ETC L64781

L64781 Single-Chip COFDM Receiver
DVB-T Compliant Demodulation
The L64781, the second chip in LSI Logic’s family of highly integrated, highperformance solutions for digital terrestrial TV broadcast, is a fully integrated,
single-chip COFDM (Coded Orthogonal Frequency Division Multiplex) demodulator. The L64781 channel receiver is fully compliant with DVB-T standards
and follows the highly successful L64780, widely used by manufacturers producing
set-top boxes for the current European digital terrestrial market.
Proven Solution for Fast Time to Market
The completeness of this solution enables a spectrum of applications for both
2K-only broadcasting in the UK, and 8K multiple or single frequency network
broadcasting in Scandinavia, Spain and other emerging markets such as Singapore.
Its robust channel equalizer and doppler immunity also allow manufacturers to
use this solution in mobile DVB-T applications.
The L64781 comprises the COFDM demodulator, a DVB-compliant FEC decoder
and a 10-bit analog-to-digital converter. With this device, digital set-top box and
TV manufacturers have a ready-proven, high-performance technology to bring
DTT-enabled products to market quickly and cost effectively.
The L64781 is a fully variable rate demodulator, supporting 6, 7 and 8MHz
channels. The chip is highly integrated (both timing and frequency loops are
fully digital) and capable of delivering up to 31.7 Mbit/sec. This represents more
than 20 movie channels or 4 live video channels in each 8MHz channel
previously filled by a single analog PAL channel.
The L64781, LSI Logic’s fully integrated single-chip COFDM demodulator, is fully
compliant to the DVB-T standard for digital terrestrial television in Europe
The L64781 interfaces seamlessly to a tuner
to provide an error corrected MPEG2-TS.
This gives set-top box and TV manufacturers
a complete digital terrestrial TV receiver and
enables fast time-to-market
L64781 Single-Chip COFDM Receiver
2K and 8K FFT size
Includes FEC and 10-bit ADC
Digital timing recovery
6MHz, 7MHz and 8MHz variable bandwidth
• Implements non-hierarchical QPSK, 16-QAM
and 64-QAM constellations and hierarchical
constellations with scale factors a = 1, 2 and 4
• Viterbi code rates 1/2, 2/3, 3/4, 5/6, 7/8
• Guard intervals: 1/4, 1/8, 1/16, 1/32
• Includes digital common phase error
correction (CPE)
• Channel state information for protection
against multipath and interference
• NIM board with COFDM demodulator, tuner
The L64781 applies all error correcting codes to deliver an error-free MPEG2 transport stream to the
source decoding chip
and serial host interface
• Low IF (4.57MHz) sampling with digital
baseband down-conversion allowing for
single ADC
• Serial microprocessor interface
Technical Description
The L64781 implements all operational modes specified in the DVB-T specification,
i.e., 2K and 8K FFT, non-hierarchical and hierarchical modulations, all guard
interval sizes and Viterbi code rates. The chip samples a low IF signal (IF = 4.57 MHz)
and converts it digitally into baseband.
The L64781 then applies all digital processing steps to extract the data from the
received signal, i.e., FFT, timing and frequency synchronization, channel estimation
and equalization, generation of optimal soft decisions using the channel state
information, symbol and bit de-interleaving. It also extracts the system information
carried by the TPS pilots, stores it into internal registers and delivers it to an
external micro controller. The L64781 finally applies all error correcting codes to
deliver an error-free MPEG2 transport stream to the source decoding chip.
The L64781 is a highly integrated device that contains both digital timing and
frequency loops. No external components are required to operate the demodulation,
and only a low cost XO is required. If the tuner requires an analog feedback, the
device also provides means for analog timing and frequency control signals in the
form of one wire sigma-delta modulated signals. This requires minimal external
circuitry and interconnection.
It implements a standard serial micro controller interface.
Complete Solution for Fast Time to Market
To accelerate development of set-top box solutions, the L64781 is available with
a developer’s kit, allowing manufacturers to select the option best suited to their
target market and application requirements. The kit provides the hardware and
software components to shorten development cycles and to ensure a fast time to
market. The powerful Windows 95 Graphical User Interface allows manufacturers
to easily perform validation tests and store results in an intuitive way.
• Fully integrated single-chip COFDM DVB-T
compliant demodulator for fast time-tomarket
• Systems expertise and support gained from
first-generation chip
• Minimal effort required for implementation in
a complete COFDM system
• Rapid time and frequency synchronization
• Excellent mobile reception (channel equalizer
handling varying channels)
• Reduced systems costs through common
phase error compensation
• Near theory high-performance demodulation
• Fast access to circuit evaluation with local
field application engineering support
• Simple microprocessor interface resulting
from high automation
NIM781 Evaluation Board provides full capabilities for accelerated development and fast time to market
The developer’s kit consists of a complete evaluation board with a PC interface
and MPEG2 transport stream output. Software to enable system testing and code
optimization is included, along with a manual that provides test and evaluation
information and a PC board layout. It also contains a GUI under Windows 95/97.
The NIM781 board also has a seamless interface to LSI Logic’s Set-top Box
Development Platform.
Components of LSI Logic’s L64781 Developer’s Kit
Evaluation board with PC interface and MPEG2-TS output
Complete documentation
Software, including driver and GUI interface under Windows
Board layout
Bill of materials
L64781 Single-Chip COFDM Receiver
LSI Logic Integra® Set-top Development Platform
For designers developing a set-top box solution using the L64781 chip, LSI Logic
offers the Integra Set-top Development Platform. This provides a complete development environment, including complementary devices, such as the single-chip
SC2000 source decoder. It permits designers to implement a complete two-chip
set-top box solution.
As an Integra component, the L64781 features all the advantages of this nextgeneration platform:
• Evolutionary product strategy, ensuring a seamless and cost-effective
migration path to the future
• Software compatibility with legacy and new chipsets
• Support for open, international industry standards
The L64780 and L64781 were jointly developed by LSI Logic and the BBC. The
BBC, who has been a key influencer in the acceptance of the European DVB-T
standard, has implemented hardware prototypes of the COFDM modem and
successfully tested it over experimental broadcasts in the UK and other European
In 1998, tests and field trials carried out by the BBC and other validation groups
verified performance and interoperability of the new system and highlighted the
L64780 as the best performing chipset in the marketplace.
The L64781 has subsequently benefited from various field validations carried out
on the L64780, ensuring a high-performance device.
For more information please call:
LSI Logic Corporation
North American Headquarters, Milpitas, CA
Tel: 800 574 4286
North America
Milpitas, CA
Phone: 1-408-490-8000
Fax: 1-408-490-8590
Quebec, Canada
Phone: 1-514-426-5011
Fax: 1-514-426-7119
Crawley, West Sussex
United Kingdom
Phone: 44-1293-651100
Fax: 44-1293-651119
Beijing, China
Phone: 86-10-626-38296
Fax: 86-10-626-38322
Chengdu, China
Phone: 86-28-6713-150
Fax: 86-28-6713-694
Tokyo, Japan
Phone: 81-3-5463-7811
Fax: 81-3-5463-7825
Seoul, Korea
Phone: 82-2-561-9011
Fax: 82-2-561-9021
Taipei, Taiwan
Phone: 886-22-517-4938
Fax: 886-22-517-4937
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Copyright ©2000 by LSI Logic Corporation.
All rights reserved.
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