Posts Tagged ‘assembly’

11 August, 2014

I have always liked writing. From an early age, I had an ambition to write a book. My first attempt, in my mid-teens, was a science fiction novel. It was not a success. I wrote about 100 pages and I may even still have the typescript. I remember being embarrassed last time I looked at it. One of the best days of my life was back in 1986, when a jiffy bag arrived in the mail containing a book with my name on the cover.

Since then, I have never really stopped writing … Read the rest of this entry »

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14 July, 2014

As I have talked about before, I am particularly interested in programming languages, with a strong focus on embedded, of course. So, I always take a look when I see a survey that looks at what developers are using and what the trends are. When I saw that the IEEE were publishing some results, they really had my attention.

However, all was not what it seems … Read the rest of this entry »

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16 December, 2013

Nowadays, social networking is becoming quite “grown up” and goes a long way beyond teens discussing how to (mis)spend their time or posting 200 near identical and blurred photographs of last night’s awesome [sic] party. Although I do use Facebook, in a professional context I think that LinkedIn has much more value. Although it is essentially “Facebook for adults”, there is true potential for building a strong professional network, if you work in company or industry with global reach.

I particularly like some of the LinkedIn groups and I have recently been participating in a discussion about embedded C programmingRead the rest of this entry »

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18 February, 2013

I am very interested in the pros and cons of various programming languages for embedded applications. Although I mostly favor C, I sometimes prefer C++, but I am open to suggestions. I started out writing assembly language and still feel that this is the “real thing”. This is a topic I posted about some time ago. I expanded my thoughts in a more recent article on embedded.com

I am always pleased when one of my colleagues offers to write a guest blog, as I think that different views can be interesting. Brooks Moses [who has kindly contributed a number of times before, like here] has some very interesting views and experience to share … Read the rest of this entry »

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17 December, 2012

Yesterday evening we had dinner with friends. The guy works on real time control systems and was talking about the trouble he is having with some young, well qualified engineers, who think that they know everything, even though they have very little experience of the real world. Our wives exchanged glances – they knew that he and I were on common ground, but a place outside of their world. He continued: “But they do not really understand the whole point behind writing code”. As this is a subject close to my heart, that I have written about before, I explained my view on the matter. He said “Exactly.” And, to the relief of our better halves, we moved on to other topics.

The subject of why code is written was stuck in my brain … Read the rest of this entry »

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18 July, 2011

I have always been interested in programming languages. The first one I used, way back when I was at university, was FORTRAN [4, not 77]. I then moved on to do a bit of assembly, BCPL, a few flavors of Algol, Simula 67, SNOBOL 4 – just about everything that was around at the time, except COBOL. Later, in the course of my career as a software engineer, I came back to FORTRAN and assembly, then Forth, RTL/2, Pascal, C, C++ and a bit of Java. Of course, at various times, some kind of BASIC must have featured in my portfolio.

I have often mused upon which language is best for embedded. With the possible exception of assembly, there is no ideal language, as they have all been designed for other purposes. The best bet seems to be C, which, if used carefully, gives the right balance between capability/flexibility and productivity. C++ has fair potential too, but has had a lot of bad press. So, I was interested to see publication of the latest research on the topic by VDCRead the rest of this entry »

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21 March, 2011

A constant challenge I have found, when teaching or mentoring people, is to avoid making assumptions about what they know. I have found that it is so easy to assume that, because something is obvious to me, it is clearly apparent to everyone else. On numerous occasions I have discovered that this not to be the case. Of course, the best response to this realization is not to treat everyone else as stupid, but try to explain something clearly and then listen to the echo back of the explanation.

In developing software – embedded software in particular – there are certain things that are fundamental, particularly around the conservation of resources. More than once I have been surprised by engineers’ inability to focus on this issue … Read the rest of this entry »

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7 March, 2011

Last week I attended the Embedded World show in Nuremberg, Germany. I have been to this event most years and it just seems to get bigger and bigger. I have not seen the latest detailed statistics, but they claim to be the largest embedded exhibition in the world and I think that there is every reason to believe this claim is valid. The event is well organized and the location makes a lot of sense.

I did not have the opportunity to spend a lot of time wandering the show floor, so I am not going to even try to give an impression of what was on offer. In any case, there are numerous online news sources where you can read comprehensive reports. For me, the interesting experience was the conference … Read the rest of this entry »

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29 June, 2009

There is a paradox with programming languages. Everyone would agree that standardizing languages is a good thing, leading to portability of software and programming skills. But what if the resulting standard lacks features required by certain types of applications? One possible approach is to define a language specification that is so large that it encompasses every possible eventuality. In the late 1960s, IBM created the “ultimate” programming language, which had capabilities that accommodated numerous types of applications – it was called PL/1. Although it was widely used [on IBM mainframes] for some years, it had a fundamental problem: because the language was so large, each programmer would tend to learn and use just a sub-set of the available facilities, so they would not necessarily be able to understand one another’s code. This rather defeats the point of a standard. Another approach is to keep the specification quite lean, but complete enough for most applications and accept that language extensions may be necessary for specific specialized needs.

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8 June, 2009

If, like many embedded software developers, you need to work “close to the hardware”, you will want to be able to visualize the bit patterns that map on to CPU and peripheral registers. The obvious way to do this is in binary, as you can see the 1s and 0s directly. However, I do not think that I have ever seen the option, even in assembly language, to include binary constants in software. Do feel free to comment or email me if you know of examples.

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27 May, 2009

It would seem intuitive that writing in assembly language is the best possible option if you want the most optimal code in terms of size and/or speed. After all, assuming the programmer is smart and competent in the assembler for a particular CPU and understands its architecture well enough, and he has been fully appraised of the functional requirements of the code, the only possible result is code that uses the processor’s capabilities in an ideal way. A compiler just cannot compete, as it has no information on the precise requirements of the code.

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@colin_walls tweets

  • My latest video blog is now available. I talk about the use of a memory management unit [MMU] in an embedded system https://t.co/aSVECLARgl
  • Embedded software article: RTOS Revealed #6 look at the additional facilities that and RTOS may offer & beyond https://t.co/GXg8ivM3gW
  • #programmingTip To maintain real time integrity, keep ISRs as short as possible - unload the real work onto a task.

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