Integrated Modular Avionics for Space Applications : Input / Output Module

The European Space Agency’s (ESA) IMA for Space project (IMA-SP) defines a reference architecture for space on-board software based on the concept of Integrated Modular Avionics (IMA). This novel software architecture leverages upon the success of its aeronautical IMA counterpart, which changed radically the software and hardware role in avionics development. Part of the IMA-SP platform is a generic I/O module that provides input/output services based on network interfaces and other hardware devices. In compliance with the overall objectives of the platform, the I/O component should not only integrate device control into a partitioned environment, but shall also relieve applications from the burden of addressing I/O directly. This dissertation proposes, discusses and compares several possible architectures for the I/O module. The state of the art aeronautical avionic architecture, as well as the current and new space on-board reference platforms are described in detail to potentiate a representative comparison of the possible I/O architectures. It was concluded that the most fit solution foresees the encapsulation of all I/O related tasks in one dedicated system partition.This solution, named I/O Partition, is able to cope with the I/O handling requirements of the IMA-SP platform. However, it is subject to time partitioning and, therefore, introduces a considerable amount of latency in the I/O communication; latency that must be taken into account during application development. In the course of the implementation and testing activities, it was found that the I/O module configuration and analysis is a complex task that will require specific tool and modeling support. On the long term, it is possible to improve the performance of the developed solution through the use of multi-core computer architectures or through the development of partitioning aware I/O devices.