GS2972 Datasheet, PDF (65/125 Pages) Semtech Corporation – 3G/HD/SD-SDI Serializer with Complete SMPTE Audio & Video Support

4.8 ANC Data Insertion
Horizontal or vertical ancillary data words may be inserted on up to four different lines
per video frame.
Up to 512 data words may be inserted per frame with all Data Words - including the ANC
packet ADF, DBN, DCNT, DID, SDID and CSUM words - being provided by the user via
host interface configuration.
The CSUM word is re-calculated and inserted by the ANC Data Checksum Calculation
and Insertion function.
Note that any value may be used for the CSUM word, provided that it is outside the
protected ranges from 000h to 003h and from 3FCh to 3FFh. If a CSUM value in either of
these ranges is used, it will not be corrected by the device.
The GS2972 does not provide error checking or correction to the ANC data provided by
user via the host interface. It is the responsibility of the user to ensure that all data
provided for insertion is fully standard compliant.
In 3G Level A mode, ancillary data packets are inserted into Data Stream One or Data
Stream Two as selected by the host interface. The default insertion will be in Data Stream
One. See address 02Dh, STREAM_TYPE1_LINE_X.
In 3G Level B mode, ancillary data packets are inserted into the Y or C video stream of
Link A or Link B as selected by the user in the host interface. The default insertion will
be in the Y video stream of Link A. For Link A or Link B, see Register 02Dh. For Y or C, see
Registers 026h, 028h, 02Ah and 02Ch.
In HD mode, ANC data packets are inserted into the Y or C video stream, as selected via
the host interface. The default insertion will be in the Y stream. For Y or C, see Registers
026h, 028h, 02Ah and 02Ch.
In SD mode, the ANC data packets are inserted into the multiplexed CbYCr data stream.
ANC data insertion only takes place if the IOPROC_EN/DIS pin is HIGH and
SMPTE_BYPASS is HIGH.
In addition to this, the GS2972 requires the ANC_INS bit to be set LOW in the IOPROC
register.
The ANC_PACKET_BANK register (040h - 13Fh) is used to program the ANC data words
for ANC data insertion.
4.8.1 ANC Insertion Operating Modes
User selection of one of the two operating modes is provided through host interface
configuration, using the ANC_INS_MODE register bit (see Table 4-34: Video Core
Configuration and Status Registers).
The supported operating modes are Concatenated mode and Separate Line operating
mode.
By default (at power up or after system reset), the Separate Line operating mode is
enabled.
Ancillary data packets are programmed into the ANC_PACKET_BANK host register at
addresses 040h to 13Fh.
GS2972 3G/HD/SD-SDI Serializer with Complete
SMPTE Audio & Video Support
Final Data Sheet Rev. 9
GENDOC-047479 September 2013
www.semtech.com
65 of 125