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25 Wed May 28 17:37:25 1997
Draft 1/21/97
L64007 MPEG-2, DVB, JSAT Transport Demultiplexer Technical Manual
4-25
PRE.4 for Rev. D
Copyright 1997 by LSI Logic Corporation. All rights reserved.
Sync lock and unlock management is handled internally.
When set to 1, the channel decoder interface uses the
external pin CDSYNC to indicate the start of the transport
packet. After reset, the bit is 0.
START
Start or Stop Channel Decoder Operation
0
When set to 1, this bit starts the operation of the channel
decoder interface block. When reset to 0, the channel
decoder operation is stopped. If it is stopped after Sync
has been acquired, the actual stop is at the end of trans-
port packet. An interrupt is sent to the host when the
channel halts and the CHALT bit in the CSR is set to 1.
After reset the bit is reset to 0.
4.8.2
A/V Control
Register (AVCR)
The AVCR is a 16-bit read and write register that controls the operation
of the audio/video channel decoder interface.
RES
Reserved
[15:11]
These bits are reserved.
AV_RATIO
Audio/Video Output Channel Rate Ratio
[10:5]
This 6-bit eld determines the data rate ratio between the
video data and the audio data. The specied value deter-
mines how many bits or bytes of video data are output
continuously before one bit or byte of audio data is out-
put. Video or audio data is clocked out only if the respec-
tive request pins (AREQ, VREQ) are active, and the
respective transport buffers are not empty. If, at the time
of clocking out audio data, there is no request or the
transport buffer is empty, the A/V ratio process restarts
from the beginning.
After reset, the AV_RATIO eld value is 00000.
15
11
10
5
4
3
2 1
0
RES
AV RATIO
SYNC
DEL
DELAY
AV RATE