By Majeed Ahmad, contributing editor

What’s
next in the FPGA technology realm? If the flurry of design announcements in
technology media tells you anything, it’s that the time for the embedded FPGA
or eFPGA has finally come. Achronix Semiconductor calls 2017 the breakout
growth year for the eFPGA technology.

The
San Jose, California-based chip firm claims that that’s when its revenue grew
700% year-over-year and that its headcount increased by 30% in 2017. Other
semiconductor outfits pushing the eFPGA initiative include Flex Logix, Menta,
and QuickLogic.

The
FPGA lite technology is promising to combine the ASIC design efficiency with
FPGA’s flexibility for incorporating hardware accelerators on a single chip.
And that allows engineers to change the configuration or firmware of the chip
later on to meet the changing needs of the design.

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This is how an eFPGA (right) differs
from a conventional FPGA. Image Credit: Flex Logix.

The
ecosystem around the eFPGA technology is quickly evolving as firms like
QuickLogic start offering evaluation boards for testing their eFPGA IP products.
Likewise, Achronix offers the rigorous bench and ATE verification of its
Speedcore IP built into chips manufactured on the TSMC 16-nm FinFET+ process
node.

QuickLogic
has also released the Aurora software for the evaluation of its ArticPro eFPGA
IP designed into GlobalFoundries process nodes. Both GlobalFoundries and TSMC
have vowed to incorporate the eFPGA technology into their design toolsets.

What’s an eFPGA?
It
allows system-on-chip (SoC) designers to embed the FPGA core without
incorporating typical FPGA components such as GPIO, SerDes, and PHY. And that
eliminates the need for I/O used to connect FPGA to the host device. Moreover,
it allows SoCs to be customized after production without expensive and
time-consuming redesign efforts.

In
other words, chip designers can keep the hard-wired portion of their ASIC
intact while updating the FPGA portion whenever needed. Timothy Saxe, CTO of
QuickLogic, says that it can save nearly 40% in development costs. Other
benefits of adopting the eFPGA approach include smaller die size, lower power
consumption, and as mentioned above, post-production design flexibility.

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A view of custom blocks of Achronix’s
Speedcore eFPGA IP.

The
FPGA densities range from less than 10,000 look-up tables (LUTs) to up to 2 million
LUTs plus large amounts of embedded memory and DSP blocks. What an eFPGA device
does here is allow SoC designers to define custom functions that can be added
as additional blocks in the eFPGA fabric.

That,
in turn, enables chip designers to create reprogrammable hardware accelerators
in order to address changing standards and thus future-proof their designs. The
SoC developers can specify their logic, memory, and DSP resource needs and then
configure the eFPGA IP according to their particular needs. Next, the LUTs, RAM
blocks, and DSP resources can be assembled like building blocks to create the
optimal programmable fabric for a specific application.

eFPGA applications
The
eFPGA solutions are penetrating the hardware accelerator market for offloading
CPU data processing tasks in the data center, 5G wireless, and other
high-performance computing applications. Here, the eFPGA-based hardware
accelerators significantly expand the range of compute tasks for machine
learning, artificial intelligence, and software-defined networks.

The
eFPGAs can also be used in sensor fusion tasks to run sensor hub operations at low
power budgets, allowing the main CPU to focus on data-processing operations. That’s
why developers are targeting eFPGAs at wearable, hearable, and other ultra-low-power
IoT applications.

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The block diagram showing a QuickLogic
eFPGA incorporated into a sensor hub SoC.

The
fundamental idea of integrating the FPGA resources into an SoC has been around
for many years. According to QuickLogic’s Saxe, it’s the rise in die cost as
well as SoC development cost that have finally thrust eFPGAs into the
commercial mainstream.

On
the other hand, Achronix CEO Robert Blake relates the eFPGA takeoff to the
arrival of 16-nm designs. Achronix has been evangelizing the eFPGA technology
since 2012. Blake also claims that Achronix’s Speedcore was the first eFPGA IP
being shipped to the market.

Nevertheless, the advent of eFPGA shows that the
spirit of innovation is alive and well in the semiconductor industry. Furthermore,
smaller silicon business outfits like Achronix and Flex Logix are bucking the
trend, and that’s a testament that size doesn’t matter when it comes to design
innovation.