GS2970 datasheet(73/145 Pages) SEMTECH

73 / 145 page

GS2970 3Gb/s, HD, SD SDI Receiver Complete with

SMPTE Audio and Video Processing

Data Sheet

47478 - 4

September 2012

73 of 145

programmed (with the other set to zero), ancillary data packets are extracted from one

line per frame only. When both registers are set to zero, the device extracts packets from

all lines.

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 4-29: Ancillary Data Extraction - Step A).

Figure 4-29: 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

4-30: Ancillary Data Extraction - Step B).

ANCDATA

1023

Application Layer

Read Pointer

Internal Write

Pointer

Bank A

ANC_DATA_SWITCH=LOW

1023

Bank B

800h

BFFh

GS2970 Datasheet(PDF) 73 Page - Semtech Corporation