GS3470 datasheet(71/169 Pages) SEMTECH

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GS3470

Final Data Sheet

Rev.8

PDS-060500

September 2017

71 of 169

Semtech

www.semtech.com

Figure 4-39: Ancillary Data Extraction - Step D

Toggling the ANC_DATA_SWITCH bit LOW returns the process to step A (Figure 4-39).

Note 1: Toggling the ANC_DATA_SWITCH must occur at a time when no extraction is

taking place, i.e. when the both the Y/1ANC and C/2ANC signals are LOW.

To turn extraction off, the ANC_DATA_EXT_MASK bit must be set HIGH.

In HD mode, the device can detect ancillary data packets in the Luma video data only,

Chroma video data only, or both. By default (at power-up or after a system reset) the

device extracts ancillary data packets from the Luma channel only.

In 3G mode Level A, the device can detect ancillary data packets in Luma video (Data

Stream 1) only, Chroma video (Data Stream 2) only, or both. By default (at power-up or

after a system reset) the device extracts ancillary data packets from Data Stream 1 only.

In 3G mode Level B, the device can detect ancillary data packets in Luma video only,

Chroma video only, or both from either Link A or Link B. Selection of Link A or Link B for

ANC data extraction is done via the host interface.

In 3G Level B the device may be programmed via the user interface so that the YANC

data from Link A is extracted as the YANC data and the YANC data from Link B is

extracted as CANC data. By default, or at reset or power-up, this is the setup for 3G level

B input signals.

1023

ApplicationLayer

ReadPointer

Internal Write

Pointer

BankA

ANC_DATA_SWITCH=HIGH

1023

BankB

ANCDATA

C00

FFF

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