GS2961 Datasheet, PDF (73/104 Pages) Gennum Corporation – 3Gb/s, HD, SD SDI Receiver, with Integrated Adaptive Cable Equalizer complete with SMPTE Video Processing

To start Ancillary Data Extraction, the ANC_DATA_EXT_MASK bit of the host interface
must be set LOW. Ancillary data packet extraction begins in the following frame (see
Figure 4-30: Ancillary Data Extraction - Step A).
Application Layer
Read Pointer
Internal Write
Pointer
Bank A
0 ANCDATA
ANC DATA
ANC DATA
ANC DATA
ANC DATA
ANC DATA
ANC DATA
800h
Bank B
0
800h
1023
BFFh
1023
BFFh
ANC_DATA_SWITCH = LOW
Figure 4-30: Ancillary Data Extraction - Step A
Ancillary data is written into Bank A until full. The Y/1ANC and C/2ANC output flags
can be used to determine the length of the ancillary data extracted and when to begin
reading the extracted data from memory.
While the ANC_DATA_EXT_MASK bit is set LOW, the ANC_DATA_SWITCH bit can be
set HIGH during or after reading the extracted data. New data is then written into Bank
B (up to 1024 x 16-bit words), at the corresponding host interface addresses (see Figure
4-31: Ancillary Data Extraction - Step B).
GS2961 3Gb/s, HD, SD SDI Receiver, with Integrated
Adaptive Cable Equalizer
Data Sheet
48004 - 2
November 2009
73 of 104