DS849 Datasheet, PDF (9/10 Pages) Xilinx, Inc – LogiCORE IP Spartan-6 FPGA Triple-Rate SDI v1.0

LogiCORE IP Spartan-6 FPGA Triple-Rate SDI v1.0
Operation of the Triple-Rate SDI Transmitter in SD-SDI Mode
In SD-SDI mode, the GTP transmitter is configured to run at a line rate of 2.97 Gb/s. The Triple-Rate SDI transmitter
takes in a 10-bit data stream at a 27 MHz rate, optionally calculates and inserts SMPTE RP-168 EDH packets,
scrambles the data, and then replicates each bit of the 270 Mb/s bitstream 11 times before sending the data to the
GTP transmitter. Because the line rate of the GTP transmitter is 11 times the 270 Mb/s bit rate of the SD-SDI signal
and the data provided to the GTP transmitter by the Triple-Rate SDI transmitter has each bit replicated 11 times, the
resulting bitstream output by the GTP transmitter is a valid 270 Mb/s SD-SDI bitstream.
The EDH generation and insertion function does make the Triple-Rate SDI transmitter larger. However, if this
function is not required, it can be optimized out of the design by permanently disabling EDH insertion.
The 10-bit, 27 MHz data stream supplied to the Triple-Rate SDI transmitter must be an interleaved luma/chroma
data stream and must be fully compliant with the SMPTE 259 SD-SDI requirements. Typically, this means that the
input data streams should have EAV and SAV sequences at the appropriate places. But, for SD-SDI mode only, the
transmitter has a video flywheel that generates and inserts EAV and SAV sequences if they are missing. This
flywheel only works in SD-SDI mode and only if insertion of EDH packets is enabled.
Operation of the Triple-Rate SDI Transmitter in HD-SDI Mode
In HD-SDI mode, the Triple-Rate SDI transmitter takes in two 10-bit data streams, one data stream for the luma
channel and one for the chroma channel. These data streams must be fully compliant with SMPTE 274, SMPTE 296,
or SMPTE 2048-2, as specified by the SMPTE 292 HD-SDI standard. Thus the data stream must have EAV and SAV
sequences at the appropriate places. The Triple-Rate SDI transmitter optionally inserts line numbers and calculates
and inserts CRC values into the data streams in the appropriate words immediately after the EAV sequence. The
data streams are interleaved and scrambled, and then output to the GTP transmitter for serialization.
As previously described, the Triple-Rate SDI transmitter can optionally generate and insert SMPTE 352 payload ID
packets. In the case of HD-SDI, these packets are inserted in the luma channel only on specific lines that are
dependent upon the video format. The SMPTE 352 standard requires that these packets be placed at the beginning
of the HANC space, immediately after the CRC words that follow the EAV. Following the SMPTE 352 packet,
applications might need to insert other ancillary data packets, such as embedded audio packets. It is best to allow
the Triple-Rate SDI transmitter to insert the SMPTE 352 packets first, before the application begins inserting other
packets in the HANC space, to ensure that the SMPTE 352 packets do, in fact, appear at the beginning of the HANC
space. To facilitate this, the Triple-Rate SDI transmitter provides datapaths to output the data streams after they
have passed through the SMPTE 352 insertion function. These data streams can then be processed by other
application-specific modules to insert other ancillary data packets, before going back into the Triple-Rate SDI
transmitter on another set of data stream input ports for final processing. The output data streams from the
Triple-Rate SDI transmitter after SMPTE 352 packet insertion do not yet have line numbers and CRC words inserted
by the transmitter.
Operation of the Triple-Rate SDI Transmitter in 3G-SDI Mode
In 3G-SDI mode, the Triple-Rate SDI transmitter accepts either two or four 10-bit data streams depending on the
SMPTE 425 level.
For level A, two input data streams are accepted at a nominal rate of 148.5 MHz or 148.5/1.001 MHz. These data
streams must be fully compliant with SMPTE 274, SMPTE 296, SMPTE 2048-2, SMPTE 428-9, or SMPTE 428-19 as
specified by the SMPTE 425 standard. The transmitter optionally inserts SMPTE 352 packets into both data streams
and outputs the data streams for further ancillary data packet insertion, as described in the HD-SDI section. The
transmitter optionally inserts line number words and generates and inserts CRC words into both data streams. The
data streams are interleaved and scrambled and then output to the GTP transmitter for serialization.
DS849 June 22, 2011
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Product Specification