IBM39STB032xx
IBM39STB034xx
STB032xx and STB034xx Digital Set-Top Box Integrated Controllers
Preliminary
(serial), or 88-Mbps (parallel) or 60-Mbps (serial) with the optional descrambler. Packet Identifier (PID) filter-
ing is based on 32 programmable entries with detection and notification of errors and lost packets. Hardware-
based clock recovery on program clock references (PCRs) reduces processor load by:
- Calculating clock difference between PCR and System Time Clock (STC)
- Modulating output to drive an external VCXO
- Using an optional internal clock-recovery algorithm based on clock difference
Transport and descrambler features include:
• Internal DVB (1.0 or 1.1) descrambler, including filtering and storage of eight control word pairs
• Auxiliary output port for real-time data transfers:
- 8-bit mode at 1X, 1/2X, 1/3X, 1/4X and 1/8X of the system clock speed
• Table section filtering:
- 64 separate 4-byte filter blocks with bit-level masking with full match/not match capability
- Multiple filters can be linked to extend filtering depth in 4-byte increments
- Multiple filters per PID
- Filters program-specific information (PSI), service information (SI), private tables
- Handles multiple sections per packet and sections that span packets
- Optional CRC checking of section data
• Selective routing of some or all packet data to system memory:
- Based on 32 separate queues (one per PID)
- Routing entire packets, payloads, adaptation fields, table sections (after filtering) and private data
• Direct transfer of audio / video (PES) data to decoders
• Simplified channel changes, time-base changes and error flagging / concealment through direct commu-
nication with decoders
• Interface for a Transport Assist Processor to provide additional processing:
- Extended filtering / parsing of tables, private data, adaptation fields, and PES headers
- Ability to selectively route alternative data fields to system memory
MPEG-2/Dolby Digital Audio Decoder
The Audio Decoder receives and decodes either ES (Elementary Stream) or PES (Packetized Elementary
Stream) audio data. The audio compute engine is a generic DSP processor that decodes MPEG, Dolby Digi-
1
tal , or 16-, 18- or 20-bit unformatted Pulse Code Modulation (PCM) audio data via individual software pro-
grams.
The host processor downloads each program load to the Audio Decoder following initialization. The Audio
Decoder generates up to two channels of decoded PCM for MPEG and PCM audio playback output. It pro-
vides 2-channel MPEG audio output and 6-channel Dolby Digital down-mixed to either two channels or six
channels of Dolby Digital output. Unpacketized PCM (UPCM) plays back at sampling frequencies of 16 kHz,
22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, and 48 kHz, along with quantization sample width selections of 16-, 18-
or 20-bit input and 16 or 20-bit output.
The Audio Decoder:
• Decodes Dolby Digital, described in the ATSC Specification “Digital Audio Compression” (A/52).
• Decodes MPEG-1 and MPEG-2 audio (Layers I and II) and 2-channel output, including single channel,
stereo, joint stereo, and dual channel modes.
1. This feature available only on STB03x1x, Dolby Digital license required
Architecture and Subsystem Information
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STB03_sds_041800.fm.01
April 18, 2000
IBM [ IBM ]
