Subject: Embedded System

Difficulty: Medium

Marks: 4 marks

Key specifications of RTOS:-

1. Reliability: A reliable system must be available (continue to provide service) and should not fail. The combination of all system elements determines the reliability of a system. ( Hardware, BSP, RTOS, and applications)

2. Predictability: The RTOS used in this case needs to be predictable to a certain degree. The term deterministic describes RTOSes with predictable behavior, in which the completion of operating system calls occurs within known timeframes.

3. Performance: An embedded system must perform fast enough to fulfill its timing requirements. Typically, the processor's performance is expressed in million instructions per second (MIPS). Throughput also measures the overall performance of a system, with hardware and software combined. One definition of throughput is the rate at which a system can generate output based on the inputs coming in.

4. Compactness: In embedded systems, where hardware real estate is limited due to size and costs, the RTOS clearly must be small and efficient. In these cases, the RTOS memory footprint can be an important factor.

5. Scalability: Because RTOSes can be used in a wide variety of embedded systems, they must be able to scale up or down to meet application-specific requirements. Depending on how much functionality is required, an RTOS should be capable of adding or deleting modular components, including file systems and protocol stacks.