This page gives an overview of thebare-metal driver support for theXilinx® LogiCORE™ IP AXI Central Direct Memory Access (CDMA) soft IP.
The AXI CMDA core is a soft Xilinx IP core for use with the Xilinx Vivado® Design Suite. The AXI CDMA provides high-bandwidth Direct Memory Access (DMA) between a memory-mapped source address and a memory-mapped destination address using the AXI4 protocol. An optional Scatter Gather (SG) feature can be used to offload control and sequencing tasks from the system CPU. Initialization, status, and control registers are accessed through an AXI4-Lite slave interface.For more information, please refer to the AXI CDMA product pagewhich includes links to the official documentation and resource utilization.
The source code for the driver is included with the Vitis Unified Software Platform installation, as well as being available in the Xilinx Github repository.
| Driver Name | Path in Vitis | Path in Github |
|---|---|---|
| axicdma | <Vitis Install Directory>/data/embedded/XilinxProcessorIPLib/drivers/axicdma_<version> | https://github.com/Xilinx/embeddedsw/tree/master/XilinxProcessorIPLib/drivers/axicdma |
Note: To view the sources for a particular release, use the rel-version tag in github. For example, for the 2020.1 release, the proper version of the code is:https://github.com/Xilinx/embeddedsw/tree/xilinx-v2020.1/XilinxProcessorIPLib/drivers/axicdma
The driver source code is organized into different folders. The table below shows the axicdma driver source organization.
| Directory | Description |
|---|---|
| doc | Provides the API and data structure details |
| data | Driver .tcl, .mdd file and .yaml files |
| examples | Example applications that show how to use the driver features |
| src | Driver source files, make and cmake files |
Note: AMD Xilinx embeddedsw build flow is changed from 2023.2 release to adapt to the new system device tree based flow. For further information, refer to the wiki pagePorting embeddedsw components to system device tree (SDT) based flow - Xilinx Wiki - Confluence (atlassian.net).
The .yaml(in data folder) andCMakeLists.txt(in src folder) files are needed for the System Device Tree based flow. The Driver .tcl and .mdd files are for the older build flow which will be deprecated in the future.
For a full list of features supported by this IP, please refer to theAXI CDMA product page.
Features
The AXI CDMA Standalone driver supports the following features:
- Supports Simple DMA mode
- Supports Scatter/Gather Direct Memory Access (DMA)
- Supports 64-bit Addressing
- Supports Optional Data Re-Alignment Feature
- Supports Register Direct mode
Known Issues and Limitations
- All IP features are supported
For simple/SG mode the examples assumes AXI CDMA Data AXI4 Read/Write MasterIP M_AXI/M_AXI_SG interface are connected to DDR.
Example Applications
Refer to the driver examples directory for various example applications that exercise the different features of the driver. Each application is linked in the table below. The following sections describe the usage and expected output of the various applications. These example applications can be imported into the Vitis IDE from the Board Support Package settings tab.
Links to Examples
Examples Path:https://github.com/Xilinx/embeddedsw/tree/master/XilinxProcessorIPLib/drivers/axicdma/examples
| Test Name | Example Source | Description |
|---|---|---|
| Scatter Gather DMA with Interrupts | xaxicdma_example_sg_intr.c | This example demonstrates how to transfer packets in interrupt modewhen the core is configured in SG Mode. |
| Scatter Gather DMA with Polling | xaxicdma_example_sg_poll.c | This example demonstrates how to transfer packets in the polled mode when the core is configured in SG Mode. |
| Simple DMA with Interrupt | xaxicdma_example_simple_intr.c | This example demonstrates how to transfer packets in interrupt mode when the core is configured in simple DMA Mode. |
| Simple DMA with Polling | xaxicdma_example_simple_poll.c | This example demonstrates how to transfer packets in the polled mode when the core is configured in simple DMA Mode. |
| Hybrid(SG+ simple) with Interrupts | xaxicdma_example_hybrid_intr.c | This example demonstrates how to transfer packets in interrupt mode when the core is configured in hybrid(SG + simple) transfer Mode. |
| Hybrid(SG+ simple) with Polling | xaxicdma_example_hybrid_poll.c | This example demonstrates how to transfer packets in the polled mode when the core is configured in hybrid(SG + simple) transfer Mode. |
Example Application Usage
Scatter Gather with Interrupts
This example demonstrates how to transfer packets in interrupt modewhen the core is configured in SG Mode.
Expected Output
--- Entering main() ---Successfully ran XAxiCdma_SgIntr Example--- Exiting main() ---
Scatter Gather with Polling
This example demonstrates how to transfer packets in the polled mode when the core is configured in SG Mode.
Expected Output
--- Entering main() ---Successfully ran XAxiCdma_SgPoll Example--- Exiting main() ---
Simple DMA with Interrupts
This example demonstrates how to transfer packets in interrupt mode when the core is configured in simple DMA Mode.
Expected Output
--- Entering main() ---Successfully ran XAxiCdma_SimpleIntr Example--- Exiting main() ---
Simple DMA with Polling
This example demonstrates how to transfer packets in the polled mode when the core is configured in simple DMA Mode.
Expected Output
--- Entering main() ---Successfully ran AxiCdma_SimplePoll Example--- Exiting main() ---
Hybrid(SG+ simple) with Interrupts
This example demonstrates how to transfer packets in interrupt mode when the core is configured in hybrid(SG + simple) transfer Mode.
Expected Output
--- Entering main() ---First simple transfer successfulScatter gather transfer successfulSecond simple transfer successfulSuccessfully ran Axicdma Hybrid interrupt Example--- Exiting main()
Hybrid(SG+ simple) with Polling
This example demonstrates how to transfer packets in the polled mode when the core is configured in hybrid(SG + simple) transfer Mode.
Expected Output
--- Entering main() ---First simple transfer successfulScatter gather transfer successfulSecond simple transfer successfulSuccessfully ran Axicdma Hybrid polled Example--- Exiting main()
2023.2
https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2023.2/doc/ChangeLog#L540
2023.1
https://github.com/Xilinx/embeddedsw/blob/xilinx_v2023.1/doc/ChangeLog#L50
2022.2
https://github.com/Xilinx/embeddedsw/blob/xilinx_v2022.2/doc/ChangeLog#L72
2022.1
None
2021.2
None
2021.1
https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2021.1/doc/ChangeLog#L396
Related Links
- http://www.wiki.xilinx.com/Baremetal+Drivers+and+Libraries
