Arm SDS

Arm SDS is a VS Code extension for capturing, replaying, inspecting, and validating synchronous data streams from embedded systems. It provides a graphical interface for the Synchronous Data Stream (SDS) Framework, which brings reproducible real-world sensor, audio, image, video, and algorithm data into DSP, ML, and Edge AI development. Captured streams can be reviewed, labeled, and exported for offline analysis, DSP development, and ML training and testing.

SDS recordings turn real-world observations into reusable datasets and repeatable test cases. Use them to train or optimize ML models, reproduce a problem, compare algorithm or model versions, and verify a change on target hardware or an FVP simulation model. Arm SDS lets you review SDS data from both environments; its built-in SDSIO-Server connects only to physical targets to record and play back data.

What you can do

• Capture real-world sensor and media data from an embedded target and preserve it as a reusable engineering asset.
• Explore synchronized inputs and algorithm results together to understand system behavior and identify problems.
• Replay the same inputs to reproduce issues and compare algorithms, models, parameters, targets, or software versions.
• Turn recordings into repeatable test cases and datasets for DSP and ML development, validation, regression testing, and CI workflows.

How it works

The SDS Framework manages periodic fixed-size data blocks as well as variable-size or irregularly timed streams. An SDS-enabled application can record sensor, audio, image, and video input streams together with algorithm output. During playback, it feeds previously captured streams into the application while recording new output, enabling repeatable validation and optimization.

The diagram below shows a target connected through USB. A physical target can also connect through a serial port, a TCP/IP socket, or an RTT connection. See the SDS template application for the target-side application structure and instructions for configuring these interfaces.

The Arm SDS VS Code extension provides a user interface for the SDSIO-Server and SDS data file viewers. It uses the following files:

Prerequisites

Recording data from or playing data back to a target requires:

• A physical target running an application that integrates the SDS Framework and an SDSIO Client interface. The application defines the streams to record or play and transfers them through USB, serial, a TCP/IP socket, or an RTT connection exposed as a local socket. The SDS template application provides a starting point for integrating SDS with target hardware and an algorithm.
• An *.sdsio.yml control file that matches the SDSIO interface implemented by the target. It configures the target connection, directories for SDS data and metadata files, and optional playback steps. You can create this file with Create Configuration or open one supplied with an SDS example.

The target application must be running and its configured USB, serial, network, or debug connection must be available before Arm SDS can connect through the SDSIO-Server. Existing SDS recordings can be inspected without a connected target.

Workflow

1. Open the matching *.sdsio.yml control file and connect Arm SDS to the SDS-enabled target.
2. Capture changing real-world sensor, audio, image, or video input streams, optionally together with algorithm output.
3. Inspect and label the recording, then preserve it as a reusable engineering asset.
4. Replay the captured input streams on hardware or an FVP simulation model while recording new algorithm output.
5. Compare results across models, parameter sets, targets, or software versions and add the test to regression or CI.

This workflow makes failures reproducible and provides evidence that an algorithm change fixes the original condition. Making Edge AI development more productive exemplifies the overall development flow for ML applications.

Connect to a target

The SDSIO-Server records and plays SDS data through a physical target connection. It supports USB, serial, and TCP/IP socket interfaces; RTT connections use a local socket exposed by the debug adapter. FVP simulation does not use the SDSIO-Server, but connects through the VSI3 interface using the same *.sdsio.yml control file.

1. Open the SDS view and select Open SDS Configuration to load an existing *.sdsio.yml control file. Use New SDS Configuration only when starting a new configuration.
2. Select Connect SDSIO Monitor. Arm SDS starts the server with the active *.sdsio.yml control file and connects the monitor to it.
3. Use Record, Play, Stop, and the user flags to interact with the target.

Configure an SDS workspace

The *.sdsio.yml control file configures both the extension UI and the data workflow. For a target connection, it selects the SDSIO-Server interface. A new USB target configuration looks like this:

sdsio:
  interface:
    usb:
  workdir: .
  metadir: .
  play:
    - step: Baseline test
      labels:
        - 0
  flag-info:
    - 0: Enable preprocessing
    - 1: Input variant B
    - 2: Record camera input

User interface

Open the SDS view from the VS Code Activity Bar. It combines the active *.sdsio.yml control file, target connection controls, user flags, stream groups, metadata, and SDS recordings.

1. The SDS View Toolbar contains Actions for playback, recording, target connection, configuration-file access, and other commands.
2. Tree View item inline actions provide frequently used commands for a specific SDS stream or file, such as editing its metadata or opening it in the SDS Viewer.
3. The Tree View item context menu provides all commands available for the selected item, including validation, metadata editing, viewing, CSV export, and deletion.

Commands

The View Actions and item menus provide commands for target control, configuration management, and SDS files. You can also open the VS Code Command Palette and type SDS to find commands that apply without a selected Tree View item.

View SDS data

Open an .sds file from the SDS View. Its *.sds.yml metadata defines how the stream is decoded and displayed. The SDS Viewer shows values and charts, while the Media Viewer handles audio, image, and video. Related viewers synchronize by timestamp so you can correlate algorithm input and output streams.

User flags

User flags are application-defined bits in the target's sdsFlags value. Arm SDS can set or clear these bits through the SDSIO-Server monitor interface; the target application decides what each bit does. A single firmware image can therefore select algorithm options, run A/B tests, or inject test conditions without rebuilding the application.

The flag-info: section of the *.sdsio.yml control file assigns meaningful labels to the flags displayed by Arm SDS. These labels are for the user interface and do not define the target behavior. Playback steps can also set or clear flags to apply the required application state before replaying a stream. See User flags in the SDSIO documentation for the related flag-info:, setflags:, and clearflags: properties.

You can rename a flag in the SDS View; the label is saved in the active *.sdsio.yml control file.

Settings

Configure Arm SDS under Extensions > Arm SDS in the VS Code Settings editor, which describes each option and its default value. The SDSIO monitor-port setting is machine-scoped; when using a remote extension host, change it in Remote Settings. Changes apply on the next connection.

Troubleshooting

The SDSIO-Server does not connect

• Make sure an *.sdsio.yml control file is active and its interface matches the target firmware and connection.
• Confirm that the target application is running and its USB, Ethernet, or RTT connection is available.
• Open View > Output, select Arm SDS, and review the executable, *.sdsio.yml control file, monitor port, and errors.
• Disconnect before changing the *.sdsio.yml control file or connection interface, then connect again.

The preferred monitor port is unavailable

The local monitor uses TCP port 6060 by default. Before starting SDSIO, the extension checks the preferred port. If it is occupied or access is denied, the operating system selects an available port, which is passed to both server and client. The selected port appears in the Arm SDS output channel; the setting itself is not changed.

This check cannot detect firewall filtering, and another process could claim the port before server startup. If problems persist, allow the SDSIO-Server through the local firewall or choose another cmsis-sds.sdsio.monitorPort in VS Code User or Remote Settings.

Recordings or metadata do not appear

• Check that workdir and metadir are valid paths relative to the active *.sdsio.yml control file.
• Refresh the SDS View after files are created outside VS Code.
• Check that metadata uses the stream-group base name and ends in .sds.yml or .sds.yaml.

A viewer cannot decode a file

• Verify the data type, sample rate, block layout, and media properties in the associated metadata.
• Use Check Data File to verify the recording.
• Use Open SDS Viewer for sensor data and Open Media Viewer for audio, image, or video data.

Check Data File cannot find SDS Check

SDS Check is bundled in the extension's tools directory (sds-check.exe on Windows, sds-check on Linux/macOS). It does not require an installed SDS software pack, CMSIS_PACK_ROOT, or a separate Python installation. If the executable is missing, reinstall the extension for your platform. When running from source, download the bundled SDS tools as described in CONTRIBUTING.md.

Links

• Arm SDS pack overview
• SDS Framework documentation
• SDS template application
• SDS data-file format
• SDS YAML metadata format
• *.sdsio.yml control file
• SDS examples
• Report an Arm SDS extension issue