GS1582-IBE3 View Datasheet(PDF) - Semtech Corporation

Part Name

Description

Manufacturer

GS1582-IBE3

Multi-Rate Serializer with Cable Driver, Audio Multiplexer and ClockCleaner™

Semtech Corporation 

4.7.4 Audio Packet Delete

Ancillary data packets with non-audio data ID words, such as arbitrary, EDH, SDTI

header and SMPTE 352M, will not be deleted from the data stream. On lines where

SMPTE 352M or SDTI header packets exist, the audio data packets must be contiguous

to the 352M and SDTI packets in SD mode. For HD formats, the audio data packets must

always be contiguous after the two EAV CRC words. If this is not the case, all existing

audio data and control packets will be deleted.

When the EN_CASCADE host interface bit is set HIGH, all existing audio data and

control packets will remain in the video stream.

When the AGR bit in the host interface is set HIGH, audio group replacement mode is

selected. In this mode, existing audio data and control packets will not be deleted from

the data stream with the exception of any packets of groups being replaced.

In cases where the ADF is not placed immediately after the CRC or EAV words, or there

are gaps between the packets, the audio core will delete all existing audio data and

control packets, regardless of the EN_CASCADE or AGR setting. Figure 4-11 shows an

example of correct and incorrect placement of ancillary data packets for a SD format.

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Correct placement of Ancillary Data within HANC Space

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HANC with space between EAV and Ancillary Data (Audio Packets will be deleted)

Figure 4-11: Ancillary Data Packet Placement Example

4.7.5 Arbitrary, SMPTE 352M & EDH Packet Detect

The audio multiplexer detects the presence of any arbitrary data packets. If present,

these packets will be removed and stored for re-insertion after audio packets have been

embedded. If there is insufficient HANC space available, the arbitrary data packet will

be discarded.

To detect the arbitrary data packet, the audio core looks for any ancillary data packets

which have a DID other than audio, extended audio, control, SDTI header, SMPTE 352M

or EDH packets. Arbitrary data packets and formatting are defined in SMPTE 291M.

Arbitrary data packets are only present on the luma channel of the HD video input.

All EDH processing is carried out following the audio core, as the CRC's will require

updating. The audio core detects the presence of EDH packets in the HANC region.

These packets are preserved and re-embedded after multiplexing of audio packets,

according to RP 165. The audio core does not perform EDH CRC calculation and flag

updates.

GS1582 Multi-Rate Serializer with Cable Driver, Audio

Multiplexer and ClockCleanerTM

Data Sheet

40117 - 4

December 2011

40 of 115

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