Software architecture in embedded development outlines the design, organization, and interaction of software components. This article will give you a brief intro to software architecture in embedded systems.

Source: ST Microcontroller

The Problem with No Clear Architecture: Spaghetti Code and Nightmares

Developing software for an embedded system without a defined architecture can feel like wrangling a tangle of wires. Without a clear structure, code can become a mess of interconnected functions, making it difficult to understand, modify, or fix problems. This can lead to a tangled mess of code, also known as the “spaghetti code.” This “spaghetti code” leads to nightmarish debugging and headaches in maintenance. Such code is barely reusable or scalable.

Key Factors in Designing Effective Software Architecture for Embedded Systems

In the context of embedded systems, software architecture must accommodate the constraints and requirements of the hardware and real-time operating environments. Embedded software architecture typically caters to:

• Modular Design: Breaking down the system into manageable modules or components.
• Interaction Patterns: Defining how components communicate and interact.
• Resource Management: Ensuring efficient use of limited resources like memory, processing power, and energy.
• Real-time Requirements: Meeting timing constraints critical for the system’s functionality.

Why is Software Architecture in Embedded Systems Necessary?

• Maintainability: A well-defined architecture makes it easier to update and maintain the software.
• Scalability: Modular design allows for easier scalability of the system.
• Reliability: Clear architecture improves system reliability and reduces bugs.
• Efficient Resource Utilization: Optimized use of limited resources leads to better performance.
• Facilitates Compliance: Developing a standard compliant system requires you to follow defined development standards. These standards are only met if you have a clear software architecture. A few examples of such standards include:
  • ISO 26262: For automotive functional safety.
  • IEC 62304: For medical device software lifecycle processes.
  • DO-178C: For airborne systems and equipment software.

Tools that Help in Software Architecture Design

You can make use of various tools and technologies for designing embedded software architecture.

• Design and modeling tools like Enterprise Architect, IBM Rational Rhapsody, and MATLAB/Simulink aid in UML modeling and system simulation.
• Simulation tools such as QEMU and Proteus validate architectural changes.
• Static analysis tools, including PC-lint and Coverity, identify bugs and compliance issues. Through such analysis you can identify areas of improvements in your architecture.
• Software stacks like RTOS (FreeRTOS, VxWorks, QNX), middleware (AUTOSAR, OPC UA) and hardware abstraction layers (CMSIS, Arduino HAL) streamline development and standardization.

Conclusion

A well-structured software architecture forms the foundation of effective embedded software development.  A robust architecture facilitates maintainability, scalability, adaptability, and compliance with industry standards. It ensures that the system performs its intended functions efficiently and reliably. Skipping the important step of defining the architecture introduces technical debt and makes debugging, maintenance, and scaling of the software difficult.