Direct Memory Access#


Introduction#

Direct Memory Access (DMA) is a process of transferring data from one memory location to another without the direct involvement of the processor (CPU). The main benefit of using DMA is more efficient data movement in the embedded system.

Here are some common applications of DMA in microcontroller systems:

  • Data Transfer: One of the primary uses of DMA is to facilitate data transfer between peripherals and memory.

  • Memory-to-Memory Transfer: DMA can also be utilized for moving data between different memory locations, providing fast and efficient memory operations without CPU intervention. This is particularly useful for tasks like memory copying, memory clearing, or memory initialization.

  • Peripheral Initialization: DMA can assist in initializing peripheral registers or buffers by transferring predefined data patterns or configurations directly from memory to the peripheral registers, speeding up the initialization process.

  • Data Processing: DMA can be employed for offloading data processing tasks from the CPU to dedicated hardware peripherals.

  • Real-Time Systems: DMA is essential in real-time systems where predictable and deterministic data transfer is crucial. By minimizing CPU involvement in data transfer operations, DMA helps meet strict timing requirements and reduces the likelihood of missed deadlines in time-critical applications.

  • Power Management: DMA can contribute to power efficiency by reducing CPU wake-up times and allowing the CPU to enter low-power modes more frequently. By handling data transfer tasks autonomously, DMA can help optimize power consumption in battery-operated or energy-constrained systems.


Configuration#

  • Configuring DMA involves three parameters that can be configured. The DMA instance can be configured through the API sl_si91x_dma_init(). The DMA channel can be configured in the range of 1-32 by passing the instance and channel to the API sl_si91x_dma_allocate_channel(). The transfer size can also be configured in the range of 1-10000.

  • For more information on configuring available parameters, see the respective peripheral example readme document.


Usage#

The common DMA functions can be used after the DMA structures are specified, passing an instance of sl_dma_init_t. These functions will initiate and configure the DMA as described below, which is the flow for implementation.

  1. sl_si91x_dma_init : This API initializes the DMA peripheral.

  2. sl_si91x_dma_allocate_channel : This API allocates a DMA channel for the transfer.

  3. sl_si91x_dma_register_callbacks : This API registers the DMA callbacks (transfer complete & error).

  4. sl_si91x_dma_transfer : This API starts the DMA transfer.

  5. sl_si91x_dma_deinit : This function de-initializes the DMA peripheral.

Modules#

sl_dma_callback_t

sl_dma_init_t

sl_channel_data_t

sl_dma_xfer_t

Enumerations#

enum
SL_DMA_MEMORY_TO_MEMORY
SL_DMA_MEMORY_TO_PERIPHERAL
SL_DMA_PERIPHERAL_TO_MEMORY
}

Enumeration to represent DMA transfer types.

enum
SL_DMA_BASIC_MODE = UDMA_MODE_BASIC
SL_DMA_PINGPONG_MODE = UDMA_MODE_PINGPONG
}

Enumeration to represent DMA transfer modes.

enum
SL_USART0_ACK = 0x01
SL_UART1_ACK = 0x02
SL_UART3_ACK = 0x03
SL_SSI_SLAVE_ACK = 0x04
SL_SSI_MASTER_ACK = 0x05
SL_SSI1_SLAVE_ACK = 0x06
SL_I2C_ACK = 0x07
}

Enumeration that holds peripheral ACK signals for DMA.

enum
SL_TRANSFER_SIZE_32 = SRC_SIZE_32
SL_TRANSFER_SIZE_16 = SRC_SIZE_16
SL_TRANSFER_SIZE_8 = SRC_SIZE_8
}

Enumeration that holds DMA transfer sizes.

enum
SL_TRANSFER_SRC_INC_32 = SRC_INC_32
SL_TRANSFER_SRC_INC_16 = SRC_INC_16
SL_TRANSFER_SRC_INC_8 = SRC_INC_8
SL_TRANSFER_SRC_INC_NONE = SRC_INC_NONE
SL_TRANSFER_DST_INC_32 = DST_INC_32
SL_TRANSFER_DST_INC_16 = DST_INC_16
SL_TRANSFER_DST_INC_8 = DST_INC_8
SL_TRANSFER_DST_INC_NONE = DST_INC_NONE
}

Enumeration that holds DMA transfer address increment options for source and destination.

enum
SL_DMA_TRANSFER_DONE_CB = 1
SL_DMA_ERROR_CB = 2
}

Enumeration that holds 8-bit codes used by the callback_type parameter in the sl_si91x_dma_unregister_callbacks function.

Typedefs#

typedef void(*
sl_dma_transfer_complete)(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA transfer completes.

typedef void(*
sl_dma_error)(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA error occurs.

Variables#

Functions#

sl_status_t
sl_si91x_dma_init(sl_dma_init_t *dma_init)

To initialize the DMA peripheral.

sl_status_t
sl_si91x_dma_deinit(uint32_t dma_number)

To de-initialize the DMA peripheral.

sl_status_t
sl_si91x_dma_allocate_channel(uint32_t dma_number, uint32_t *channel_no, uint32_t priority)

To allocate a DMA channel for the transfer.

sl_status_t
sl_si91x_dma_deallocate_channel(uint32_t dma_number, uint32_t channel_no)

To deallocate the DMA channel.

sl_status_t
sl_si91x_dma_register_callbacks(uint32_t dma_number, uint32_t channel_no, sl_dma_callback_t *callback_t)

To register the DMA callbacks (transfer complete & error).

sl_status_t
sl_si91x_dma_unregister_callbacks(uint32_t dma_number, uint32_t channel_no, uint8_t callback_type)

To unregister the DMA callbacks (transfer complete & error).

sl_status_t
sl_si91x_dma_transfer(uint32_t dma_number, uint32_t channel_no, sl_dma_xfer_t *dma_transfer_t)

To start the DMA transfer.

sl_status_t
sl_si91x_dma_simple_transfer(uint32_t dma_number, uint32_t channel_no, void *src_addr, void *dst_addr, uint32_t data_size)

To start a simple memory-to-memory DMA transfer.

sl_status_t
sl_si91x_dma_stop_transfer(uint32_t dma_number, uint32_t channel_no)

To stop the DMA transfer.

sl_status_t
sl_si91x_dma_channel_status_get(uint32_t dma_number, uint32_t channel_no)

To get the DMA channel status.

sl_status_t
sl_si91x_dma_channel_enable(uint32_t dma_number, uint32_t channel_no)

To enable the DMA channel.

sl_status_t
sl_si91x_dma_channel_disable(uint32_t dma_number, uint32_t channel_no)

To disable the DMA channel.

sl_status_t
sl_si91x_dma_enable(uint32_t dma_number)

To enable the DMA peripheral.

Macros#

#define

Status code indicates that the DMA channel already allocated for another transfer.

#define

Status code indicates that no DMA channel is available for allocation.

#define

Status code indicates that the DMA channel is already unallocated.

#define

Status code indicates that channel is not allocated for DMA transfer.

#define

DMA channel count.

#define

DMA doesn't use the alternate descriptor.

#define

DMA use alternate descriptor.

#define

DMA burst request enable.

#define

DMA burst request disable.

#define

Channel has low priority.

#define

Channel has high priority.

#define

Peripheral ACK is disabled.

#define

Peripheral Request is disabled.

#define

Peripheral Request is enabled.

#define

DMA request mask disabled.

#define

Next burst enable.

#define

Next burst disable.

#define

Disable source protect control.

#define

Enable source protect control.

Enumeration Documentation#

sl_dma_transfer_type_t#

sl_dma_transfer_type_t

Enumeration to represent DMA transfer types.

This enumeration defines the different types of DMA transfers that can be performed.

Enumerator
SL_DMA_MEMORY_TO_MEMORY

Memory to memory transfer.

SL_DMA_MEMORY_TO_PERIPHERAL

Memory to peripheral transfer.

SL_DMA_PERIPHERAL_TO_MEMORY

Peripheral to memory transfer.


Definition at line 106 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_transfer_mode_t#

sl_dma_transfer_mode_t

Enumeration to represent DMA transfer modes.

This enumeration defines the different transfer modes available for DMA operations.

Enumerator
SL_DMA_BASIC_MODE

Basic DMA mode.

SL_DMA_PINGPONG_MODE

Ping-pong DMA mode.


Definition at line 117 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_peripheral_ack_t#

sl_dma_peripheral_ack_t

Enumeration that holds peripheral ACK signals for DMA.

This enumeration defines the ACK codes for various peripherals that can be used with DMA.

Enumerator
SL_USART0_ACK

ACK code for USART0.

SL_UART1_ACK

ACK code for UART1.

SL_UART3_ACK

ACK code for UART3.

SL_SSI_SLAVE_ACK

ACK code for SSI slave.

SL_SSI_MASTER_ACK

ACK code for SSI master.

SL_SSI1_SLAVE_ACK

ACK code for SSI1 slave.

SL_I2C_ACK

ACK code for I2C.


Definition at line 127 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_transfer_size_t#

sl_dma_transfer_size_t

Enumeration that holds DMA transfer sizes.

This enumeration defines the different transfer sizes available for DMA operations.

Enumerator
SL_TRANSFER_SIZE_32

32-bit (4 bytes) transfer size.

SL_TRANSFER_SIZE_16

16-bit (2 bytes) transfer size.

SL_TRANSFER_SIZE_8

8-bit (1 byte) transfer size.


Definition at line 142 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_transfer_inc_t#

sl_dma_transfer_inc_t

Enumeration that holds DMA transfer address increment options for source and destination.

This enumeration defines the different address increment options available for DMA transfers, specifying how the source and destination addresses should be incremented after each transfer.

Enumerator
SL_TRANSFER_SRC_INC_32

4 bytes source address increment.

SL_TRANSFER_SRC_INC_16

2 bytes source address increment.

SL_TRANSFER_SRC_INC_8

1 byte source address increment.

SL_TRANSFER_SRC_INC_NONE

No source address increment.

SL_TRANSFER_DST_INC_32

4 bytes destination address increment.

SL_TRANSFER_DST_INC_16

2 bytes destination address increment.

SL_TRANSFER_DST_INC_8

1 byte destination address increment.

SL_TRANSFER_DST_INC_NONE

No destination address increment.


Definition at line 154 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_callback_code_t#

sl_dma_callback_code_t

Enumeration that holds 8-bit codes used by the callback_type parameter in the sl_si91x_dma_unregister_callbacks function.

This enumeration defines the 8-bit codes for different types of DMA callbacks that can be unregistered.

Enumerator
SL_DMA_TRANSFER_DONE_CB

8-bit code for transfer complete callback.

SL_DMA_ERROR_CB

8-bit code for error callback.


Definition at line 171 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

Typedef Documentation#

sl_dma_transfer_complete#

typedef void(* sl_dma_transfer_complete) (uint32_t channel, void *data) )(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA transfer completes.

Parameters
[in]channel

DMA channel number.

[in]data

An extra parameter for the user application.

This typedef defines the callback function type that is used by the DMA driver to notify the application when a DMA transfer has completed.


Definition at line 87 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_dma_error#

typedef void(* sl_dma_error) (uint32_t channel, void *data) )(uint32_t channel, void *data)

Typedef for user-supplied callback function which is called when a DMA error occurs.

Parameters
[in]channel

DMA channel number.

[in]data

An extra parameter for the user application.

This typedef defines the callback function type that is used by the DMA driver to notify the application when a DMA error has occurred.


Definition at line 99 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

Variable Documentation#

sl_dma0_channel_allocation_data_t#

sl_channel_data_t sl_dma0_channel_allocation_data_t[SL_DMA0_CHANNEL_COUNT]

DMA0 channel allocation data.

This external variable holds the allocation data for all channels of DMA0, including priority, allocation status, callback functions, transfer type, and transfer mode. DMA0 channel allocator


Definition at line 235 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_ulp_dma_channel_allocation_data_t#

sl_channel_data_t sl_ulp_dma_channel_allocation_data_t[SL_ULP_DMA_CHANNEL_COUNT]

ULP_DMA channel allocation data.

This external variable holds the allocation data for all channels of ULP_DMA, including priority, allocation status, callback functions, transfer type, and transfer mode. ULP_DMA channel allocator


Definition at line 243 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

Function Documentation#

sl_si91x_dma_init#

sl_status_t sl_si91x_dma_init (sl_dma_init_t * dma_init)

To initialize the DMA peripheral.

Parameters
[in]dma_init

Pointer to the DMA initialization structure.

  • dma_init->dma_number: 0 for UDMA0, 1 for ULP_DMA.

This API enables the DMA clock and clears DMA interrupts. Configure dma_init->dma_number to 0 for initializing UDMA0 and 1 for initializing ULP_DMA.

Returns

  • sl_status_t Initialization status:

    • SL_STATUS_OK (0x0000) - Initialization success.

    • SL_STATUS_NOT_INITIALIZED (0x0001) - Initialization failed.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 269 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_deinit#

sl_status_t sl_si91x_dma_deinit (uint32_t dma_number)

To de-initialize the DMA peripheral.

Parameters
[in]dma_number

0 for UDMA0, 1 for ULP_DMA.

This API disables the DMA peripheral clock and interrupts. The DMA will be de-initialized only if there is no ongoing transfer.

Returns

  • sl_status_t De-initialization status:

    • SL_STATUS_OK (0x0000) - De-initialization success.

    • SL_STATUS_BUSY (0x0002) - Cannot de-initialize the peripheral due to an ongoing transfer.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 290 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_allocate_channel#

sl_status_t sl_si91x_dma_allocate_channel (uint32_t dma_number, uint32_t * channel_no, uint32_t priority)

To allocate a DMA channel for the transfer.

Parameters
[in]dma_number

0 for UDMA0, 1 for ULP_DMA.

[in]channel_no

Pointer to the channel number variable:

  • 0: Automatically allocates an available channel for DMA transfer.

  • 1-32: Allocates the given channel for UDMA0 transfer.

  • 1-12: Allocates the given channel for ULP_DMA transfer.

[in]priority

Priority of the channel:

  • 0: Low priority.

  • 1: High priority.

This API checks the available DMA channels and allocates one. It sets the priority of the allocated channel and assigns the channel number to the *channel_no variable. If no channel is available, it will return SL_DMA_NO_CHANNEL_AVAILABLE.

Note: Users can also initialize the desired channel number, and this API checks whether the desired channel is available and allocates the channel if available. If users want the driver to allocate an available channel, channel_no should be initialized to 0.

Returns

  • sl_status_t Channel allocation status:

    • SL_STATUS_OK (0x0000) - Channel allocated.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

    • SL_STATUS_DMA_NO_CHANNEL_AVAILABLE (0x0046) - All DMA channels are allocated.

    • SL_STATUS_DMA_CHANNEL_ALLOCATED (0x0045) - The desired channel is already allocated.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 323 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_deallocate_channel#

sl_status_t sl_si91x_dma_deallocate_channel (uint32_t dma_number, uint32_t channel_no)

To deallocate the DMA channel.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

This API deallocates the DMA channel if there is no ongoing transfer on the channel. Deallocating the channel will also unregister the callbacks for transfer complete and error.

Returns

  • sl_status_t Channel deallocation status:

    • SL_STATUS_OK (0x0000) - Channel deallocated.

    • SL_STATUS_BUSY (0x0002) - Cannot deallocate channel due to an ongoing transfer.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 351 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_register_callbacks#

sl_status_t sl_si91x_dma_register_callbacks (uint32_t dma_number, uint32_t channel_no, sl_dma_callback_t * callback_t)

To register the DMA callbacks (transfer complete & error).

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

[in]callback_t

Pointer to the structure containing callback functions.

This API registers the DMA callbacks for transfer complete and error events. The user must update the sl_dma_callback_t structure and pass its address to this function. A separate callback can be present for transfer complete and error for each channel.

Returns

  • sl_status_t Callback registration status:

    • SL_STATUS_OK (0x0000) - Callback registered successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 380 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_unregister_callbacks#

sl_status_t sl_si91x_dma_unregister_callbacks (uint32_t dma_number, uint32_t channel_no, uint8_t callback_type)

To unregister the DMA callbacks (transfer complete & error).

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

[in]callback_type

Unregister the DMA callbacks based on the callback type (bit-mapped to callbacks):

  • SL_DMA_TRANSFER_DONE_CB: Unregister transfer complete callback.

  • SL_DMA_ERROR_CB: Unregister error callback.

  • SL_DMA_TRANSFER_DONE_CB | SL_DMA_ERROR_CB: Unregister both transfer complete and error callbacks.

This API unregisters the DMA callbacks for transfer complete and error events. Users need to update the 8-bit variable callback_type and pass it to the function. Each bit is mapped to a specific callback.

Returns

  • sl_status_t Callback unregistration status:

    • SL_STATUS_OK (0x0000) - Callback unregistered successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 413 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_transfer#

sl_status_t sl_si91x_dma_transfer (uint32_t dma_number, uint32_t channel_no, sl_dma_xfer_t * dma_transfer_t)

To start the DMA transfer.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

[in]dma_transfer_t

Pointer to the channel transfer data structure containing the channel descriptor and other basic DMA parameters.

This API configures the DMA channel descriptor and initiates the DMA transfer. The DMA primary descriptor is updated in this function, and based on the transfer mode, the alternate descriptor is updated (only for ping pong mode). Other DMA parameters like peripheral ACK signal (for peripheral memory transfers), DMA priority, etc., are also updated in this function.

Returns

  • sl_status_t DMA transfer status:

    • SL_STATUS_OK (0x0000) - Transfer started successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_SUSPENDED (0x0004) - Transfer initialization failed.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 446 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_simple_transfer#

sl_status_t sl_si91x_dma_simple_transfer (uint32_t dma_number, uint32_t channel_no, void * src_addr, void * dst_addr, uint32_t data_size)

To start a simple memory-to-memory DMA transfer.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

[in]src_addr

Source address.

[in]dst_addr

Destination address.

[in]data_size

Transfer size in bytes.

This API configures the DMA channel descriptor and initiates a simple memory-to-memory DMA transfer. Users need to pass the source address and destination address of the transfer along with the transfer length in bytes.

Returns

  • sl_status_t DMA transfer status:

    • SL_STATUS_OK (0x0000) - Transfer success.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_SUSPENDED (0x0004) - Transfer initialization failed.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 479 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_stop_transfer#

sl_status_t sl_si91x_dma_stop_transfer (uint32_t dma_number, uint32_t channel_no)

To stop the DMA transfer.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

This API stops any active transfer on the channel by disabling the DMA channel. If there is no active transfer on the channel, this function returns SL_STATUS_IDLE.

Returns

  • sl_status_t DMA transfer status:

    • SL_STATUS_OK (0x0000) - Transfer stopped successfully.

    • SL_STATUS_IDLE (0x0001) - There is no active transfer on the channel.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Invalid channel number.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 512 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_channel_status_get#

sl_status_t sl_si91x_dma_channel_status_get (uint32_t dma_number, uint32_t channel_no)

To get the DMA channel status.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

This API returns the status of the specified DMA channel. The possible statuses are:

  • SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED - DMA channel allocated but no active transfer in progress.

  • SL_STATUS_BUSY - Channel is allocated and an active transfer is in progress.

  • SL_STATUS_IDLE - Channel is not allocated.

Returns

  • sl_status_t Channel status:

    • SL_STATUS_IDLE (0x0001) - Channel is not allocated.

    • SL_STATUS_BUSY (0x0002) - Channel is allocated and busy.

    • SL_STATUS_DMA_CHANNEL_ALREADY_ALLOCATED (0x0003) - Channel is already allocated and idle.

    • SL_STATUS_NOT_INITIALIZED (0x0004) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 542 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_channel_enable#

sl_status_t sl_si91x_dma_channel_enable (uint32_t dma_number, uint32_t channel_no)

To enable the DMA channel.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

Enabling the channel will trigger the DMA transfer if DMA is already enabled. The channel should be allocated and transfer parameters should be configured before enabling the channel.

Returns

  • sl_status_t Channel enable status:

    • SL_STATUS_OK (0x0000) - Channel enabled successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 570 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_channel_disable#

sl_status_t sl_si91x_dma_channel_disable (uint32_t dma_number, uint32_t channel_no)

To disable the DMA channel.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

[in]channel_no

Channel number:

  • 1-32 for UDMA0.

  • 1-12 for ULP_DMA.

Disabling the DMA channel will abort any ongoing active transfers on the channel. Enabling the channel back will not resume the previous transfer.

Returns

  • sl_status_t Channel disable status:

    • SL_STATUS_OK (0x0000) - Channel disabled successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

    • SL_STATUS_INVALID_PARAMETER (0x000F) - Channel number is invalid.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 596 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

sl_si91x_dma_enable#

sl_status_t sl_si91x_dma_enable (uint32_t dma_number)

To enable the DMA peripheral.

Parameters
[in]dma_number

DMA number:

  • 0 for UDMA0.

  • 1 for ULP_DMA.

Enabling the DMA will trigger the transfer if the channel is already enabled. The channel should be allocated and transfer parameters should be configured before enabling the DMA.

Returns

  • sl_status_t DMA enable status:

    • SL_STATUS_OK (0x0000) - DMA enabled successfully.

    • SL_STATUS_NOT_INITIALIZED (0x0003) - DMA peripheral not initialized.

For more information on status codes, see SL STATUS DOCUMENTATION.


Definition at line 618 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

Macro Definition Documentation#

SL_STATUS_DMA_CHANNEL_ALLOCATED#

#define SL_STATUS_DMA_CHANNEL_ALLOCATED
Value:
  (sl_status_t)0x45

Status code indicates that the DMA channel already allocated for another transfer.


Definition at line 50 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

SL_STATUS_DMA_NO_CHANNEL_AVAILABLE#

#define SL_STATUS_DMA_NO_CHANNEL_AVAILABLE
Value:
  (sl_status_t)0x46

Status code indicates that no DMA channel is available for allocation.


Definition at line 52 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

SL_STATUS_DMA_CHANNEL_ALREADY_UNALLOCATED#

#define SL_STATUS_DMA_CHANNEL_ALREADY_UNALLOCATED
Value:
  (sl_status_t)0X47

Status code indicates that the DMA channel is already unallocated.


Definition at line 54 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

SL_STATUS_DMA_CHANNEL_UNALLOCATED#

#define SL_STATUS_DMA_CHANNEL_UNALLOCATED
Value:
  (sl_status_t)0X48

Status code indicates that channel is not allocated for DMA transfer.


Definition at line 56 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

SL_CHANNEL_COUNT#

#define SL_CHANNEL_COUNT
Value:
32

DMA channel count.


Definition at line 58 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

ALTERNATE_DESCRIPTOR_DISABLE#

#define ALTERNATE_DESCRIPTOR_DISABLE
Value:
0

DMA doesn't use the alternate descriptor.


Definition at line 60 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

ALTERNATE_DESCRIPTOR_ENABLE#

#define ALTERNATE_DESCRIPTOR_ENABLE
Value:
1

DMA use alternate descriptor.


Definition at line 61 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

BURST_REQUEST_ENABLE#

#define BURST_REQUEST_ENABLE
Value:
1

DMA burst request enable.


Definition at line 62 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

BURST_REQUEST_DISABLE#

#define BURST_REQUEST_DISABLE
Value:
0

DMA burst request disable.


Definition at line 63 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

CHANNEL_PRIO_DISABLE#

#define CHANNEL_PRIO_DISABLE
Value:
0

Channel has low priority.


Definition at line 64 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

CHANNEL_PRIO_ENABLE#

#define CHANNEL_PRIO_ENABLE
Value:
1

Channel has high priority.


Definition at line 65 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

PERIPHERAL_ACK_DISABLE#

#define PERIPHERAL_ACK_DISABLE
Value:
0

Peripheral ACK is disabled.


Definition at line 66 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

PERIPHERAL_REQUEST_DISABLE#

#define PERIPHERAL_REQUEST_DISABLE
Value:
0

Peripheral Request is disabled.


Definition at line 67 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

PERIPHERAL_REQUEST_ENABLE#

#define PERIPHERAL_REQUEST_ENABLE
Value:
1

Peripheral Request is enabled.


Definition at line 68 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

REQUEST_MASK_DISABLE#

#define REQUEST_MASK_DISABLE
Value:
0

DMA request mask disabled.


Definition at line 69 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

NEXT_BURST_ENABLE#

#define NEXT_BURST_ENABLE
Value:
1

Next burst enable.


Definition at line 70 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

NEXT_BURST_DISABLE#

#define NEXT_BURST_DISABLE
Value:
0

Next burst disable.


Definition at line 71 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

SOURCE_PROTECT_CONTROL_DISABLE#

#define SOURCE_PROTECT_CONTROL_DISABLE
Value:
0x000

Disable source protect control.


Definition at line 72 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h

DESTINATION_PROTECT_CONTROL_DISABLE#

#define DESTINATION_PROTECT_CONTROL_DISABLE
Value:
0x000

Enable source protect control.


Definition at line 73 of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_dma.h