDE, create the module and explore the property settings in parallel with looking over the following configuration table settings. This will help orient you and can be a useful 'hands-on' approach to learning the ins and outs of developing with SSP.

ConfigurationSettings for the SDMMC HAL Module on r_sdmmc

ISDE Property	Value	Description
Parameter Checking	BSP, Enabled, Disabled Default: BSP	Enable or disable parameter error checking.
Name	g_sdmmc0	The name to be used for SDMMC module control block instance. This name is also used as the prefix of the other variable instances.
Channel	0	Select the channel.
Media Type	Embedded, Card Default: Embedded	Media is a card or an embedded device. This allows to firmware to know whether to look for card insertion/removal and write protect pins.
Bus Width	1 Bit, 4 Bits, 8 bits Default: 4 Bits	Data bus with as defined by hardware interface. (8 Bits for eMMC only).
Block Size	512	Select the media block size.
Card Detection	Not Used, CD Pin Default: CD Pin	Select the card detection method.
Write Protection	WP Pin, Not Used Default: WP Pin	Select whether or not to use the write protect pin. Select Not Used if the MCU or device does not have a write protect pin.
Callback	NULL	(Required if not using FileX) Set to name of user callback function. Provides event that caused interrupt: SDMMC_EVENT_CARD_REMOVED, SDMMC_EVENT_CARD_INSERTED, SDMMC_EVENT_ACCESS, SDMMC_EVENT_SDIO, SDMMC_EVENT_TRANSFER_COMPLETE, SDMMC_EVENT_TRANSFER_ERROR.
Access Interrupt Priority	Priority 0 (highest), Priority 1:14 Priority 15 (lowest - not valid if using ThreadX) Default: Priority 12	Access interrupt priority selection.
Card Interrupt Priority	Priority 0 (highest), Priority 1:14 Priority 15 (lowest - not valid if using ThreadX), Disabled Default: Disabled	Card interrupt priority selection.
DTC Interrupt Priority	Priority 0 (highest), Priority 1:14 Priority 15 (lowest - not valid if using ThreadX), Disabled Default: Disabled	DTC interrupt priority selection.

Note

The example settings and defaults are for a project using the Synergy S7G2 MCU Group. Other MCUs may have different default values and available configuration settings.

Configuration Settings for the SDMMC HAL Module Lower Level Modules

Typically, only a small number of settings must be modified from the default for lower level drivers as indicated via the red text in the thread stack block. Notice that some of the configuration properties must be set to a certain value for proper framework operation and will be locked to prevent user modification. The following tables identify all the settings within the properties section for the module:

Configuration Settings for the Transfer Driver on r_dmac Software Activation

ISDE Property	Value	Description
Parameter Checking	BSP, Enabled, Disabled Default: BSP	Selects if code for parameter checking is to be included in the build.
Name	g_transfer0	Module name.
Channel	0	Channel selection.
Mode	Normal	Mode selection.
Transfer Size	1 Byte	Transfer size selection.
Destination Address Mode	Fixed	Destination address mode selection.
Source Address Mode	Incremented	Source address mode selection.
Repeat Area (Unused in Normal Mode	Source	Repeat area selection.
Destination Pointer	NULL	Destination pointer selection.
Source Pointer	NULL	Source pointer selection.
Number of Transfers	0	Number of transfers selection.
Number of Blocks (Valid only in Block Mode)	0	Number of blocks selection.
Activation Source (Must enable IRQ)	Software Activation	Activation source selection.
Auto Enable	False	Auto enable selection.
Callback (Only valid with Software start)	NULL	Callback selection.
Interrupt Priority	Priority 0 (highest), Priority 1:14 Priority 15 (lowest - not valid if using ThreadX), Disabled Default: Disabled	Interrupt priority selection.

Note

The example settings and defaults are for a project using the Synergy S7G2 MCU Group. Other MCUs may have different default values and available configuration settings.

Configuration Settings for the Transfer Driver on r_dtc Software Activation 1

ISDE Property	Value	Description
Parameter Checking	BSP, Enabled, Disabled Default: BSP	Selects if code for parameter checking is to be included in the build.
Software Start	Enabled, Disabled Default: Disabled	Software start selection.
Linker section to keep DTC vector table	.ssp_dtc_vector_table	Linker section to keep DTC vector table selection.
Name	g_transfer0	Module name.
Mode	Normal	Mode selection.
Transfer Size	1 Byte	Transfer size selection.
Destination Address Mode	Fixed	Destination address mode selection.
Source Address Mode	Incremented	Source address mode selection.
Repeat Area (Unused in Normal Mode	Source	Repeat area selection.
Interrupt Frequency	After all transfers have completed	Interrupt frequency selection.
Destination Pointer	NULL	Destination pointer selection.
Source Pointer	NULL	Source pointer selection.
Number of Transfers	0	Number of transfers selection.
Number of Blocks (Valid only in Block Mode)	0	Number of blocks selection.
Activation Source (Must enable IRQ)	Software Activation 1	Activation source selection.
Auto Enable	False	Auto enable selection.
Callback (Only valid with Software start)	NULL	Callback selection.
ELC Software Event Interrupt Priority	Priority 0 (highest), Priority 1:14 Priority 15 (lowest - not valid if using ThreadX), Disabled Default: Disabled	ELC Software Event interrupt priority selection.

Note

The example settings and defaults are for a project using the Synergy S7G2 MCU Group. Other MCUs may have different default values and available configuration settings.

SDMMC HAL Module Clock Configuration

The SDMMC MCU peripheral (SDHI) uses the PCLKA for its clock source. There is no need to configure the clock specifically for the SDMMC peripheral unless you need to optimize the data rate. The SDMMC driver selects the appropriate built-in divider based on the PCLKA frequency and the maximum clock rate allowed by the SD, SDIO or eMMC device obtained at media device initialization.

SDMMC HAL Module Pin Configuration

Use the ISDE pin configurator to configure the I/O pins for SDMMC peripheral (SDHI). The drive capacity for each pin should be set to "Medium" or "High" for most boards and high-speed memory and SDIO devices.  The following table illustrates the method for selecting the pins within the SSP configuration window and the subsequent table illustrates an example selection for the pins:

Note

The operation mode selection determines what peripheral signals are available and what MCU pins are required.

Pin Selection Sequence for SDMMC HAL Module on r_riic

Resource	ISDE Tab	Pin selection Sequence
SDHI	Pins	Select Peripherals> Storage:SHDI> SDHI0

Note

The selection sequence assumes SCI1 is the desired hardware target for the driver.

Pin Configuration Settings for the SDHI Peripheral

Pin Configuration Property	Value	Description
Operation Mode	Disabled, Custom, SD_MMC 1 bit SD_MMC 4 bit MMC 8 bit Default: Custom	Select mode as per application.
CLK	None, P413 Default: P413	Clock pin.
CMD	None, P412 Default: P412	Command pin.
DAT0-7	None, PXXX Default: PXXX	Data pin.
CD	None, P903 Default: P903	Card detection pin.
WP	None, P414 Default: P414	Card write protection pin.
SDA	Disabled	SDA Pin (when Simple I2C is used).
SCL	Disabled	SCL Pin (when Simple I2C is used).

Note

The example settings are for a project using the Synergy S7G2 MCU Group and the SK-S7G2 Kit. Other Synergy Kits and other Synergy MCUs may have different available pin configuration settings.

Using the SDMMC HALModule in an Application

The steps for using the SDMMC HAL module in a typical application are:

1. Open the driver using the sdmmc_api_t::open() API.
2. Read data from the card using the sdmmc_api_t::read() API or write data to the card using sdmmc_api_t::write() API.
3. Wait for a callback with the event SDMMC_EVENT_TRANSFER_COMPLETE (meaning the operation completed successfully) or SDMMC_EVENT_TRANSFER_ERROR (meaning the operation did not complete successfully) after each time the sdmmc_api_t::read() API or the sdmmc_api_t::write() API is called.

These common steps are illustrated in a typical operational flow diagram in the following figure:

Flow Diagram of a Typical SDMMC HAL Module Application

The steps for using the SDMMC HAL module with an SDIO card in a typical application are:

1. Open the driver using the sdmmc_api_t::open() API.
2. Set or read back single registers using the sdmmc_api_t::readIo() API or the sdmmc_api_t::writeIo() API.  The operation is complete immediately after these calls and there is no need to wait for a callback.
3. Set or read back multiple registers using the sdmmc_api_t::readIoExt() API or the sdmmc_api_t::writeIoExt() API.  The block size can be changed using the sdmmc_api_t::control() API between calls if necessary.
4. Wait for a callback with the event SDMMC_EVENT_TRANSFER_COMPLETE (meaning the operation completed successfully) or SDMMC_EVENT_TRANSFER_ERROR (meaning the operation did not complete successfully) after each time the sdmmc_api_t::readIoExt() API or the sdmmc_api_t::writeIoExt() API is called.
5. If the card requests an interrupt, the callback is called with the event SDMMC_EVENT_SDIO.  Handle the SDIO interrupt as described in the documentation for the card (see the SDIO Interrupts section of this documentation).  SDIO interrupts from the card can be enabled or disabled at any time using the sdmmc_api_t::IoIntEnable() API.

These common steps are illustrated in a typical operational flow diagram in the following figure:

Flow Diagram of a Typical SDMMC HAL Module Application