Most common real-time embedded programming languages provide a means to specify functionality; however, they have few constructs to specify precise timing constraints. LabVIEW is one example of a graphical programming language that supports timing specifications in the form of timed-loops. In this work, we present a plug-in for LabVIEW Embedded that maps the LabVIEW G graphical programming language and its timing specifications to the PREcision Timed machine (PRET), an architecture that exposes timing instructions in its instruction set architecture. We demonstrate the use of the plug-in with a simple producer/consumer example that uses timing to enforce synchronization.

 

 

An Automated Mapping of Timed Functional Specification to A Precision Timed Architecture(paper)

Projects

Publications

Shanna-Shaye Forbes, Hugo A. Andrade, Hiren Patel, Edward A. Lee. An Automated Mapping of Timed Functional Specification to A Precision Timed Architecture, Proceedings of the 12-th IEEE International Symposium on Distributed Simulation and Real Time Applications, October, 2008.

Shanna-Shaye Forbes, Jia Zou, Slobodan Matic, Edward A. Lee, Poster Abstract: “PtidyOS: An Operating System based on the PTIDES Programming Model” 15th IEEE Real-Time and Embedded Technology and Applications Symposium, April, 2009.

PtidyOS: An Operating System for the PTIDES Programming Model

On time execution of events is critical to correct functionality in hard real-time embedded systems. We look at Programming Temporally Integrated Distributed Embedded Systems (PTIDES) [1], a programming model for such systems. PTIDES extends the discrete-event model of computation, by bounding time stamps of events at specific ports in the system to physical time. PTIDES leverages this fact to allow better processor utilization in processing events.

PtidyOS is a lightweight operating system aimed at distributed real-time embedded systems. By implementing timed semantics as defined in PTIDES, PtidyOS is novel compared to conventional real-time operating systems because it enables deterministic execution of programs with real-time constraints. It uses a single-stacked scheme to process events and presents the general microkernel services of an embedded operating system. Finally, PtidyOS leverages traditional scheduling schemes such as earliest-deadline-first that is optimal with respect to scheduling feasibility.

[1] Patricia Derler, Thomas Huining Feng, Edward A. Lee, Slobodan Matic,Hiren D. Patel, Yang Zhao, Jia Zou. Ptides: A programming model for distributed real-time embedded systems. Technical Report UCB/EECS-2008-72, University of California, Berkeley, 2008.