L64724 LSI Logic Corporation, L64724 Datasheet - Page 169

• Manufacturer Part Number: L64724
• Description: Satellite Receiver
• Manufacturer: LSI Logic Corporation

6.4 Descrambler Synchronization
This section describes the third-stage synchronization, which performs
Descrambler synchronization.
Figure 6.17
illustrates the Descrambler
synchronization process. The Descrambler module is only active in DVB
systems and is not used for DSS systems.
The L64724 restarts the Descrambler every 8N byte times. The L64724
aligns this restart with the complemented synchronization word that is
present in the data stream once every eight Reed-Solomon code words
(once every 8 N bytes.)
Figure 6.17 Descrambler Synchronization
Data Stream
Bit Stream
Descrambler
Data
Monitor
Module
Sync Strobes
M, N, L, K
MC,
LSC
Decision Logic
Sync Word
Configuration Parameters
For third-stage synchronization, the L64724 uses an approach very
similar to that of the second synchronization stage during the acquisition
phase to ensure proper data alignment.
Note that in this stage, any noninverted corrupted sync bytes found in
the tracking phase are replaced with the original predefined noninverted
sync byte.
Descrambler Synchronization
6-13