PS20251 Datasheet, PDF (16/25 Pages) List of Unclassifed Manufacturers – Dual COFDM demodulator with PID filters and MRC diversity

PS20251
3.22PID Filter
The packet identifier filter has 2 main functions. It filters out unwanted MPEG data by discarding MPEG
packets that do not have a valid PID. By reducing the total amount of MPEG data packets, the two
channels of the dual demodulator can be output on a single MPEG stream. In order for the MPEG
processor to determine which channel the packet has come from, the PID values in each channel may
be modified, to ensure they have a unique PID.
Notes:
• The PID filter handles 2 data streams, one for each DVB-T demodulator.
• The PID filter function is controlled from channel 1 only.
• Bit 0 (PF1_EN) and 1 (PF2_EN) of PFILT_EN_Ch1 must both be set to 1 for PID filtering to take
place.
• The multiplexed MPEG output is enabled whenever the PID filters are enabled.
• The channel 1 MPEG output is disabled whenever the PID filters are enabled but channel 2 MPEG
output will continue to be output unless turned off through MDO_EN.
• The multiplexed MPEG output can be either serial or parallel, set by SER_CLK_Ch1
in MPGO_Ch1 register.
• The normal, non-multiplexed, MPEG outputs can also be serial or parallel BUT if the PID filters
are to be used the outputs MUST be set to parallel.
PLESSEY SEMICONDUCTORS LTD
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