Design Challenges: Avoiding the Pitfalls, winning the game - Xilinx

POWER MANAGEMENT
A Clear Choice
With a list of both supplier and component
criteria, HTC chose Xilinx as a preferred
vendor for low-power CPLD products.
Weighing competitors not only by price,
but by reputation of product, delivery,
quality, and attention to special needs,
Xilinx came out on top. According to
HTC, the device features were what tipped
the scale. Not only did the base power consumption
meet or exceed power budgets,
but key low-power enhancements played a
large role in part selection. “HTC has
received a substantial amount of performance
capabilities in Xilinx products,” said
Peter Chou, HTC’s president. “Their combination
of leading-edge technologies,
complete programmable system design,
and full technical service support are essential
to the success of HTC.”
When compared to other suppliers,
power consumption was basically equal;
the deciding factor was integrating differences
from other competing products.
Integrated low-power features gave HTC
designers a creative method to both
increase battery life and phone features.
By using clock features, the designers
eliminated external oscillators and
reduced costs. These clocking features
also helped reduce overall power consumption
and increase battery life. With
this one feature, they reduced board space
without using additional power.
Another low-power feature that
helped overall battery life was input gating.
This technique has been used on
other products, but Xilinx was one of the
first companies to incorporate it in a
CPLD. This feature helped reduce over-
2001 2002 2003 2004 2005 2006 2007 2008
Entry Level 97.7 95.4 84.2 68.6 52.5 40.1 29.3 20.8
Midrange Feature 1.9 3.1 10.6 21.1 28.0 31.4 32.2 34.3
High End 0.1 0.6 3.4 7.3 12.6 19.0 26.4 30.3
Converged
Mobile Device 0.4 0.8 1.8 3.0 7.0 9.5 12.0 14.6
Table 1 – Worldwide mobile phone shipment share by feature tier, 2001-2008 (%) (Data supplied by
IDC – worldwide mobile phone 2005-2008 forecast by feature tier)
Operating System Units Shipped Market Share
Windows CE 1,759,497 45.5%
Palm OS 1,301,740 33.7%
RIM 698,000 18.1%
Linux 24,300 0.6%
Others 82,000 2.1%
Table 2 – Shipment of PDAs by operating system worldwide
HTC has embraced low-power CPLDs with a
passion, taking advantage of the features
offered by CoolRunner-II products ...
all dynamic power consumption
by powering down
circuits to their standby or
quiescent state. By turning
off circuits that are only used
part of the time, battery life
can be extended well beyond
a competitor’s product with
the same features.
Device integration also
added a key advantage to
HTC’s designs. By using a single device
to shift voltage levels for certain circuits,
discrete devices were eliminated. Plus,
the availability of small chip-scale packages
saved board space when compared to
discrete devices. By consolidating various
functions into a single reprogrammable
device, HTC saved layout problems
when faced with high integration goals.
Also, by condensing signal paths on a
PCB layer, layout became much easier.
Faster Designs with WebPACK
To make use of special features as HTC
has, you need to be able to implement
them without extra effort. Low-power
features such as clock frequency scaling,
signal gating, and hysteresis are easy to
use and have example code listed in
ISE WebPACK software. This
enabled HTC to turn designs around
faster with the confidence that all critical
timing and power consumption goals
would be met.
The best part of Xilinx WebPACK software
is that the features are free. Not only
can you design with high-level languages
like VHDL and Verilog, but functional
and timing verification tools work flawlessly.
Plus, the XPower power analysis tool
gives you a reliable estimation of how
much power will be consumed at each
point of the operation. This easy-to-use
software tool gave the HTC designers confidence
that the results they saw through
simulation were the results they measured
in actual designs. For HTC, precisely
knowing what to expect let them pack the
most into their designs.
Conclusion
HTC has embraced low-power CPLDs
with a passion, taking advantage of the
features offered by CoolRunner-II products
and obtaining a larger share of midto
high-end handset sales than their competitors.
With more users embracing
more features, HTC is well positioned to
continue their leadership and maintain
growth in emerging markets. Through
the use of Xilinx silicon products and
software tools, HTC will continue to
design innovative solutions and deliver
these products on time.
To further explore the Xilinx family of
CPLDs, visit www.xilinx.com/cpld/
index.htm. To see HTC’s line of handsets,
visit www.htc.com.tw.
58 Xcell Journal Third Quarter 2005