Siemens scan converter with embedded DRAM...................
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Siemens bases digital-TV converter on embedded DRAM
By Junko Yoshida
CUPERTINO, Calif. — In pursuit of the volume
consumer digital TV market, Siemens
Microelectronics Inc. has rolled out a scan rate
conversion IC designed to convert NTSC
interlaced images into progressive scan output.
The chip, which is based on an embedded DRAM,
is "critical for TV manufacturers who want to
ensure that their mainstream, large-screen digital
TV sets — besides offering digital SDTV and
HDTV images — will continue to reproduce high
quality analog NTSC pictures," said Michael
McDonald, U.S. consumer marketing manager for
Siemens Microelectronics, based here.
Siemens is working on a variety of silicon solutions
to help the digital HDTV market take off, said
McDonald. The company's new SDA9400
scan-rate converter is "not a one-shot device," he
said. "This will be followed by a series of other
chips currently in development."
The SDA9400 up-converts 525 interlaced NTSC
pictures to 525 progressive pictures, offering a
31.5-kHz line frequency output. While doubling the
lines to eliminate visible line structure on big screen
televisions, the chip incorporates newly developed
algorithms that minimize the loss of quality or
vertical resolution — common artifacts often seen
in current low-cost line-doubler solutions,
McDonald said.
By offering 31.4-kHz line frequency (as opposed
to 15.75-kHz for NTSC), the Siemens converter
lets TV system vendors design a large-screen
digital TV without resorting to a costly multi-scan
rate monitor. Such a variable scanning rate feature
is available on computer displays with relatively
small screens, but such a feature would be
prohibitively costly and complex on a large-screen
display due to the required deflection circuitry and
scanning gun.
Siemens' SDA9400 is aimed at first-generation
digital TV designs that will display 1080i. "We are
finding that most TV manufacturers today are
building their digital TV capable of displaying
1080i," McDonald said. "They want to use a
simpler deflection circuitry, designed to handle
either a single or a very small range of frequencies."
By providing 525 progressive pictures at a
31.5-kHz line frequency, "our chip is offering a
frequency very similar to the HDTV display rates
of 1080i [32.4 kHz]," he added.
Gerry Kaufhold, principal analyst at In-Stat Inc.,
(Scottsdale, Ariz.) said that "presumably, every
HDTV could ship with this new Siemens chip.
"This chip doesn't displace HDTV circuitry, but it
adds NTSC capability to digital TV while keeping
the overall digital TV system cost down," Kaufhold
said.
The Siemens scan-rate converter is set apart by its
integration, its proprietary algorithms and by its
cost, McDonald said. Siemens engineers have
built, for the first time, the scan-rate conversion IC
onto an embedded DRAM. The 5.2 Mbits of
memory on the chip reduces the total chip count by
eliminating the need for a separate frame buffer
within a system. Further, it helps lower costs
because system vendors say it is becoming harder
to find a smaller memory, McDonald said. While
other chip vendors have talked about using
embedded memory for this type of application,
Siemens is the first to realize the goal, he said.
"We've been making picture-in-picture ICs and
some ASICs with embedded DRAM over four
years now," said McDonald. "We think we've
reached a point where we are comfortable in
offering our customers cost effective embedded
memory solutions."
The SDA9400 leverages proprietary
image-enhancing algorithms that Siemens jointly
developed with the University of Dortmund and the
Heinrich Hertz Institute in Germany. "Compared to
other line-doubling solutions on the market, our
chip — while repeating each line — neither
defocuses images nor loses vertical resolution very
much," said McDonald.
In converting interlaced images to the
progressive-scan mode, the Siemens chip actually
implements pixel-by-pixel analysis to determine
first whether there is motion, and if so, to then
measure the amount of noise caused by that
motion. The chip then applies an appropriate
algorithm to eliminate the noise.
The SDA9400 is not intended for applications in
the high-end broadcast market, McDonald said.
"Let's not kid ourselves. This is not designed for
luxurious, professional line-doubler products like
those by Faroudja," he said. Instead, Siemens
wants "to deliver good quality up-converted 525
progressive pictures at a reasonable cost for a high
volume consumer digital TV market," he said.
The chip also features vertical and horizontal
decimation capabilities to enable
split-screen/double-window viewing, and has
vertical interpolation to eliminate the black bars
used in letterbox formatting.
Samples of the SDA9400 are available today, with
mass production slated for the first quarter of
1999. The chip is fabbed in Dresden, Germany
using a 0.35-micron embedded DRAM process.
Back-end production takes place at Siemens' plant
in Singapore. The SDA9400 is priced at $40 each
in 10,000-piece quantities. |
