Aimed at industrial applications, this system-on-module helps simplify design of powerful IoT systems running mainline Linux

By Richard Quinnell, editor-in-chief

are many microcontrollers and associated modules vying to become the basis of
Internet of Things (IoT) designs, but many industrial applications need the
performance that only a full-fledged microprocessor can provide. Such processors
need operating systems to run their feature-rich applications code. Now
Microchip is making the design of such powerful IoT systems easier with a new
system-on-module (SoM) that clears the path for bringing mainline Linux to the

the designer’s point of view, there are considerable differences between using
a microcontroller (MCU) and a microprocessor (MPU) as a product’s foundation.
Because microcontrollers lack integral system and program memory as well as
peripherals, for instance, these vital resources must appear on the PCB as
separate components. Their presence, in turn, greatly complicates development as
designers are forced to deal with signal integrity and routing issues for
high-speed connections to things like DDR memory and gigabit Ethernet physical
layers (PHY). For industrial applications, in which long product life is
essential, using peripheral and memory devices that must be drawn from an
ever-evolving consumer market complicates component sourcing as well.

development can be equally challenging. MPU-based designs typically require the
use of an operating system (OS) to facilitate the creation and maintenance of
application code. But finding developers experienced with proprietary code can
be challenging. Having the ability to use an industrialized version of the
ubiquitous Linux would be an advantage.

its introduction of the ATSAMA5D27
SoM, Microchip is addressing all of these issues. The SoM is based on the SAMA5D2
system-in-package (SiP), which integrates a Cortex-A5 processor with up to 1 Gb
of DDR2 memory to eliminate the need for manual impedance matching. The module
combines the SiP with Flash memory, boot EEPROM, Ethernet PHY, and power
management chips onto a PCB to further reduce the designer’s task. The module
has soldering pads located on the edge, allowing developers to simply drop the
SoM onto a four-layer PCB and have all of the difficult design issues resolved.


SoM also resolves sourcing issues. Microchip fabricates most of the parts used
and has long-term supply agreements for the remainder. Industrial developers
need not worry about end-of-life issues on memory or other key chips during
their design’s production life. This also helps insulate manufacturers from the
major pricing fluctuations chat characterize the DRAM market.

software, the SoM supports mainline Linux so that development teams can draw
from an extensive talent pool. Furthermore, this version of Linux is intended for
long-life applications and will be actively maintained for up to six years.

onboard interfaces for LCD displays, a Bayer camera, capacitive touch, and an
audio subsystem, Microchip’s SoM, in many ways, exhibits characteristics similar
to those of experimental and hobbyist-oriented modules. But there are critical
differences. The Microchip modules will be available worldwide and in full-production volumes to support commercial usage and can be customized to meet
unique needs. Furthermore, they meet payment card industry (PCI) security standards
with features such as secure boot, memory integrity checker, and on-the-fly
encrypted communications between the MCU and system memory.

The SoM is available now for $39 in 100-unit
quantities, and the SiP on which the module is based is available starting at
$8.62 each in 10,000-unit quantities. There is also a development board available
for $249.