Over the past several years, Apple (NASDAQ:AAPL) has become a semiconductor powerhouse. The company's A-series processors found inside its iPhone and iPad are generally regarded as best-in-class, and I believe that the company's efforts here are just getting started.

In fact, to get a better handle on the future of Apple's processors, I regularly peruse job postings at Apple. Here I would like to present what is perhaps my most interesting finding yet, as I think it pretty clearly spells out the future of Apple's processors.

Understanding a mobile system-on-a-chip
A mobile processor is a complex thing that integrates a number of different sub-processors that all perform different functions. Apple's A-series processors, for example, integrate general purpose CPU cores, graphics processors, image signal processors, multimedia engines, and a whole lot more to support the functionality of the iPhone and the iPad.

In other words, the "brains" of the system more or less reside on those A-series processors.

Now, over time, mobile devices will be called upon to do even more sophisticated and performance-intensive tasks. Many of these tasks, such as more lifelike 3-D games and more advanced productivity functions, will be enabled by the natural evolution of the CPU and graphics cores found on a mobile chip today.

Apple, however, thinks that future iPhones and iPads will have such sophisticated functionality that simply advancing the current blocks inside a mobile system-on-a-chip won't be enough.

Remember what Phil Schiller said about facial detection?
At the iPhone 6 launch, Apple's Phil Schiller pointed out that Apple had built dedicated hardware into its A8 processor to perform facial detection. Note that prior iPhones were able to perform this facial detection, but it's likely that the processing to do so ran on the general-purpose CPU cores rather than on a dedicated processor.

As I said in the article I linked to in the previous paragraph, dedicated hardware designed to perform a limited range of well-defined tasks is generally more efficient than running those tasks on general-purpose hardware. The downside is that specialized hardware requires more effort to build and takes up chip space.

That said, as transistor geometries continue to shrink, chip designers will have plenty of space to add new functionality. It seems that Apple believes that further going down the specialized-hardware road is the right way to go.

Apple will be developing a "complete range" of specialized processors
With that background in mind, take a look at the following Apple job description for an "SoC Processor RTL Design Engineer":

Source: Apple.

Notice the first bullet point: Apple is looking to develop a "complete range of application specific signal processors." Further, also note that this team is "newly formed," meaning that the dedicated facial recognition hardware found on the A8 is just the tip of the iceberg.

What this means, in a nutshell, is that Apple is planning on introducing some pretty interesting new usage models into its latest iPhone and iPad products that haven't even been discussed yet. These usage models are probably so sophisticated, and so important, that Apple is willing to pay expensive chip engineers to build custom hardware for those particular usage models.

Finally, it's worth pointing out that since Apple will be developing these custom blocks in-house, it doesn't need to reveal to any third parties what functionality it plans to bake into its chips. If Apple were buying chips from a third party, the third party would probably incorporate that functionality into its chips, making it available for all buyers of those chips. This way, if Apple has insight into new functionality that requires a specialized processor, it can keep that insight and the hardware implementation all to itself.