DSPs operate in either fixed-point arithmetic or floating point arithmetic. In general, most of the high performance DSPs operate with fixed-point arithmetic because of different reasons that have to do with number of arithmetic instructions that can be executed per second (in many cases by parallelizing over several ALUs, power dissipation, memory use and access bandwidth, etc.). Because of this, a basic but important skill for anybody working with DSPs is to know how fixed-point arithmetic works.

One of the tricky points found at the beginning of working with fixed point arithmetic is that, although the DSP architecture determines the number of bits of the registers used for arithmetic operations, the placement of the decimal point within those bits is entirely up to the programmer’s choice. Even more, the programmer can change the placement of the decimal point from one operation to the next with no problem as long as it keeps track of where the decimal point is.

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It has been a very long time since my last post, let’s just say that the time demands of modern life have not been very kind to me lately… In any case, good news is that the Holidays are giving me that extra time to catch up with this blog.

Some weeks ago I intended to write about an interesting technology to store information that is heavily based on DSP technologies. The idea behind the technology is quite interesting and a nice example of outside-the-box thinking. In a nutshell, the idea is to store information on a piece of paper by using color coding. More interestingly, since I read the first article about this, there have been more discussions about the validity and practicality of this idea.

From my point of view, the discussion is itself interesting because it brings up a lot of issues related to several DSP technologies. From the creative standpoint, I believe that although there are many challenges with this technology in its current form, who knows where it can end and where the related DSP problems may take us to? I guess, it’s about the journey, not the destination.