The Internet of Things encompasses literally anything, from wearables to automobiles and everything in between. While form factors, connectivity, functionality — and myriad other factors — may differ from one “thing” to another, every connected device must have a processor. However, even processors can vary widely, and companies have to make a number of decisions when selecting one.
“The processor is the heart of a semiconductor,” says Bill Ray, Gartner senior research director. “It does the mathematics. It runs the program.” As an example, Ray said a sensor in a thermostat may collect temperature data, but that data can’t go directly to a communications chip. “The processor takes the data and packages it and sends it to the communications chip. If the data hasn’t changed, the processor may determine that there’s no need to send it again,” he says.
An IoT processor is not to be confused with a system on a chip, which “contains a radio chip, memory, processor and connectivity all bundled up into one piece of silicon,” Ray says. “Currently, with the IoT, we see a lot of variation in processors.”
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That is due to the diversity of connected devices. “Today, there’s a chip in everything. Those new frontiers have different workloads than a server in a data center, or a desktop, or a cellphone. You have constraints on size, memory and performance demands as well as lower energy consumption. The level of innovation is going through the roof because there’s so many different places to stick a chip, and the barriers to entry are going down,” says Calista Redmond, chief executive officer, RISC-V.
Most companies are experimenting with IoT solutions. According to Ray, they don’t know what connectivity technology to use, whether they need to have GPS functionality, how many sensors they need, etc. “We see separate processes deployed,” Ray says. “They’re produced in small quantities and used in small-scale deployments. When companies work out which apps will be popular, then they will start making custom chips for those apps, and those will be SoCs.”
Selecting an IoT Processor
When choosing a processor, the main factor to consider is how much processing power you need, which is dictated by the software you want to run. “You have to write software for the sensor. If you go to 32-bit, you can use Linux and hire loads of cheap programmers. It’s easy and quick to develop for,” Ray says. “If you go with 16-bit, you have to hire someone who knows a low-level programming language, and that will cost more. In the long term, it will also cost more to maintain the software.”
The software has an impact on power consumption, and that must be considered as well. “The more processing power available, the more complex OS you will write, and more functionality you have. That will increase power consumption, which can be an issue depending on the application,” Ray warns.