If you are British or are an aficionado of British TV, you will be familiar with the TV series ‘Doctor Who’. If you’re both, and like me, of a certain age, you may recall a childhood of watching this show from behind the sofa. It’s the longest running science-fiction TV show in the world and it’s scary. One of the key props in the story is the Tardis, a time-machine disguised as an old-fashioned Police Telephone Box. (It’s a long story why it’s a rather incongruous Police Box.) The Tardis allows the good Doctor to travel back & forwards in time. As I look at the Embedded Software industry today, I was thinking, what if I accompanied the Doctor back to ten years ago. How did the industry look compared to now? How would it look ten years into the future?
VLIW (Very Long Instruction Word) machines first appeared in the early 1980’s. They were used primarily as scientific super computers. At the time with semiconductors still in their infancy and process geometries measured in microns it made sense to bolt two (or more) execution units together and tolerate the software and real-time inefficiencies that this creates. There were few better options at the time if you wanted to increase performance. Pushing the problem off to the compiler made sense because there were fundamental limitations on the number of transistors that you could put on a chip and by extension the level of functionality that could be implemented.