Philips SACD 1000/001 Service Manual page 89

Circuit-, IC descriptions and list of abbreviations
STi5505 (Rev. Ax)
I - GENERAL DESCRIPTION (continued)
The main features of the decoder core are :
- Decodes 5.1 Dolby AC-3 Digital surround,
- Output to 6 channels. Downmix modes : 1, 2, 3
or 4 channels for MPEG and AC-3 streams,
- Karaoke mode for DVD. MPEG-2 capable, AC-3
capable,
- MPEG-1, 2-channel audio decoder layers 1 and 2,
- MPEG-2, 6-channel audio decoder layer 2,
- PCM : transparent. downsampling 96 to 48 kHz,
- Accepts MPEG-2 PES stream format for : MPEG-
2, MPEG-1, Dolby AC-3 and Linear PCM,
- IEC6958 Output Interface,
- CD-DA PCM format (subcode output in IEC6958
user data),
- Downmix for Dolby Pro Logic compatible outputs
for AC-3 and MPEG-2 (Pro Logic encoder),
- Pro Logic decoder,
- PLL for Internal 44.1 and 48kHz PCM clock
generation,
- On chip pink noise generator.
I.5 - High Performance On-Screen Display
The graphics performance of the STi5505 sup-
ports the new requirements for intelligent program
guides and interactive applications.
The display interface supports up to 256 colors for
each OSD region and a transparency feature al-
lows mixing of video with the OSD. Fast access
graphics and many other additional features are
available and are supported by a graphics library.
Very high system performance is obtained by
closely coupling the ST20 RISC processor and
cache with the MPEG audio/video core and display
memory.
Low latency RISC access and DMA engines allow
rapid construction of bit maps.
I.6 - PAL/NTSC Encoder
The STi5505 integrates a PAL/NTSC encoder. It
converts the digital MPEG/Sub Picture/OSD
stream into a standard analog baseband
PAL/NTSC signal and into RGB analog compo-
nents. Six analog output pins are available on
which it is possible to output CVBS, S-VHS (Y/C)
and RGB formats.
SACD 1000
The encoder handles interlaced and non-interlaced
mode.
It can perform Closed Captions, CGMS or Teletext
encoding and allows Macrovision 7.01/6.1 copy
protection.
The encoder supports both master and slave
modes for synchronization.
I.7 - Memory Interfaces
The STi5505 has been designed to minimize sys-
tem costs by enabling various memory savings.
Two kinds of memory interfaces are used on the
STi5505 : a programmable External Memory Inter-
face (EMI) and a high performance SDRAM inter-
face.
The External Memory Interface supports several
address ranges (memory banks). In each bank, a
set of signals are entirely programmable and can
be used to map 8/16 bits peripherals such as Front
End channel ICs in DVD applications.
The EMI contains a zero glue logic DRAM and a
low-cost EPROM interface.
This interface can be programmed to interface very
easily peripherals.
The SDRAM memory interface supports gluelessly
125 MHz SDRAMs providing the adequate band-
withs to achieve MPEG decoding and display, OSD
drawing and display, and general system use.
Memory savings can be realized on ROM require-
ments too : the ST20 VL-RISC micro-core has the
highest code density of any 32 bit CPU, leading to
the lowest cost program ROM.
I.8 - Front-End Interface
The STi5505 's front end interface accepts :
- DVD, VCD and CD-DA sectors,
- DVB-DSS transport stream.
In DVD mode, DVD, VCD and CD-DA information
can be input into STi5505 through a serial interface
or a generic parallel interface.
In serial mode, data are captured and filtered from
I2S and V4 interfaces by an internal sector proces-
sor. V4 interface is used to capture VCD and CD-
DA subcode information. In parallel mode, sector
processor is bypassed.
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