TL855
Professional Digital TV Decoder
All Format video/graphics solution for studio or professional quality equipment
GLOBAL AND SCALABLE ARCHITECTURE
The TL855 is an integrated MPEG-2 MP@HL 4:2:2 video decoder, display processor and graphics accelerator for professional
advanced Digital Television. It complies with all ATSC/ARIB/DVB-HD/DIRECTV®-HD recommended performance metrics and
supports direct video output to a variety of display types. It performs professional quality decoding (4:2:2) of a single HD program
(MP@HL). An integrated graphics accelerator renders text and graphics to an independent on-screen display (OSD) bitmap.
The IC buffers the audio data, allowing the use of a standard Dolby Digital (AC-3) decoder chip or software on a host CPU for
audio decoding.
The TL855 accepts MPEG compressed data encoded in the 4:2:2 format. Four Y, two Cb and two Cr values are generated for
every four pixels decoded. Compared to 4:2:0 decoding, 4:2:2 decoding generates two extra chroma components requiring a
considerable increase in performance over 4:2:0 consumer decoders. Therefore
the TL855 memory interface, the MPEG decoder core engine and the display
controller must be highly tuned for 4:2:2 processing. The memory interface has
twice the buffering of conventional 4:2:0 decoders to handle the extra amount of
chroma component during writes and reads. The MPEG decoder engine decodes
the extra chroma values. The display controller accepts 4:2:2 data from the SDRAM
as decoded by the MPEG decoder engine, then displays this higher quality video
on the screen.
The TL855 is able to process all ATSC, DVB-HD and ARIB formats (and other
worldwide and proprietary decoding such as DIRECTV) in high quality 4:2:2 video
and then display the resultant video at this quality. In addition to the MPEG-2 4:2:2 decode, the TL850 performs format conversion
from any ATSC format to any other ATSC format (including many non-standard resolutions). An on-chip 2D graphics accelerator
provides TV-centric graphics and OSD to complement the video quality. A PCI interface allows ease of interfacing to a variety of
common off-the-shelf components suitable for professional systems. In addition to these functions the TL855 can be programmed
into a 4:2:0 mode of operation.
16MB - 64MB
SDRAM
RGB or
YPbPr
and Sync
64
HDTV
2
MPEG Transport Data
TL855
Digital RF
I S
QPSK, QAM or
VSB Receiver
5.1 Channel
5.1 Channel
Audio DACs
8
!
IEC958
Studio Source
Audio Decoder
32
PCI Bus
TL855 SYSTEM DIAGRAM