One example of an ARM-based SoC is Texas Instruments’
OMAP3. It combines a Cortex A8 ARM processor with separate
TI DSPs for audio and video as well as dedicated processors to
handle graphics and security. The memory interface supports
package-on-package construction, squeezing the full processor
and memory subsystem into 12- by 12-mm board area. Nvidia’s
Tegra is another offering from the ARM camp. The single chip
combines an ARM 11 CPU core with graphics, imaging, and
video coprocessors, I/O peripherals, and a security engine.
Freescale Semiconductor also takes the SoC approach with its
MobileGT 5121e design, but the company seeks to cover a broader
market than just Internet access devices. The MobileGT family
includes several industrial bus interfaces along with the peripheral
interfaces common to most computing systems (Fig. 4).
This allows the processor be at home in industrial, consumer,
and other embedded system designs, helping ensure stability in
the architecture and availability by decoupling the processor’s fate
from the PC device market’s “all-or-nothing” demand characteristics.
It also positions the processor to serve the needs of specialty
Internet access devices that target business applications, such as
inventory control, rather than personal consumer connectivity.
INTEL’S MULTI-PRONG APPROACH
Intel takes a three-pronged approach to this marketplace, creating
variations of its Atom core architecture that address different
design tradeoffs. According to Pankaj Kedia, director of Atom’s
ecosystem program, “one size does not fit all.” Intel has created
Atom families that offer various levels of integration, performance,
and power demands to fit different use models. These
Atom families, Kedia noted, aren’t just cut-down PC processors,
but were designed specifically for the Internet access market.
The Atom 230 series targets what Intel calls the “nettop” computer,
portable but intended for desktop operation. This gives
the design access to line power, supporting the 1.6-GHz clocks
and the 4-W demand of 230-series processors and their support
chip set. In exchange for the higher power, these processors add
the 64-bit operation, virtualization, and multitasking features of
a notebook PC. They aren’t intended to power low-end PCs,
though. Rather, they run fixed-function Internet connectivity and
office productivity devices. The Atom 230 series thus targets one
extreme of the MID landscape.
Intel homes in on the other design extreme with its Z500 series,
code-named Silverthorne. These devices integrate the support
chipset to reduce a design’s processing core size to a 22- by 22-mm
package. They step down the clock frequency to 800 MHz to
help reduce power demands to under 220 mW average. The
Z-series also integrates a graphics processor to handle 780p
encoding and 1080p decoding, offloading the core CPU to help
control power consumption.
For the vast middle ground of MID use cases, Intel offers the
Atom N270 series. Like the 230 series, the processor utilizes a
separate support chip to bridge to memory and system peripherals,
but the processor does not incorporate quite as many performance
features as the 230.
However, it does incorporate a graphics processor on-chip. As a
result, an Internet access device design based on the N270 would
require about 2.5 W to power the design’s core processing functions.
This leaves the N270 more suited to the netbook end of the
middle ground.
COMPATIBILITY QUESTIONS REMAIN
All of the processors in the Atom families retain their PC heritage
by offering x86 compatibility. Like the Via Nano, the Atom
processors thus seek to avoid any possible incompatibility in their
Web browsing operation.
Via’s Browne points out that browser plug-ins for Internet content
such as Flash programs and some streaming media primarily
target the x86 architecture and may not perform well or even be
available for other processor architectures.
Freescale’s Bryars disagrees, however, noting that “Flash and
other plug-ins are de facto standards that change every day and
all processor architectures continually need new versions.” At best,
Bryars adds, x86 compatibility gives developers only a short-term
advantage due to the funding and market penetration currently
enjoyed by the architecture.
Freescale and other non-PC processor vendors are banking
on the fact that the Internet-centric operation of devices in this
emerging market will eliminate any requirement for PC compatibility,
leaving the market up for grabs.
Several such designs have already emerged, including the Freescale-
based CherryPal and LimePC (Fig. 5). New entries based
on various processors are appearing with greater frequency, the
latest carrying the Google brand.
While the first entries have arrived, the opportunity still remains
for developers to join in. Users will need time to become accustomed
to the new interfaces and use models that sidestep their
familiar PC environment, but when they do they will be primed to
adopt whatever design best fits their needs.
Because we are all different, those needs vary, creating a host of
potential market niches. And once started, the battle for users of
Internet access devices will undoubtedly spill into other, currently
unforeseen, market opportunities.