GS2960 Datasheet, PDF (27/97 Pages) Semtech Corporation – 3Gb/s, HD, SD SDI Receiver Complete with SMPTE Video Processing

4.2.2 Level B Mapping
The 2 x 292 HD SDI interface - this can be two distinct links running at 1.5Gb/s or one
3Gb/s link formatted according to SMPTE 292 on two 10-bit links (Y/C interleaved). For
1080p/50/59.94/60 4:2:2 video formats, each link should be line-interleaved as per
SMPTE 372M. See Figure 4-2:
multiplexed Y/C data
Data Stream 1
(”Link A”)
EAV
Data Stream 2
(”Link 2”)
HANC
SAV
Active Video
“double” TRS headers from
interleaved HD-SDI;
Figure 4-2: Level B Mapping
The GS2960 distinguishes between Level A and Level B mappings at 3Gb/s. When Level
B data is detected, each 10-bit link is demultiplexed into its individual component
streams, and most video processing features, including error detection and correction
are enabled separately for Data Stream 1 and Data Stream 2 (Link A and Link B,
respectively).
NOTE: Ancillary data extraction can only be enabled for one link for 3Gb/s Level B data.
Data Stream 1 or Data Stream 2 can be selected via the host interface.
4.3 Serial Digital Input
The GS2960 can accept serial digital inputs compliant with SMPTE 424M, SMPTE 292
and SMPTE 259M-C. The serial digital input buffer features 50Ω input termination and
can be DC-coupled to Gennum's 3Gb/s-capable equalizers.
4.4 Serial Digital Loop-Through Output
The GS2960 contains a 100Ω differential serial output buffer which can be configured to
output either a retimed or a buffered version of the serial digital input. The SDO and SDO
outputs of this buffer can interface directly to a 3Gb/s-capable, SMPTE compliant
Gennum cable driver. See 5.1 Typical Application Circuit on page 92.
When the RC_BYP pin is set HIGH, the serial digital output is the re-timed version of the
serial input.
When the RC_BYP pin is set LOW, the serial digital output is simply the buffered version
of the serial input, bypassing the internal reclocker.
The output can be disabled by setting the SDO_EN/DIS pin LOW. The output is also
disabled when the STANDBY pin is asserted HIGH. When the output is disabled, both
SDO and SDO pins are set to VDD and remain static.
GS2960 3Gb/s, HD, SD SDI Receiver Complete with
SMPTE Video Processing
Data Sheet
48003 - 6
September 2012
27 of 97