University of Dundee DOCTOR OF PHILOSOPHY Deterministic SpaceWire Networks Gibson, David James Award date: 2017 Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 24. Sep. 2021 Deterministic SpaceWire Networks David James Gibson Doctor of Philosophy University of Dundee October 2017 ii Table of Contents List of Figures ......................................................................................................... xiii List of Tables............................................................................................................ xix List of Acronyms ..................................................................................................... xxi Glossary .................................................................................................................. xxv Acknowledgements ............................................................................................... xxvii Declaration of the Candidate ............................................................................... xxviii Declaration of the Supervisor................................................................................. xxix Abstract ................................................................................................................... xxx Introduction ................................................................................................................. 1 1.1 Research Questions ...................................................................................... 2 1.2 Outcomes ..................................................................................................... 2 1.3 Thesis Structure ............................................................................................ 4 Background ................................................................................................................. 5 2.1 Spacecraft Subsystems ................................................................................. 5 2.1.1 Attitude and Orbit Control ..................................................................... 5 2.1.2 Communications .................................................................................... 6 2.1.3 On-Board Computers ............................................................................. 7 2.1.4 Scientific Instruments............................................................................. 7 2.2 SpaceWire .................................................................................................... 8 iii 2.2.1 Development History ............................................................................. 9 2.2.2 Protocol Stack ........................................................................................ 9 2.2.2.1 Physical Level ............................................................................... 10 2.2.2.2 Signal Level .................................................................................. 10 2.2.2.3 Character Level ............................................................................. 11 2.2.2.4 Exchange Level............................................................................. 12 2.2.2.5 Packet Level .................................................................................. 15 2.2.2.6 Network Level .............................................................................. 15 2.3 SpaceWire-D .............................................................................................. 17 2.3.1 Motivation ............................................................................................ 17 2.3.2 Operation .............................................................................................. 18 2.3.2.1 Time-Slots ..................................................................................... 18 2.3.2.2 Virtual Buses................................................................................. 19 2.3.2.3 Schedules ...................................................................................... 28 2.4 Missions ..................................................................................................... 29 2.4.1 Magnetospheric Multiscale Mission .................................................... 29 2.4.2 ASTRO-H ............................................................................................ 32 2.4.3 JUpiter ICy moons Explorer ................................................................ 34 2.5 Other Communication Networks ............................................................... 36 2.5.1 MIL-STD-1553 .................................................................................... 36 2.5.1.1 Node Types ................................................................................... 36 iv 2.5.1.2 Transfer Types .............................................................................. 37 2.5.1.3 ECSS Standardisation ................................................................... 39 2.5.2 Controller Area Network...................................................................... 42 2.5.2.1 Message Identifiers ....................................................................... 42 2.5.2.2 Arbitration ..................................................................................... 42 2.5.2.3 Transfer Types .............................................................................. 44 2.5.3 Other Networks .................................................................................... 46 2.5.4 Comparison .......................................................................................... 47 2.5.4.1 Time-Division Multiplexing ......................................................... 47 2.5.4.2 Exclusive or Non-Conflicting Access to Network ....................... 48 2.5.4.3 Data Rates and Protocol Overhead ............................................... 49 2.5.4.4 Acknowledgements ....................................................................... 51 2.5.4.5 Multiple Initiators ......................................................................... 51 2.5.4.6 Fault Detection, Isolation and Recovery....................................... 52 2.5.4.7 Comparison Summary .................................................................. 53 2.6 On-Board Data Systems ............................................................................. 55 2.7 Summary .................................................................................................... 57 Research Questions ................................................................................................... 60 3.1 Research Questions .................................................................................... 60 3.1.1 Designing a SpaceWire-D Software Layer .......................................... 61 3.1.2 Designing a SpaceWire-D Demonstrator ............................................. 61 v 3.1.3 Scheduling SpaceWire-D Networks .................................................... 62 3.1.4 Summary .............................................................................................. 63 SpaceWire-D Software Layer ................................................................................... 64 4.1 Overview .................................................................................................... 65 4.2 RTEMS Board Support Package ................................................................ 66 4.2.1 RTEMS in Space .................................................................................. 67 4.2.2 Porting Process ..................................................................................... 68 4.2.2.1 Existing LEON Support ................................................................ 68 4.2.2.2 Cross-Compiling Toolchain .......................................................... 69 4.2.2.3 Loading and Debugging................................................................ 69 4.2.3 Creating the BSP .................................................................................. 70 4.2.3.1 Configuration Files ....................................................................... 70 4.2.3.2 Linker Command Script................................................................ 71 4.2.3.3 Board Initialisation ....................................................................... 73 4.2.3.4 Interrupt Vectoring ....................................................................... 74 4.2.3.5 Example: Ticker ............................................................................ 77 4.3 SpaceWire-D Layer .................................................................................... 79 4.3.1 Architecture .........................................................................................