Seite 6 - Boards & Solution/ECE Magazine July 2013

n ARM processors today almost reach the com-
plexity of x86 processors. Meanwhile, proces-
sors are clocked at over 1 GHz, fast buses such
as, among others, the PCI Express are the rule
and a DDR3 memory is almost always used.
In addition, the processor’s complete control
requires a variety of voltages and a compre-
hensive sequencing of deep technological skills
both in circuit design and in layout.
Most manufacturers still support circuit design
using appropriate reference designs, but the
user has to rely on his own ability during
layout. The reference designs are mostly created
„quick and dirty.“ They certainly work as a
rule, but they leave much to be desired when
it comes to industrial fitness. Nor is the long-
term availability of every component in the
reference design necessarily checked for obso-
lescence. Since the processor isn’t usually the
user’s core competence, relying on a module
right away to get his product to market faster
and safer is obvious.
Since the user relies on someone else’s know-
how, it’s all the more important to select the
right module provider to avoid nasty surprises
later. So when deciding, it pays first of all to
thoroughly question what the proffered module
actually delivers in terms of future development
security. Following introduction of ARM
Cortex™-A9 processors, which penetrated into
the application area of an x86 processor, just
about every module provider, even providers
who only offered x86 modules, now offer
corresponding modules. As is usual in the x86
world, initial standards for ARMmodules have
been introduced in the market. Although the
term „standard“ is used here in a partly very
inflationary way, it awakens hope in the users
that a standard is finally coming now in the
ARM module market. The users’ expectations
for a standard, and standard-module
providers’ reasoning, involves greater supply
security through the compatibility of different
manufacturer’s modules, and thus the corre-
sponding „second source,“ or through their
interchangeability.
The idea is that if the provider fails for whatever
reason, the second source can be switched to
without any problem. Amazingly, for reasons
of cost and time, very few users employ appro-
priate compatibility tests to check actual inter-
changeability. They generally rely on the
providers’ marketing claims instead. Although
that works mostly without any problem in the
x86 world, or with just a few adjustment steps,
you quickly get a rude awakening in the ARM
world. Details will be highlighted in this article.
System scalability is a further argument from
x86-world standards. In the PC world, every-
body knows his PC’s possible upgrade paths
with the next generation of processors, as
long as they fit into the same socket. The
COM Express standard from the embedded
market apparently offers much greater scala-
bility here from ATOM up to i7 processors.
Design freedom with ARM modules
COVER STORY
By Wolfgang Heinz-Fischer, TQ-Group
The ARM module market
continues to gain momentum.
The number of applications in
which an ARM processor is
used is also climbing steadily.
Therefore the decision about
the right module (provider)
is difficult to make. Pure
marketing arguments often
intermingle with technical
facts here.
July 2013 6
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