Philips LX9000R/22, Service Manual

Page: 165 / 251

Circuit-, IC descriptions and list of abbreviations EN 165 LX9000R 9.
2001 Aug 01 4
MPEG-2 video and MPEG-audio/AC-3 audio
encoder with multiplexer
SAA6752HS
1.6 Output interface
•
Parallel interface 8-bit master/slave output
•
3-state output port
•
Glueless interfacing with IEEE 1394 chip sets (for
example, PDI 1394 L11)
•
Data Expansion Bus Interface (DEBI) interface.
1.7 Control domain
•
All control done via I
2
C-bus
•
I
2
C-bus slave transceiver up to 400 kHz
•
I
2
C-bus slave address select pin
•
Host interrupt flag pin.
1.8 Other features
•
Single external clock or single crystal 27 MHz
•
Separate 27 MHz system clock output
•
Interface voltage 3.3 V
•
TTL compatible digital outputs
•
Power supply voltage 3.3 and 2.5 V
•
Boundary Scan Test (BST) supported
•
Power-down mode
•
Single SDRAM system memory (16 Mbit@16 bit or
64 Mbit@16 bit).
2 GENERAL DESCRIPTION
2.1 General
Philips Semiconductors' second generation real time
MPEG-2 encoder, the SAA6752HS, is a highly integrated
single chip audio and video encoding solution with very
flexible multiplexing functionality. With our expertise in two
critical areas for consumer video encoding, noise filtering
and motion estimation, we have pushed the boundaries for
video quality even further, providing enhanced quality for
low bit rates and enabling increased recording times for a
given storage capacity. The SAA6752HS will also enable
a key driver for new consumer digital recording
applications; system cost reduction. By integrating all
audio encoding and multiplexing functionality we will be
moving from a three chip to a one chip system, with cost
efficient design and process technology, thus providing a
truly low cost, high quality encoding system.
The SAA6752HS/02 is intended for customers whose
application does not require the DDCE function.
The SAA6752HS gives significant advantages to
customers developing digital recording applications:
•
Fast time-to-market and low development
resources
: By adding a simple external video input
processor IC, audio analog-to-digital converter, and an
external SDRAM, analog video and audio sources are
compressed into high quality MPEG-2 video and
MPEG-1 layer 2 or AC-3 audio streams, multiplexed into
a single program or transport stream for simple
connection to various storage media or broadcast
media. Hence, making design effort for our customers a
minimum, as well as removing the need for in-depth
experience in MPEG encoding.
•
Low system host resources : All video and audio
encoding algorithms and software are run on an internal
MIPS

(1)
processor. The SAA6752HS only requires
small amount of communication from system host
processor to set up and control required encoding
parameters via I
2
C-bus.
2.2 Application ?elds
2.2.1 DVD
BASED OPTICAL DISC RECORDERS
(DVD+RW,
DVD-RW, DVD-RAM)
Emerging optical disc based recording systems target to
replace the existing consumer recording (VCR) and
playback (DVD and VCD) products. The first generation
recordable DVD based products will want to maximise
recording times for the 4.7 Gbyte storage capacity. For
these systems the SAA6752HS is critical, with its superior
noise filtering and motion estimation, in enabling high
quality at low bit rates.
Playback compatibility with existing DVD decoding
solutions will also be important, which is why the
SAA6752HS provides Dolby

digital consumer (AC-3)
audio encoding to allow playback through existing players
implementing DDCE (AC-3) decoding dominant in current
DVD platforms.
The DVD stream is based on MPEG Program Stream
(PS). The SAA6752HS directly outputs MPEG PS
compliant to the DVD standard.
(1) MIPS is a registered trademark of MIPS Technologies.