Opportunities andChallenges for SmarterMobile DevicesNamsung (Stephen) Woo
Samsung Electronics
h FIRST OF ALL, I would like to congratulate all
EDA professionals for the 50th anniversary of the
Design Automation Conference (DAC). Since the
beginning of DAC, both semiconductor industry and
EDA industry have grown a lot. If we consider the
revenue of last twenty years (1993–
2012) alone, the semiconductor indus-
try has grown 3.8 times (from $66B to
$251B) and the EDA industry 5.2 times
(from $1.3B to $6.7B).
Looking back the papers presented
at DAC, we can easily find that DAC has
been leading and supporting the de-
sign and manufacturing of semicon-
ductor solution. In 1980’s, the areas of physical
design, circuit simulation and testing saw many
papers. In 2000’s, papers in the areas of low power
design, verification and embedded systems led DAC.
In the last several years, we found strong interest in
the areas of thermal issues (for highly integrated
chips) and variation tolerance (for advanced sili-
con manufacturing). Interestingly, these two areas
Editor’s notes:This article is based on a keynote address presented by the author at the50th DAC. It discusses the state-of-the-art in semiconductor technology andits interaction with smart mobile devices, wide I/O memory access andflexible displays.
VYervant Zorian, Synopsys
Namsung (Stephen) Woo gives his keynote address.
IEEE Design & Test2168-2356/14 B 2014 IEEE Copublished by the IEEE CEDA, IEEE CASS, IEEE SSCS, and TTTC56
50 Years of DAC: What Lies Ahead
Digital Object Identifier 10.1109/MDAT.2014.2315955
Date of current version: 19 May 2014.
address key technical challenges of semiconductor
solutions for smart mobile devices.
This article will first examine recent trends of
smart mobile devices and their influence on semi-
conductor industry. Then, we will describe several
new aspects of smarter devices (i.e., future wave of
smart devices) and their impact on semiconductor
and EDA technology.
Mobile devices andsemiconductor industry
The driving force of the semiconductor industry
has recently changed from PC to mobile device. For
instance, the number of smart phones sold globally
in 2013 is expected to be 930 million units, and the
number will grow to 1.1 billion units in 2014. Tablets
are also growing fast: from 210 million units in 2013
to 290 million units in 2014.
Along with the volume increase, smart devices
have seen enhanced computing power for complex
applications. The mobile application processor
(AP), which runs application software of smart de-
vices, contains CPU core(s), graphics core(s), multi-
media core(s) and other IP blocks in one silicon die.
Since mobile devices are running on battery, mobile
AP has to consume low energy including low stand-
by current. As a result, mobile AP is typically built on
a low-power (and, as a result, low-speed) silicon
process.
Then, how can we get higher performance of
mobile AP while consuming low energy? This diffi-
cult goal has been achieved mostly by three areas of
development: advanced CPU/SOC architecture, so-
phisticated circuit design (with the help of EDA
technology) and advanced silicon process.
Figure 1 shows a brief history of mobile AP for
smart phones. The X-axis is the year in which a
mobile AP was put in production, while the Y-axis
shows the performance in terms of DMIPS (Dhrys-
tone Million Instructions per Second). In 2009, for
the first time in mobile AP history, a mobile AP
recorded 1.0 GHz clock speedwith low-power 45 nm
silicon process. In 2010 and 2011, mobile AP with
dual CPU cores and quad CPU cores appeared, re-
spectively. In 2012/13, mobile APs with eight CPU
cores, four big cores and four little cores, were de-
veloped and used in smart phones [1]. As shown in
the figure, the computing performance measured in
DMIPS has been increasing every year.
In order to offer high computing power at low
energy consumption, many design techniques have
been developed, and DVFS (Dynamic Voltage and
Frequency Scaling) is one of them. Its goal is to
adjust mobile AP’s supply voltage (Vdd) according
Figure 1. Progress of mobile AP since 2008.
March/April 2014 57
to its workload. Figure 2 shows an operation
example of DVFS, in which high Vdd is used when
AP deals with heavy workload and low Vdd when
workload is light. In reality, AP’s firmware controls a
PMIC (power management integrated circuit) that
provides Vdd to AP.
Silicon process plays an important role to
support mobile AP. Figure 3 shows the progress of
CMOS process technology for mobile applications
during 2000–2013. The poly-SiOn technology has
been used for the 45 nm process, and since then,
high-K/metal-gate (HK/MG) technology has been
adopted since 32/28 nm process. For 14 nm process
(in some cases, 16 nm process), a 3D transistor,
called FinFET, is being used.
Other areas which have experienced dramatic
growth in smart devices include camera sensors and
display driver chips. For instance, in the CMOS-
based camera sensor chips for smart phones, the
number of pixels in one sensor chip grew from
1.3M pixels (in 2005) to 13M pixels (in 2012), while
the size of camera sensor chip remains basically
the same.
Smarter devices: The next wave ofsmart mobile devices
The next wave of smart mobile devices, ‘‘smarter’’
devices, will offer much better user experience (e.g.,
gesture recognition) and much broader solutions
Figure 3. Progress of CMOS Process Technology.
Figure 2. DVFS operation.
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50 Years of DAC: What Lies Ahead
(e.g., context-sensitive comput-
ing). In this article, however, we
will look at only two areas
related to technology.
Wide IO for higher bandwidthbetween AP and memory
Three elements of smarter
devices drive up the bandwidth
requirement between mobile
AP and memory: 1) higher
data rate of air interface (e.g.,
LTE-A), 2) higher graphics per-
formance, and 3) higher display
resolution (e.g., UHD). The
‘‘Wide IO’’ technology, in which Memory is
connected to AP by TSV (Through Silicon Via), is
the best known approach for high bandwidth
between AP and Memory.
Figure 4 shows TSV in Wide IO and a way of
putting memory die on AP die. In addition to high
bandwidth, the Wide IO technology provides low-
energy memory access because of the closeness of
memory to AP.
The Wide IO technology has recently been real-
ized in industry. The ‘‘V’’ system, which offers 512
data lines between AP and mobile DRAM via TSV, is
now running real applications [2]. Experimental
data show that the current implementation of Wide
IO offers 14% higher bandwidth than LPDDR3 and
consumes 60% less energy than LPDDR3.
One challenge of the Wide IO technology is
complex memory architecture. That is, the mobile
AP has to deal with two types of memory (i.e., inter-
nal memory connected by TSV and external mem-
ory) with different access time. Mobile software has
to be intelligent if it wants to utilize internal memory
as much as possible. Some research groups have
made good progress in managing this complex
memory system in smarter devices.
Flexible displayThe display resolution of smart mobile devices
has been moving up, and current smart phones offer
full HD (FHD) resolution. In the near future, UHD
display will be used in high-end smarter devices.
One disruptive display technology for smarter
devices is ‘‘flexible’’ display. As demonstrated at this
year’s (2013) CES show [3], flexible display is
working well at laboratories. Recently, in 3Q13, an
early form of flexible display, called ‘‘curved’’display,
was adopted in two smart phone models from two
companies. It is reasonable to expect smarter
devices with ‘‘fully’’ flexible display in the next
couple of years.
If we have fully flexible display at smarter
devices, the other electronics part (i.e., a PCB with
multiple chips on it) of smart devices must also
change. That is, if the current form of PCB does not
change, the advantages of flexible display will not
be fully exploited.
For the future path of electronics portion in
smarter devices with flexible display, we can learn
lessons from the current display driver IC. As shown
in Figure 5, the current display driver IC’s are put on
a plastic film, which is connected to a display.
If we can reduce the total number of chips in
smarter devices from more than dozen (which is the
case with the current smart devices) to one or two,
Figure 5. Display driver IC on a plastic connectedto a display.
Figure 4. Wide IO technology.
March/April 2014 59
and if we can put them on a plastic film, we would
be able to build smarter devices that fully utilize
flexible display. If we get this solution, we will have
SOP (System on Plastic) or SOF (System on Film)
that works naturally with flexible display.
SMART MOBILE DEVICES have contributed to the
growth of semiconductor industry, and the trend will
continue in the near future. In this article, we de-
scribed an interaction between smart mobile de-
vices and semiconductor solution; we showed that
high-performance and low-energy mobile AP’s
allowed smart phones to progress, and vice versa.
We also touched smarter devices (i.e., the next
wave of smart mobile devices) and two technical
initiatives, wide IO and flexible display, for them. For
each initiative, we introduced the most recent
result(s) and discussed future paths.
EDA technology has been helping semiconduc-
tor industry (both in design and manufacturing)
which, in turn, contributed to smart devices. We
hope this virtuous circle continue in the future. h
h References[1] AP Data Book, System LSI, Samsung Semiconductor,
2010–2013.
[2] ‘‘V’’ System With Wide IO Solution, System LSI,
Samsung Semiconductor, 2013.
[3] Keynote Talk by This Author at CES 2013, Las Vegas,
NV, USA, Jan. 2013.
Namsung (Stephen) Woo is the president ofSystem LSI at Samsung Electronics, San Diego, CA,USA. Before joining Samsung, he worked at BellLaboratories, Murray Hill, NJ, USA and TexasInstruments, San Diego, CA, USA.
h Direct questions and comments about this articleto Namsung (Stephen) Woo, System LSI, SamsungElectronics.
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50 Years of DAC: What Lies Ahead