November 17
22
C
omputer
-
on
-m
odules
Standards for embedded modules
with the latest Intel Atom processors
By Harald Maier,
TQ-Systems GmbH
Users are faced with the question of
how they can optimally use the latest
generation of Intel Atom processors.
Which module standard covers
application requirements the best
and helps to exploit the advantages
of these processors? It pays to take a
closer look, especially in the case of
very tough requirements.
n
Originally marketed under the ‘Apollo Lake
-I’ product name, Intel now has three deriva-
tives on the IOTG embedded roadmap: Intel
Atom x7-E3950, Intel Atom x5-E3940 and
Intel Atom x5-E3930. With these devices, the
company is addressing the broader embedded
market as well as industrial applications. An
extended temperature range, high reliabil-
ity, long service life and features that support
tough real-time applications and virtualiza-
tion should be highlighted here.
Those who are less concerned about tempera-
ture range or usage scenarios can also consider
the Celeron N3350 or the Pentium N4200.
These were previously sold under the ‘Apollo
Lake’ code name and do not possess any spe-
cial modifications for tough embedded use.
Instead, they address PC-typical applications,
for which low performance is typically suffi-
cient, but they also have sufficient reserves to
handle short-term peak loads (cf. turbo mode
factor). All five devices are pin-compatible
and are also uniform in terms of their external
interfaces. All of these devices impress with
very good performance-per-watt ratios and
excellent graphic properties with up to three
high-resolution 4K display interfaces. The use
of standard module form factors has become
established in recent years, especially for x86
embedded processors. Key concepts here are
interchangeability, scalability, upgrade capa-
bility, second-source strategy, time-to-market
and future viability. The following module
standards have successfully established them-
selves in the German and international x86
embedded markets: COM Express (Mini,
Compact, Basic), defined by PCI Industrial
Computer Manufacturers Group (PICMG),
COM.0, SMARC, defined by Standardization
Group for Embedded Technologies (SGeT),
SDT.01, and Qseven, defined by SGet, SDT.02.
SMARC and Qseven cover the lower perfor-
mance range of x86 processors, whereas COM
Express is able to cover the full bandwidth
of performance. Which module standard is
best suited for applications with the new Intel
Atom processors depends entirely on the tech-
nical requirements and environmental condi-
tions of the application.
The Qseven form factor was introduced in
2008 for solutions based on the Intel Atom.
Its dimensions are rather compact at 70mm
x 70mm. The majority of interfaces offered by
the new Intel Atom processors can be made
available to the carrier board. Unfortunately,
only two of the three possible display outputs
can be used. One of the three USB 3.0 inter-
faces must also be omitted. Users who wish to
use the MIPI-CSI camera interface are forced
to connect a flat cable directly to the module.
Connection to the carrier board is made via
a 230-pin card edge connector. Gold-plated
contact surfaces are provided on the module,
which are inserted into the plug connector
of the carrier board. This represents a clear
advantage in terms of costs. Some users who
want to use the new Intel Atom processors
for especially rugged applications consider
this type of contacting to be critical in terms
of shock, vibration and risk of contamina-
tion, and they worry about mid-term con-
tacting problems. With regard to sturdiness,
the low PC-board thickness and mechanical
integration continue to be recurring topics
of discussion. The mechanical stresses that
components and solder joints are subjected to
might impair reliability and service life. The
maximum power consumption of Qseven
modules is limited to 12W by the specifica-
tion and the connectors used. Therefore, it
may be necessary to throttle back the maxi-
mum computing and graphic performance.
Unfortunately, the premium processor vari-
ant, the Intel Atom x7-E3950 with 12W TDP
(thermal design power) exceeds the module
performance limits in terms of total power
consumption.
The SMARC, like the Qseven, uses a card edge
connector, so here too there is debate about
issues relating to ruggedness, reliability and
long service life. The dimensions of the short
version are just 82mm x 50mm. This means
that SMARC is the smallest of the form fac-
COM Express Compact module
with the latest Intel Atom ‘Apollo
Lake -I’ processors, 8GB soldered
DDR3L RAM including ECC
support, extended temperature
range and options like conformal
coating and nano-coating
