Personal tools

Difference between revisions of "Real-Time Embedded Systems"

From iis-projects

Jump to: navigation, search
Line 10: Line 10:
 
A real-time computer system must react to stimuli from the controlled object (or  the  operator) within time intervals dictated by its environment. The  instant  at  which  a  result  must  be  produced  is  called  a  '''deadline'''. If  a  result  has  utility even after the deadline  has  passed, the deadline is classified as a '''soft deadline''', otherwise  it  is  a '''firm deadline'''. When missing a firm  deadline  results in a system failure (e.g. airplane sensor and autopilot systems, spacecrafts and planetary rovers), the deadline is called '''hard deadline'''.
 
A real-time computer system must react to stimuli from the controlled object (or  the  operator) within time intervals dictated by its environment. The  instant  at  which  a  result  must  be  produced  is  called  a  '''deadline'''. If  a  result  has  utility even after the deadline  has  passed, the deadline is classified as a '''soft deadline''', otherwise  it  is  a '''firm deadline'''. When missing a firm  deadline  results in a system failure (e.g. airplane sensor and autopilot systems, spacecrafts and planetary rovers), the deadline is called '''hard deadline'''.
  
Hence, in real-time systems guarantees must be given on the finishing of computations before a deadline, which affects the design of hardware (caches, interconnects, peripherals, interrupts, ...) and software stack (operating system, scheduling, compiler guarantees). Key concepts are '''spatial and temporal isolation''' of components.
+
Hence, in real-time systems guarantees must be given on the finishing of computations before a deadline, which affects the design of hardware (processors, caches, interconnects, peripherals, interrupts, ...) and software stack (operating system, scheduling, compiler guarantees). Key concepts are '''spatial and temporal isolation''' of components, and ''' architecture's predictability''' [2].
  
  
 
[1] ''Kopetz H., Real-Time Systems, 1996''
 
[1] ''Kopetz H., Real-Time Systems, 1996''
 +
[2] ''Rochange C., Time-Predictable Architectures''
  
 
==What we offer==
 
==What we offer==

Revision as of 10:31, 7 January 2022

Real-Time Embedded Systems

A real-time computer system is a computer system in which the correctness of the system behavior depends not only on the logical results of the computations, but also on the physical instant at which these results are produced. In fact, a real-time system changes its state as a function of physical time.

It is reasonable to decompose a real-time system into a set of subsystems called clusters e.g., the controlled object (the controlled cluster), the real-time computer system (the computational cluster) and the human operator (the operator cluster).

Rt system.png


A real-time computer system must react to stimuli from the controlled object (or the operator) within time intervals dictated by its environment. The instant at which a result must be produced is called a deadline. If a result has utility even after the deadline has passed, the deadline is classified as a soft deadline, otherwise it is a firm deadline. When missing a firm deadline results in a system failure (e.g. airplane sensor and autopilot systems, spacecrafts and planetary rovers), the deadline is called hard deadline.

Hence, in real-time systems guarantees must be given on the finishing of computations before a deadline, which affects the design of hardware (processors, caches, interconnects, peripherals, interrupts, ...) and software stack (operating system, scheduling, compiler guarantees). Key concepts are spatial and temporal isolation of components, and architecture's predictability [2].


[1] Kopetz H., Real-Time Systems, 1996 [2] Rochange C., Time-Predictable Architectures

What we offer

Our work leverage both hardware and software interfaces:

  • Hardware design - features addition and enhancement: adding new instructions to cores, specializing interconnects, making cores predictable ...
  • Software design: modifying operating systems (Linux kernel, RTOS such as FreeRTOS, ...), drivers, tasks scheduling.

Contact Information

For more information on this work and discussions about projects, please contact Robert Balas (balasr@iis.ee.ethz.ch) or Alessandro Ottaviano (aottaviano@iis.ee.ethz.ch)

Projects

Available Projects

Projects In Progress

Completed Projects