SoCs: look beyond the norm for more choices

By Don Dingee Editorial Director

Industrial System-on-Chip (SoC) solutions have simply exploded in numbers during the past several years. Widely available intellectual property, improved mixed-signal designs, and advanced fabrication technologies have combined, allowing devices to proliferate in a seemingly endless number of variants.

Let’s suppose a design team has to go out and research the problem of selecting an SoC. Conventional thinking segments microcontrollers by the normal parameters of word size and instruction set architecture. With some research, designers will find massive tables comparing devices by these parameters.

If a particular architecture is already in use at a company, congratulations – this narrows the selection considerably. Simply research devices within the preferred architecture – ARM, PIC, Power, MIPS, MSP430, AVR32, SuperH, 8051, ColdFire, or one of many others – and select a device with the right feature mix for the application.

But I think allowing designers to choose a device that best fits the problem and explore advantages offered by various architectures is a much more interesting opportunity. Plenty of noteworthy devices are out there, some with proven longevity and some that emerged recently.

The categories of 8-, 16-, and 32-bit have blurred a lot, so I decided to take a different approach to SoC selection with an abstract look at examples sorted by architecture in three general categories. Please note my lists certainly aren’t exhaustive, and many vendors offer devices in several architectures spanning different performance and feature ranges. Also note I’m not covering an entire range of FPGAs with embedded processor cores that could be considered in this space. You can learn more about those platforms in our sister publication, DSP-FPGA.com.

Spartan
Designers limited by real estate and power consumption are looking for a Spartan device – simple, austere, and frugal. These devices listed in Table 1 usually have few if any extras, but are instead designed to do a particular job very efficiently. Several vendors still offer 4-bit machines, but most of the action starts at 8-bit architectures and moves up from there. I also discovered that several parts come in some type of Dual Inline Packaging (DIP), which is not that small but easy for prototyping.

Table 1

Well-balanced
If you have a bit more to work with, devices that provide more performance and integrated features show up here in Table 2. Size and power consumption aren’t unlimited and yet don’t overly constrain designs. Scalability is usually possible with support for external memory and peripherals. Some of these SoCs even offer a level of configurability.

Table 2

Brawny
Many applications are asking for even bigger and badder engines – computational intensity, multimedia capability, and networking performance beyond the midrange. When designers ask for more and more performance and features, SoC vendors respond with sophisticated, fast, and highly integrated devices, often with multiple cores. These devices listed in Table 3 are packing a punch never seen before in industrial applications.

Out of the ordinary
These examples show just some of the exciting things going on in the industrial SoC space. It is evident that the market is offering many more options beyond the plain vanilla microcontroller with limited peripheral options expected just a few years ago.