Computer Science

Share this article:

Computer Science

  • Join our comunity:

Software Instrumentation

By: , Posted on: May 15, 2017

Embedded software development tools are important to all developers and a topic that I frequently discuss. The way such tools are described by vendors is interesting. For example, there might be a reference to an “optimizing compiler”. That is rather meaningless, as all compilers are optimizing to at least some degree. For an embedded compiler, the important factors are the quality of optimization and, more importantly, the degree of control that the user can apply.

Another interesting terminological issue is applied to debuggers and trace tools. They are commonly referred to as “non-intrusive” …

Most people will have heard of Heisenberg’s Uncertainty Principle. Although it has a precise meaning in the realm of quantum physics (which is well beyond the scope of this blog!), it does highlight a basic rule of life: you cannot measure something without affecting the thing that you are trying to measure; i.e. the act of measurement affects the result. This applies in a surprisingly diverse range of circumstances and has useful side benefits.

If you are an electronics designer, you may need to measure a voltage in a circuit. That measurement drains a (very tiny) current, which affects the voltage. If you measure a current, a resistance is introduced, which affects the current. To look at timings and waveforms, an oscilloscope is the standard tool. The application of the ‘scope probes, affects the capacitance of the circuit, which, in turn, may modify the timing behavior. Does all this matter? Normally, no, because the effects are so tiny that they may be ignored. Sometimes, however, the effect (of tiny timing changes) may cause the circuit to malfunction. Such a fault can be hard to track down, but it does indicate that the design is rather marginal and some work to make it more robust would be advisable.

Surprisingly, the rule applies to software as well. A debugger may use a hardware probe, which has a small effect upon the timing of the code. There may be a debug agent to facilitate “run mode” debug or extra operating system instrumentation to enable profiling. Both of these affect the size of the code and, more importantly, its real time behavior. Just like with the hardware design, the effects are likely to be tiny. However, any problems that do arise simply serve to highlight poor (i.e. fragile) design.

On a future occasion maybe I will look at more parallels from nuclear physics, which teach useful principles. Maybe we can discuss the half life of executing software …

Read more from Colin about embedded software on SciTech Connect

Colin’s most recent publication, Embedded Software: The Works is available now on the Elsevier Store. Embedded Software The Works new cover

Save 30% on his book and other Newnes Press and embedded systems books. Use discount code “STC317″ at checkout. 

About the Author

Colin WallsColin Walls (@Colin_Walls) is an embedded software technologist at Mentor Graphics (@mentor_graphics), the leading EDA software company.

You can read more about Colin and his work on embedded systems at The Colin Walls Blog at Mentor Graphics here. Connect with Colin online here:

facebook google plus linkedin slideshare twitter wordpress

Connect with us on social media and stay up to date on new articles

Computer Science

Computing functionality is ubiquitous. Today this logic is built into almost any machine you can think of, from home electronics and appliances to motor vehicles, and it governs the infrastructures we depend on daily — telecommunication, public utilities, transportation. Maintaining it all and driving it forward are professionals and researchers in computer science, across disciplines including:

  • Computer Architecture and Computer Organization and Design
  • Data Management, Big Data, Data Warehousing, Data Mining, and Business Intelligence (BI)
  • Human Computer Interaction (HCI), User Experience (UX), User Interface (UI), Interaction Design and Usability
  • Artificial intelligence (AI)
Morgan Kaufmann companion resources can be found here You can also access companion materials and instructor’s resources for all our new books on the Elsevier Store. Search by author, title or ISBN, then look for the “Resources” tab on any book page. Looking for companion materials or instructor’s resources for these titles? Connect below: