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docs: provide CN translation for api-reference/peripherals/sdio_slave.rst (Backport v5.1)

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docs/en/api-reference/peripherals/sdio_slave.rst
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@@ -1,91 +1,105 @@
SDIO Card Slave Driver
======================
:link_to_translation:`zh_CN:[中文]`
Overview
--------
.. only:: esp32
The ESP32 SDIO Card peripherals (Host, Slave) shares two sets of pins as below table.
The first set is usually occupied by SPI0 bus which is responsible for the SPI flash holding the code to run.
This means SDIO slave driver can only runs on the second set of pins while SDIO host is not using it.
The ESP32 SDIO Card host and slave peripherals share two sets of pins, as shown in the table below. The first set is usually occupied by the SPI0 bus, which is responsible for the SPI flash holding the code to run. This means the SDIO slave driver can only run on the second set of pins while the SDIO host is not using it.
The SDIO slave can run under 3 modes: SPI, 1-bit SD and 4-bit SD modes, which
is detected automatically by the hardware. According to the SDIO
specification, CMD and DAT0-3 lines should be pulled up no matter in 1-bit,
4-bit or SPI mode.
The SDIO slave can run under three modes: SPI, 1-bit SD, and 4-bit SD modes. Based on the signals on the interface, the device can determine the current mode and configure itself to adapt to that mode. Later, the slave driver can communicate with the slave device to properly handle commands and data transfers. According to the SDIO specification, the CMD and DAT0-3 signal lines should be pulled up whether in 1-bit SD, 4-bit SD or SPI mode.
Connections
^^^^^^^^^^^
.. only:: esp32
+----------+---------------+-------+-------+
| Pin Name | Corresponding | Slot1 | Slot2 |
+ + pins in SPI +-------+-------+
| | mode | GPIO Number |
+==========+===============+=======+=======+
| CLK | SCLK | 6 | 14 |
+----------+---------------+-------+-------+
| CMD | MOSI | 11 | 15 |
+----------+---------------+-------+-------+
| DAT0 | MISO | 7 | 2 |
+----------+---------------+-------+-------+
| DAT1 | Interrupt | 8 | 4 |
+----------+---------------+-------+-------+
| DAT2 | N.C. (pullup) | 9 | 12 |
+----------+---------------+-------+-------+
| DAT3 | #CS | 10 | 13 |
+----------+---------------+-------+-------+
.. list-table::
:header-rows: 1
:widths: 25 25 25 25
:align: center
* - Pin Name
- Corresponding Pins in SPI Mode
- GPIO Number (Slot 1)
- GPIO Number (Slot 2)
* - CLK
- SCLK
- 6
- 14
* - CMD
- MOSI
- 11
- 15
* - DAT0
- MISO
- 7
- 2
* - DAT1
- Interrupt
- 8
- 4
* - DAT2
- N.C. (pullup)
- 9
- 12
* - DAT3
- #CS
- 10
- 13
.. only:: esp32c6
+----------+--------------------------------+---------------+
| Pin Name | Corresponding pins in SPI mode | GPIO Number |
+==========+================================+===============+
| CLK | SCLK | 19 |
+----------+--------------------------------+---------------+
| CMD | MOSI | 18 |
+----------+--------------------------------+---------------+
| DAT0 | MISO | 20 |
+----------+--------------------------------+---------------+
| DAT1 | Interrupt | 21 |
+----------+--------------------------------+---------------+
| DAT2 | N.C. (pullup) | 22 |
+----------+--------------------------------+---------------+
| DAT3 | #CS | 23 |
+----------+--------------------------------+---------------+
.. list-table::
:header-rows: 1
:widths: 30 40 30
:align: center
- 1-bit SD mode: Connect CLK, CMD, DAT0, DAT1 pins and the ground.
- 4-bit SD mode: Connect all pins and the ground.
- SPI mode: Connect SCLK, MOSI, MISO, Interrupt, #CS pins and the ground.
* - Pin Name
- Corresponding Pins in SPI Mode
- GPIO Number
* - CLK
- SCLK
- 19
* - CMD
- MOSI
- 18
* - DAT0
- MISO
- 20
* - DAT1
- Interrupt
- 21
* - DAT2
- N.C. (pullup)
- 22
* - DAT3
- #CS
- 23
.. note:: Please check if CMD and DATA lines D0-D3 of the card are properly
pulled up by 10 KOhm resistors. This should be ensured even in 1-bit mode
or SPI mode. Most official modules don't offer these pullups internally.
If you are using official development boards, check
:ref:`compatibility_overview_espressif_hw_sdio` to see whether your
development boards have such pullups.
- 1-bit SD mode: Connect CLK, CMD, DAT0, DAT1 pins, and the ground.
- 4-bit SD mode: Connect all pins, and the ground.
- SPI mode: Connect SCLK, MOSI, MISO, Interrupt, #CS pins, and the ground.
.. note::
Please check if CMD and DATA lines DAT0-DAT3 of the card are properly pulled up by 10 KOhm - 90 KOhm resistors, which should be ensured even in 1-bit mode or SPI mode. Most official modules do not offer these pullups internally. If you are using official development boards, check :ref:`compatibility_overview_espressif_hw_sdio` to see whether your development boards have such pullups.
.. only:: esp32
.. note:: Most official modules have conflicts on strapping pins with the
SDIO slave function. If you are using a ESP32 module with 3.3 V flash
inside, you have to burn the EFUSE when you are developing on the module
for the first time. See :ref:`compatibility_overview_espressif_hw_sdio` to
see how to make your modules compatible with the SDIO.
.. note::
Here is a list for modules/kits with 3.3 V flash:
Most official modules have conflicts on strapping pins with the SDIO slave function. If you are using an ESP32 module with 3.3 V flash inside, when you are developing on the module for the first time, you will need to perform an eFuse burn-in prior to development. This will adjust the pin configuration of the module to make the module compatible with SDIO functionality. See :ref:`compatibility_overview_espressif_hw_sdio` for details on how to configure this.
- Modules: ESP32-PICO-D4, ESP32-WROOM-32 series (including ESP32-SOLO-1),
ESP32-WROVER-B and ESP32-WROVER-IB
- Kits: ESP32-PICO-KIT, ESP32-DevKitC (till v4), ESP32-WROVER-KIT
(v4.1 (also known as ESP32-WROVER-KIT-VB), v2, v1 (also known as DevKitJ
v1))
Here is a list of modules/kits with 3.3 V flash:
You can tell the version of your ESP23-WROVER-KIT version from the module
on it: v4.1 are with ESP32-WROVER-B modules, v3 are with ESP32-WROVER
modules, while v2 and v1 are with ESP32-WROOM-32 modules.
- Modules: All modules except ESP32-WROVER、ESP32-WROVER-I、ESP32-S3-WROOM-2, and please check `Modules Overview <https://www.espressif.com/en/products/modules>`__ for module list
- Kits: ESP32-PICO-KIT, ESP32-DevKitC (up to v4), ESP32-WROVER-KIT (v4.1 [also known as ESP32-WROVER-KIT-VB], v2, v1 [also known as DevKitJ v1])
You can tell the version of your ESP23-WROVER-KIT version from the module on it: v4.1 are with ESP32-WROVER-B modules, v3 are with ESP32-WROVER modules, while v2 and v1 are with ESP32-WROOM-32 modules.
Refer to :doc:`sd_pullup_requirements` for more technical details of the pullups.
@@ -94,69 +108,52 @@ Refer to :doc:`sd_pullup_requirements` for more technical details of the pullups
sd_pullup_requirements
The host initialize the slave into SD mode by first sending CMD0 with DAT3
pin high, or in SPI mode by sending CMD0 with CS pin (the same pin as DAT3)
low.
The host initializes the slave into SD mode by sending the CMD0 command with the DAT3 pin set to a high level. Alternatively, the host initializes the SPI mode by sending CMD0 with CS pin low, which is the same pin as DAT3.
After the initialization, the host can enable the 4-bit SD mode by writing
CCCR register 0x07 by CMD52. All the bus detection process are handled by the
slave peripheral.
After the initialization, the host can enable the 4-bit SD mode by writing CCCR register 0x07 by CMD52. All the bus detection processes are handled by the slave peripheral.
The host has to communicate with the slave by an ESP-slave-specific protocol.
The slave driver offers 3 services over Function 1 access by CMD52 and CMD53:
(1) a sending FIFO and a receiving FIFO, (2) 52 8-bit R/W registers shared by
host and slave, (3) 16 interrupt sources (8 from host to slave, and 8 from
slave to host).
The slave driver offers three services over Function 1 access by CMD52 and CMD53:
(1) sending and receiving FIFO
(2) 52 R/W registers (8-bit) shared by host and slave
(3) 16 interrupt sources (8 from host to slave, and 8 from slave to host)
Terminology
^^^^^^^^^^^
The SDIO slave driver uses the following terms:
- Transfer: a transfer is always started by a command token from the host, and may contain a reply and several data
blocks. {IDF_TARGET_NAME} SDIO slave software is based on transfers.
- A transfer is initiated by a command token from the host and may consist of a response and multiple data blocks. The core mechanism of the {IDF_TARGET_NAME} SDIO slave driver involves data exchange and communication through transfers.
- Sending: slave to host transfers.
- Receiving: host to slave transfers.
.. note:: Register names in *{IDF_TARGET_NAME} Technical Reference Manual* > *SDIO Slave Controller*
[`PDF <{IDF_TARGET_TRM_EN_URL}#sdioslave>`__] are oriented from the point of view of the host, i.e. 'rx'
registers refer to sending, while 'tx' registers refer to receiving. We're not using `tx` or `rx` in the driver to
avoid ambiguities.
.. note::
- FIFO: specific address in Function 1 that can be access by CMD53 to read/write large amount of data. The address is
related to the length requested to read from/write to the slave in a single transfer:
*requested length* = 0x1F800-address.
- Ownership: When the driver takes ownership of a buffer, it means the driver can randomly read/write the buffer
(usually via DMA). The application should not read/write the buffer until the ownership is returned to the
application. If the application reads from a buffer owned by a receiving driver, the data read can be random; if
the application writes to a buffer owned by a sending driver, the data sent may be corrupted.
The register names in **{IDF_TARGET_NAME} Technical Reference Manual** > **SDIO Slave Controller** [`PDF <{IDF_TARGET_TRM_EN_URL}#sdioslave>`__] are organized from the host's perspective. For instance, ``RX`` registers indicate sending, while ``TX`` registers denote receiving. In our driver implementation, we've chosen not to utilize the terms ``TX`` or ``RX`` to prevent any potential ambiguities.
- FIFO: A designated address within Function 1 that can be accessed using CMD53 commands for reading or writing substantial volumes of data. The address corresponds to the length intended for reading from or writing to the slave in a single transfer: **requested length** = 0x1F800 – address.
- Ownership: When the driver assumes ownership of a buffer, it means that the driver has the capability to perform random read/write operations on the buffer (often via DMA). The application should not read/write the buffer until the ownership is returned to the application. If the application reads from a buffer owned by a receiving driver, the data read can be random; similarly, if the application writes to a buffer owned by a sending driver, the data sent may be corrupted.
- Requested length: The length requested in one transfer determined by the FIFO address.
- Transfer length: The length requested in one transfer determined by the CMD53 byte/block count field.
.. note:: Requested length is different from the transfer length. {IDF_TARGET_NAME} SDIO slave DMA base on the *requested length* rather
than the *transfer length*. The *transfer length* should be no shorter than the *requested length*, and the rest
part will be filled with 0 (sending) or discard (receiving).
.. note::
- Receiving buffer size: The buffer size is pre-defined between the host and the slave before communication starts.
Slave application has to set the buffer size during initialization by the ``recv_buffer_size`` member of
``sdio_slave_config_t``.
- Interrupts: the {IDF_TARGET_NAME} SDIO slave support interrupts in two directions: from host to slave (called slave interrupts below)
and from slave to host (called host interrupts below). See more in :ref:`interrupts`.
- Registers: specific address in Function 1 access by CMD52 or CMD53.
Requested length is different from the transfer length. In the context of {IDF_TARGET_NAME} SDIO slave DMA, the operation is based on the **requested length** rather than the **transfer length**. This means the DMA controller will process the data transfer according to the **requested length**, ensuring that only data within the **requested length** is transferred. The **transfer length** should be no shorter than the **requested length**, and the rest part is filled with 0 during sending or discard during receiving.
- Receiving buffer size: The buffer size is pre-defined between the host and the slave before communication starts. The slave application has to set the buffer size during initialization by the ``recv_buffer_size`` parameter in the ``sdio_slave_config_t`` structure.
- Interrupts: The {IDF_TARGET_NAME} SDIO slave supports interrupts in two directions: from host to slave (referred to as slave interrupts) and from slave to host (referred to as host interrupts). For more details, refer to :ref:`interrupts`.
- Registers: Specific addresses in Function 1 accessed by CMD52 or CMD53.
Communication with ESP SDIO Slave
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The host should initialize the {IDF_TARGET_NAME} SDIO slave according to the standard
SDIO initialization process (Sector 3.1.2 of `SDIO Simplified
Specification <https://www.sdcard.org/downloads/pls/>`_), which is described
briefly in :ref:`esp_slave_init`.
The host should initialize the {IDF_TARGET_NAME} SDIO slave according to the standard SDIO initialization process (Sector 3.1.2 of `SDIO Simplified Specification <https://www.sdcard.org/downloads/pls/pdf/?p=PartE1_SDIO_Simplified_Specification_Ver3.00.jpg&f=PartE1_SDIO_Simplified_Specification_Ver3.00.pdf&e=EN_SSE1>`_), which is described briefly in :ref:`esp_slave_init`.
Furthermore, there's an {IDF_TARGET_NAME}-specific upper-level communication protocol upon the CMD52/CMD53 to
Func 1. Please refer to :ref:`esp_slave_protocol_layer`. There is also a component
:doc:`ESP Serial Slave Link </api-reference/protocols/esp_serial_slave_link>`
for {IDF_TARGET_NAME} master to communicate with {IDF_TARGET_NAME} SDIO slave, see example :example:`peripherals/sdio`
when programming your host.
Furthermore, there is an {IDF_TARGET_NAME}-specific upper-level communication protocol built upon the foundation of CMD52/CMD53 to Function 1. Within this particular communication protocol, the master and slave engage in data exchange and communication through the utilization of CMD52/CMD53 commands. For more detailed information, please consult the :ref:`esp_slave_protocol_layer` section.
There is also a component :doc:`/api-reference/protocols/esp_serial_slave_link` designed for {IDF_TARGET_NAME} master to communicate with {IDF_TARGET_NAME} SDIO slave. See example :example:`peripherals/sdio` when programming your host.
.. _interrupts:
@@ -169,92 +166,78 @@ There are interrupts from host to slave, and from slave to host to help communic
Slave Interrupts
""""""""""""""""
The host can interrupt the slave by writing any one bit in the register 0x08D. Once any bit of the register is
set, an interrupt is raised and the SDIO slave driver calls the callback function defined in the ``slave_intr_cb`` member
in the ``sdio_slave_config_t`` structure.
The host can trigger an interruption in the slave by writing a single bit to the 0x08D register. As soon as any bit within the register is set, an interrupt is generated, prompting the SDIO slave driver to invoke the callback function specified in the ``slave_intr_cb`` member of the ``sdio_slave_config_t`` structure.
.. note:: The callback function is called in the ISR, do not use any delay, loop or spinlock in the callback.
.. note::
There's another set of functions can be used. You can call ``sdio_slave_wait_int`` to wait for an interrupt within a
certain time, or call ``sdio_slave_clear_int`` to clear interrupts from host. The callback function can work with the
wait functions perfectly.
The callback function is called in the ISR. Do not use any delay, loop or blocking function in the callback, e.g. mutex.
Similar to the previous information, there's an alternative set of functions available. You can call ``sdio_slave_wait_int`` to wait for an interrupt within a certain time, or call ``sdio_slave_clear_int`` to clear interrupts from host. The callback function can work with the wait functions perfectly.
Host Interrupts
"""""""""""""""
The slave can interrupt the host by an interrupt line (at certain time) which is level sensitive. When the host see the
interrupt line pulled down, it may read the slave interrupt status register, to see the interrupt source. Host can clear
interrupt bits, or choose to disable a interrupt source. The interrupt line will hold active until all the sources are
cleared or disabled.
The slave can interrupt the host by an interrupt line at certain time, which is level-sensitive, i.e., the interrupt signal can be triggered by detecting the level change of the interrupt line. When the host see the interrupt line pulled down, it may read the slave interrupt status register, to see the interrupt source. Host can clear interrupt bits, or choose to disable a interrupt source. The interrupt line holds active until all the sources are cleared or disabled.
There are several dedicated interrupt sources as well as general purpose sources. see ``sdio_slave_hostint_t`` for
more information.
There are several dedicated interrupt sources as well as general-purpose sources. see ``sdio_slave_hostint_t`` for more information.
Shared Registers
^^^^^^^^^^^^^^^^
There are 52 8-bit R/W shared registers to share information between host and slave. The slave can write or read the
registers at any time by ``sdio_slave_read_reg`` and ``sdio_slave_write_reg``. The host can access (R/W) the register by CMD52 or CMD53.
There are 52 R/W shared registers (8-bit) to share information between host and slave. The slave can write or read the registers at any time by ``sdio_slave_read_reg`` and ``sdio_slave_write_reg``. The host can access (R/W) the register by CMD52 or CMD53.
Receiving FIFO
^^^^^^^^^^^^^^
When the host is going to send the slave some packets, it has to check whether the slave is ready to receive by reading
the buffer number of slave.
When the host is going to send the slave some packets, it has to check whether the slave is ready to receive by reading the buffer number of slave.
To allow the host sending data to the slave, the application has to load buffers to the slave driver by the following steps:
1. Register the buffer by calling ``sdio_slave_recv_register_buf``, and get the handle of the registered buffer. The driver
will allocate memory for the linked-list descriptor needed to link the buffer onto the hardware. The size of these buffers should equal to the Receiving buffer size.
1. Register the buffer by calling ``sdio_slave_recv_register_buf``, and get the handle of the registered buffer. The driver allocates memory for the linked-list descriptor needed to link the buffer onto the hardware. The size of these buffers should equal to the Receiving buffer size.
2. Load buffers onto the driver by passing the buffer handle to ``sdio_slave_recv_load_buf``.
3. Get the received data by calling ``sdio_slave_recv`` or ``sdio_slave_recv_packet``. If non-blocking call is needed, set ``wait=0``.
3. Get the received data by calling ``sdio_slave_recv`` or ``sdio_slave_recv_packet``. If a non-blocking call is needed, set ``wait=0``.
The difference between two APIs is that, ``sdio_slave_recv_packet`` gives more information about packet, which can consist of several buffers. When ``ESP_ERR_NOT_FINISHED`` is returned by this API, you should call this API iteratively until the return value is ``ESP_OK``. All the continuous buffers returned with ``ESP_ERR_NOT_FINISHED``, together with the last buffer returned with ``ESP_OK``, belong to one packet from the host. Call ``sdio_slave_recv_get_buf`` to get the address of the received data, and the actual length received in each buffer. The packet length is the sum of received length of all the buffers in the packet.
The difference between two APIs is that, ``sdio_slave_recv_packet`` gives more information about packet, which can consist of several buffers.
If the host never send data longer than the Receiving buffer size, or you don't care about the packet boundary (e.g. the data is only a byte stream), you can call the simpler version ``sdio_slave_recv`` instead.
When ``ESP_ERR_NOT_FINISHED`` is returned by this API, you should call this API iteratively until the return value is ``ESP_OK``. All the continuous buffers returned with ``ESP_ERR_NOT_FINISHED``, together with the last buffer returned with ``ESP_OK``, belong to one packet from the host.
Call ``sdio_slave_recv_get_buf`` to get the address of the received data, and the actual length received in each buffer. The packet length is the sum of received length of all the buffers in the packet.
If the host never send data longer than the Receiving buffer size, or you do not care about the packet boundary (e.g., the data is only a byte stream), you can call the simpler version ``sdio_slave_recv`` instead.
4. Pass the handle of processed buffer back to the driver by ``sdio_recv_load_buf`` again.
.. note:: To avoid overhead from copying data, the driver itself doesn't have any buffer inside, the application is
responsible to offer new buffers in time. The DMA will automatically store received data to the buffer.
.. note::
To minimize data copying overhead, the driver itself does not maintain any internal buffer; it is the responsibility of the application to promptly provide new buffers. The DMA system automatically stores received data into these buffers.
Sending FIFO
^^^^^^^^^^^^
Each time the slave has data to send, it raises an interrupt and the host will request for the packet length. There are
two sending modes:
Each time the slave has data to send, it raises an interrupt, and the host requests the packet length. There are two sending modes:
- Stream Mode: when a buffer is loaded to the driver, the buffer length will be counted into the packet length requested
by host in the incoming communications. Regardless previous packets are sent or not. This means the host can get data
of several buffers in one transfer.
- Packet Mode: the packet length is updated packet by packet, and only when previous packet is sent. This means that the
host can only get data of one buffer in one transfer.
- Stream Mode: When a buffer is loaded into the driver, the buffer length is included into the packet length requested by host in the incoming communications. This is irrespective of whether previous packets have been sent or not. In other words, the length of the newly loaded buffer is included into the length of the packet requested by the host, even if there are previously unsent packets. This enables the host to receive data from several buffers in a single transfer.
- Packet Mode: The packet length is updated packet by packet, and only when previous packet is sent. This means that the host can only get data of one buffer in one transfer.
.. note:: To avoid overhead from copying data, the driver itself doesn't have any buffer inside. Namely, the DMA takes
data directly from the buffer provided by the application. The application should not touch the buffer until the
sending is finished.
.. note::
The sending mode can be set in the ``sending_mode`` member of ``sdio_slave_config_t``, and the buffer numbers can be
set in the ``send_queue_size``. All the buffers are restricted to be no larger than 4092 bytes. Though in the stream
mode several buffers can be sent in one transfer, each buffer is still counted as one in the queue.
To avoid overhead from copying data, the driver itself does not have any buffer inside. Namely, the DMA takes data directly from the buffer provided by the application. The application should not touch the buffer until the sending is finished, so as to ensure that the data is transferred correctly.
The application can call ``sdio_slave_transmit`` to send packets. In this case the function returns when the transfer
is successfully done, so the queue is not fully used. When higher effeciency is required, the application can use the
following functions instead:
The sending mode can be set in the ``sending_mode`` member of ``sdio_slave_config_t``, and the buffer numbers can be set in the ``send_queue_size``. All the buffers are restricted to be no larger than 4092 bytes. Though in the stream mode, several buffers can be sent in one transfer, each buffer is still counted as one in the queue.
The application can call ``sdio_slave_transmit`` to send packets. In this case, the function returns when the transfer is successfully done, so the queue is not fully used. When higher efficiency is required, the application can use the following functions instead:
1. Pass buffer information (address, length, as well as an ``arg`` indicating the buffer) to ``sdio_slave_send_queue``.
If non-blocking call is needed, set ``wait=0``. If the ``wait`` is not ``portMAX_DELAY`` (wait until success),
application has to check the result to know whether the data is put in to the queue or discard.
2. Call ``sdio_slave_send_get_finished`` to get and deal with a finished transfer. A buffer should be kept unmodified
until returned from ``sdio_slave_send_get_finished``. This means the buffer is actually sent to the host, rather
than just staying in the queue.
- If non-blocking call is needed, set ``wait=0``.
- If the ``wait`` is not ``portMAX_DELAY`` (wait until success), application has to check the result to know whether the data is put in to the queue or discard.
2. Call ``sdio_slave_send_get_finished`` to get and deal with a finished transfer. A buffer should be kept unmodified until returned from ``sdio_slave_send_get_finished``. This means the buffer is actually sent to the host, rather than just staying in the queue.
There are several ways to use the ``arg`` in the queue parameter:
1. Directly point ``arg`` to a dynamic-allocated buffer, and use the ``arg`` to free it when transfer finished.
2. Wrap transfer informations in a transfer structure, and point ``arg`` to the structure. You can use the
structure to do more things like::
2. Wrap transfer informations in a transfer structure, and point ``arg`` to the structure. You can use the structure to do more things like::
typedef struct {
uint8_t* buffer;
@@ -278,8 +261,7 @@ There are several ways to use the ``arg`` in the queue parameter:
ESP_LOGI("tag", "(%d) successfully send %d bytes of %p", arg->id, arg->size, arg->buffer);
some_post_callback(arg); //do more things
3. Working with the receiving part of this driver, point ``arg`` to the receive buffer handle of this buffer. So
that we can directly use the buffer to receive data when it's sent::
3. Work with the receiving part of this driver, and point ``arg`` to the receive buffer handle of this buffer, so that we can directly use the buffer to receive data when it is sent::
uint8_t buffer[256]={1,2,3,4,5,6,7,8};
sdio_slave_buf_handle_t handle = sdio_slave_recv_register_buf(buffer);
@@ -292,7 +274,7 @@ There are several ways to use the ``arg`` in the queue parameter:
sdio_slave_send_get_finished((void**)&handle, portMAX_DELAY);
sdio_slave_recv_load_buf(handle);
More about this, see :example:`peripherals/sdio`.
For more about this, see :example:`peripherals/sdio`.
Application Example