Spacewire Interface Simulation

Abstract

Spacewire [1] is an interface standard for high rate peer-to-peer intercommunication between several nodes and routers for example between payloads and a spacecraft on-board computer. The functionalities of Spacewire continue to increase, mainly due to the increase of on-board software complexity. New facilities have to be provided to support the development and testing of Spacewire and on-board software applications. This paper provides an overview of a generic “request - action list” concept for real-time interface simulation physically implemented as a Spacewire Interface Simulator (SWIS). The SWIS concept provides a means of generic peer-to-peer interface simulations of the packet, protocol and application layer with free user- defined functionality for several simultaneous Spacewire links. A payload simulation can be established by “drag and drop” in a much shorter time than usually needed for project specific software development. Using the SWIS test and system engineers as well as managers can prepare simulations without any need for real-time software development. The effort (i.e. cost and time) for development of the test facility is reduced and the quality may increase significantly.