README.md

# XMC™ MCU: DMA ring buffer

This code example demonstrates how to receive data using DMA via a universal serial interface channel (USIC) and synchronize the processing with an OS task through a ring buffer.

[View this README on GitHub.](https://github.com/Infineon/mtb-example-xmc-dma-ring-buffer)

[Provide feedback on this code example.](https://cypress.co1.qualtrics.com/jfe/form/SV_1NTns53sK2yiljn?Q_EED=eyJVbmlxdWUgRG9jIElkIjoiQ0UyMzI1NzIiLCJTcGVjIE51bWJlciI6IjAwMi0zMjU3MiIsIkRvYyBUaXRsZSI6IlhNQyZ0cmFkZTsgTUNVOiBETUEgcmluZyBidWZmZXIiLCJyaWQiOiJzdWJyYW1hbml5YXAiLCJEb2MgdmVyc2lvbiI6IjIuMi4wIiwiRG9jIExhbmd1YWdlIjoiRW5nbGlzaCIsIkRvYyBEaXZpc2lvbiI6Ik1DRCIsIkRvYyBCVSI6IklDVyIsIkRvYyBGYW1pbHkiOiJOL0EifQ==)


## Requirements

- [ModusToolbox™](https://www.infineon.com/modustoolbox) v3.1 or later (tested with v3.1)
- [SEGGER J-Link software](https://www.segger.com/downloads/jlink/#J-LinkSoftwareAndDocumentationPack)
- Programming Language: C
- Associated parts: All [XMC4000 MCU](https://www.infineon.com/cms/en/product/microcontroller/32-bit-industrial-microcontroller-based-on-arm-cortex-m/32-bit-xmc4000-industrial-microcontroller-arm-cortex-m4/) parts


## Supported toolchains (make variable 'TOOLCHAIN')

- GNU Arm® Embedded Compiler v11.3.1 (`GCC_ARM`) – Default value of `TOOLCHAIN`

## Supported kits (make variable 'TARGET')

- [XMC4200 Platform2GO Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc_plt2go_xmc4200/) (`KIT_XMC_PLT2GO_XMC4200`)
- [XMC4300 Relax EtherCAT Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc43_relax_ecat_v1/) (`KIT_XMC43_RELAX_ECAT_V1`) – Default value of `TARGET`
- [XMC4400 Platform2GO Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc_plt2go_xmc4400/) (`KIT_XMC_PLT2GO_XMC4400`)
- [XMC4500 Relax Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc45_relax_v1/) (`KIT_XMC45_RELAX_V1`)
- [XMC4700 Relax Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc47_relax_v1/) (`KIT_XMC47_RELAX_V1`)
- [XMC4800 Relax EtherCAT Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc48_relax_ecat_v1/) (`KIT_XMC48_RELAX_ECAT_V1`)

## Hardware setup

This example uses the board's default configuration. See the kit user guide to ensure that the board is configured correctly.

Additionally, an USB-to-UART serial adapter is required to test the code example on the [XMC4500 Relax Kit](https://www.infineon.com/cms/en/product/evaluation-boards/kit_xmc45_relax_v1/).


## Software setup

See the [ModusToolbox™ tools package installation guide](https://www.infineon.com/ModusToolboxInstallguide) for information about installing and configuring the tools package.

Install a terminal emulator if you don't have one. Instructions in this document use [Tera Term](https://teratermproject.github.io/index-en.html).

This example requires no additional software or tools.

## Using the code example

### Create the project

The ModusToolbox™ tools package provides the Project Creator as both a GUI tool and a command line tool.

<details><summary><b>Use Project Creator GUI</b></summary>

1. Open the Project Creator GUI tool.

   There are several ways to do this, including launching it from the dashboard or from inside the Eclipse IDE. For more details, see the [Project Creator user guide](https://www.infineon.com/ModusToolboxProjectCreator) (locally available at *{ModusToolbox&trade; install directory}/tools_{version}/project-creator/docs/project-creator.pdf*).

2. On the **Choose Board Support Package (BSP)** page, select a kit supported by this code example. See [Supported kits](#supported-kits-make-variable-target).

   > **Note:** To use this code example for a kit not listed here, you may need to update the source files. If the kit does not have the required resources, the application may not work.

3. On the **Select Application** page:

   a. Select the **Applications(s) Root Path** and the **Target IDE**.

   > **Note:** Depending on how you open the Project Creator tool, these fields may be pre-selected for you.

   b.	Select this code example from the list by enabling its check box.

   > **Note:** You can narrow the list of displayed examples by typing in the filter box.

   c. (Optional) Change the suggested **New Application Name** and **New BSP Name**.

   d. Click **Create** to complete the application creation process.

</details>

<details><summary><b>Use Project Creator CLI</b></summary>

The 'project-creator-cli' tool can be used to create applications from a CLI terminal or from within batch files or shell scripts. This tool is available in the *{ModusToolbox&trade; install directory}/tools_{version}/project-creator/* directory.

Use a CLI terminal to invoke the 'project-creator-cli' tool. On Windows, use the command-line 'modus-shell' program provided in the ModusToolbox&trade; installation instead of a standard Windows command-line application. This shell provides access to all ModusToolbox&trade; tools. You can access it by typing "modus-shell" in the search box in the Windows menu. In Linux and macOS, you can use any terminal application.

The following example clones the "[mtb-example-xmc-dma-ring-buffer](https://github.com/Infineon/mtb-example-xmc-dma-ring-buffer)" application with the desired name "Dma_Ring_Buffer" configured for the *KIT_XMC43_RELAX_ECAT_V1* BSP into the specified working directory, *C:/mtb_projects*:

   ```
   project-creator-cli --board-id KIT_XMC43_RELAX_ECAT_V1 --app-id mtb-example-xmc-dma-ring-buffer --user-app-name Dma_Ring_Buffer --target-dir "C:/mtb_projects"
   ```


The 'project-creator-cli' tool has the following arguments:

Argument | Description | Required/optional
---------|-------------|-----------
`--board-id` | Defined in the <id> field of the [BSP](https://github.com/Infineon?q=bsp-manifest&type=&language=&sort=) manifest | Required
`--app-id`   | Defined in the <id> field of the [CE](https://github.com/Infineon?q=ce-manifest&type=&language=&sort=) manifest | Required
`--target-dir`| Specify the directory in which the application is to be created if you prefer not to use the default current working directory | Optional
`--user-app-name`| Specify the name of the application if you prefer to have a name other than the example's default name | Optional

<br>

> **Note:** The project-creator-cli tool uses the `git clone` and `make getlibs` commands to fetch the repository and import the required libraries. For details, see the "Project creator tools" section of the [ModusToolbox&trade; tools package user guide](https://www.infineon.com/ModusToolboxUserGuide) (locally available at {ModusToolbox&trade; install directory}/docs_{version}/mtb_user_guide.pdf).

</details>



### Open the project

After the project has been created, you can open it in your preferred development environment.


<details><summary><b>Eclipse IDE</b></summary>

If you opened the Project Creator tool from the included Eclipse IDE, the project will open in Eclipse automatically.

For more details, see the [Eclipse IDE for ModusToolbox&trade; user guide](https://www.infineon.com/MTBEclipseIDEUserGuide) (locally available at *{ModusToolbox&trade; install directory}/docs_{version}/mt_ide_user_guide.pdf*).

</details>


<details><summary><b>Visual Studio (VS) Code</b></summary>

Launch VS Code manually, and then open the generated *{project-name}.code-workspace* file located in the project directory.

For more details, see the [Visual Studio Code for ModusToolbox&trade; user guide](https://www.infineon.com/MTBVSCodeUserGuide) (locally available at *{ModusToolbox&trade; install directory}/docs_{version}/mt_vscode_user_guide.pdf*).

</details>


<details><summary><b>Keil µVision</b></summary>

Double-click the generated *{project-name}.cprj* file to launch the Keil µVision IDE.

For more details, see the [Keil µVision for ModusToolbox&trade; user guide](https://www.infineon.com/MTBuVisionUserGuide) (locally available at *{ModusToolbox&trade; install directory}/docs_{version}/mt_uvision_user_guide.pdf*).

</details>


<details><summary><b>IAR Embedded Workbench</b></summary>

Open IAR Embedded Workbench manually, and create a new project. Then select the generated *{project-name}.ipcf* file located in the project directory.

For more details, see the [IAR Embedded Workbench for ModusToolbox&trade; user guide](https://www.infineon.com/MTBIARUserGuide) (locally available at *{ModusToolbox&trade; install directory}/docs_{version}/mt_iar_user_guide.pdf*).

</details>


<details><summary><b>Command line</b></summary>

If you prefer to use the CLI, open the appropriate terminal, and navigate to the project directory. On Windows, use the command-line 'modus-shell' program; on Linux and macOS, you can use any terminal application. From there, you can run various `make` commands.

For more details, see the [ModusToolbox&trade; tools package user guide](https://www.infineon.com/ModusToolboxUserGuide) (locally available at *{ModusToolbox&trade; install directory}/docs_{version}/mtb_user_guide.pdf*).

</details>



## Operation


1. Connect the board to your PC using a Micro-USB cable through the debug USB connector.

2. Open a terminal program and select the **JLink CDC UART COM** port. Configure the terminal with a baud rate of 115200, data bits of 8, stop bit of 1, and with parity and flow control set to none.

3. Program the board using one of the following:

   <details><summary><b>Using Eclipse IDE</b></summary>

      1. Select the application project in the Project Explorer.

      2. In the **Quick Panel**, scroll down, and click **\<Application Name> Program (JLink)**.
   </details>


   <details><summary><b>In other IDEs</b></summary>

   Follow the instructions in your preferred IDE.
   </details>


   <details><summary><b>Using CLI</b></summary>

     From the terminal, execute the `make program` command to build and program the application using the default toolchain to the default target. The default toolchain is specified in the application's Makefile but you can override this value manually:
      ```
      make program TOOLCHAIN=<toolchain>
      ```

      Example:
      ```
      make program TOOLCHAIN=GCC_ARM
      ```
   </details>

4. After programming, the application starts automatically. Confirm that the "DMA Ring Buffer example" is displayed on the UART terminal.

   **Figure 1. DMA ring buffer example in terminal**

   ![](images/terminal-dma-ringbuffer-example.png)

5. Type inside the terminal.

6. Confirm that the text you type is echoed on the terminal.


## Debugging


You can debug the example to step through the code.


<details><summary><b>In Eclipse IDE</b></summary>
Use the **\<Application Name> Debug (JLink)** configuration in the **Quick Panel**. For details, see the "Program and debug" section in the [Eclipse IDE for ModusToolbox&trade; user guide](https://www.infineon.com/MTBEclipseIDEUserGuide).

</details>


<details><summary><b>In other IDEs</b></summary>

Follow the instructions in your preferred IDE.

</details>


## Design and implementation

The code consists of two parts as follows:

- **Part 1:** Defines and configures the DMA channel. The source address configured in the DMA is the 'RBUF' register (XMC_UART0_CH0->RBUF), where the data should be read from. The destination address is the address of the first element in the ring buffer array `ring_buffer[0]`. The data received via the UART and saved in the ring buffer is echoed to the UART. This task takes over the `SysTick_Handler()` interrupt function, which calls the `uart_transmit()` function to transmit the data from the ring buffer when new data is written by the DMA to the ring buffer.

- **Part 2:** Initializes and enables the DMA module in the main function using the configuration from the earlier step. It also configures the system time using the `SysTick_Config()` function, which calls the `SysTick_Handler()` function every 1 ms.


### Resources and settings

The project uses a custom *design.modus* file because the following settings are modified in the default *design.modus* file.

**Figure 2. USIC channel**

![](images/usic0_uart_inst.png)

<br>

## Related resources

Resources | Links
----------------|----------------------
Code examples | [Using ModusToolbox&trade;](https://github.com/Infineon/Code-Examples-for-ModusToolbox-Software) on GitHub
Device documentation | [XMC4000 family datasheets](https://www.infineon.com/cms/en/product/microcontroller/32-bit-industrial-microcontroller-based-on-arm-cortex-m/32-bit-xmc4000-industrial-microcontroller-arm-cortex-m4/#document-group-myInfineon-49) <br> [XMC4000 family technical reference manuals](https://www.infineon.com/cms/en/product/microcontroller/32-bit-industrial-microcontroller-based-on-arm-cortex-m/32-bit-xmc4000-industrial-microcontroller-arm-cortex-m4/#document-group-myInfineon-44)
Development kits |[XMC&trade; MCU eval boards](https://www.infineon.com/cms/en/product/microcontroller/32-bit-industrial-microcontroller-based-on-arm-cortex-m/#boards)
Libraries on GitHub | [mtb-xmclib-cat3](https://github.com/Infineon/mtb-xmclib-cat3) – XMC&trade; MCU peripheral library (XMCLib)
Tools  | [ModusToolbox&trade;](https://www.infineon.com/modustoolbox) – ModusToolbox&trade; software is a collection of easy-to-use libraries and tools enabling rapid development with Infineon MCUs for applications ranging from wireless and cloud-connected systems, edge AI/ML, embedded sense and control, to wired USB connectivity using PSoC&trade; Industrial/IoT MCUs, AIROC&trade; Wi-Fi and Bluetooth&reg; connectivity devices, XMC&trade; Industrial MCUs, and EZ-USB&trade;/EZ-PD&trade; wired connectivity controllers. ModusToolbox&trade; incorporates a comprehensive set of BSPs, HAL, libraries, configuration tools, and provides support for industry-standard IDEs to fast-track your embedded application development.

<br>


## Other resources

Infineon provides a wealth of data at [www.infineon.com](https://www.infineon.com) to help you select the right device, and quickly and effectively integrate it into your design.

For XMC&trade; MCU devices, see [32-bit XMC&trade; industrial microcontroller based on Arm&reg; Cortex&reg;-M](https://www.infineon.com/cms/en/product/microcontroller/32-bit-industrial-microcontroller-based-on-arm-cortex-m/).

## Document history

Document title: *CE232572* – *XMC&trade; MCU: DMA ring buffer*

 Version | Description of change
 ------- | ---------------------------
 1.0.0   | New code example
 1.0.1   | Updated README
 1.1.0   | Added support for more kits
 2.0.0   | Updated to support ModusToolbox&trade; v3.0. This CE is not backward compatible with previous versions of ModusToolbox&trade;
 2.1.0   | Added support for DMA personality
 2.1.1   | Updated README
 2.2.0   | Updated to support ModusToolbox&trade; v3.1
<br>

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© 2024 Infineon Technologies AG

All Rights Reserved.

### Legal disclaimer

The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party.

### Information

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