We've had application-specific integrated circuits (ASICs) and systems-on-a-chip (SoCs) in this industry for a long time. But what each of those actually is has changed over the years, due to time, technology, and trends. Like so many other things, ASIC and SoC became "buzzwords," which meant just about whatever you wanted them to mean to fit your storyline.
How so? Very often, the ASIC was somewhat "application-specific," but it was often also usable in a fairly broad range of associated applications. As for the SoC, it seemed to be more a case of definition and frame of reference than actual use, since one person's "system" is another person's "component." Note that for a circuit designer, a component is an IC, a resistor, capacitor, diode, etc.; for the audio-studio designer, it's a rack-mounted chassis. So we go from one end of the spectrum to the other.
If I may muddy the waters even further, the acronymns "ASIC" and "SoC" have often been used by digital designers to describe design methodologies that are largely independent of a target "application" or one's concept of a "system."
By that I mean that some of us have, for years, used what we referred to as an "ASIC methodology," which simply meant that digital logic was synthesized from RTL to standard library cells and then automatically placed & routed -- i.e., few or no custom cells of our own creation and little or no manual intervention in physical design.
An "SoC methodology" was essentially a type of ASIC methodology, but included one or more large IP cores -- typically microprocessors -- that might be integrated as hard cells or might be synthesized & placed & routed using an IP provider's RTL, scripts and guidance.
The concept of an analog ASIC or analog SoC of course doesn't fit either of my methodology descriptions, although some of today's very complex AMS designs might.
Like I said, just muddying the waters with further abuse of those overly-used acronyms!
Join our online Radio Show on Friday 11th July starting at 2:00pm Eastern, when EETimes editor of all things fun and interesting, Max Maxfield, and embedded systems expert, Jack Ganssle, will debate as to just what is, and is not, and embedded system.