L64105 Datasheet, PDF (27/454 Pages) List of Unclassifed Manufacturers – AUDIO/VIDEO DECODER

The L64105 is an MPEG-2 Main Level, Main Profile decoder. It handles
image sizes up to 720 x 480 pixels with a frame rate of 30 fps for NTSC
and up to 720 x 576 pixels at 25 fps for PAL. It can also decode MPEG-1
sequences. The coded data channel may have a sustained bit rate of up
to 20 Mbits/second. As the resolution decreases, the amount and
bandwidth of SDRAM memory required for frame stores also decreases.
1.2.1 Memory Utilization
The L64105 supports direct connection to commercial SDRAM for use
as frame stores, channel buffers, and overlay memory. The L64105 uses
frame stores for frame reconstruction and display, separate video and
audio channel buffers for rate matching, and zero or more regions for
graphical overlay. This storage is combined into a single contiguous
memory space accessed over a 16-bit wide bus. In most cases this will
be one 1 M x 16-bit SDRAM, for a total memory space of 2 Mbytes. The
interface between the L64105 and SDRAM requires no external
components. The L64105 pinout allows the connection to SDRAM to be
made on a single PCB layer. During normal operation, the L64105
exclusively controls the SDRAM frame stores. However, it is possible to
access the SDRAM through the host port on the L64105 for test
verification and for access to the overlay stores and channel information.
1.2.2 Error Concealment
The L64105 detects data in the bitstream that does not meet MPEG-2
syntax or grammar rules and can flag the data for exception processing.
Hardware error handling is limited to error masking and the application
of concealment vectors in video. Audio error concealment is limited to
muting on errors and searching for error-free frames. The L64105 flags
gross errors in the bitstream due to channel buffer overrun or underrun
or to nonconformance in the bitstream. The L64105 flags the errors so
that they may be masked in the video or the audio output. The host
microcontroller may be programmed to execute mechanisms to recover
from gross errors.
L64105 Overview
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