Altera SDI II MegaCore - Manual (Page 66)

3Gb Demux
This submodule demultiplex the Y link A, C link A, Y link B, and C link B from the received 20-bit data
for further processing. This submodule is mainly for 3G-SDI level B operation and it is required in 3G-
SDI and triple rate SDI modes.
If you enable the option for level B to level A conversion, the FIFO buffer within this submodule is
instantiated to transfer the received data across asynchronous clocks. This process is described in the Level
B to Level A conversion section.
Related Information
• Level B to Level A conversion on page 2-4
Extract Line
The HD-SDI includes the current video line number as part of the EAV extension words. The insert line
submodule encodes the 11-bit line number in two of these extension words as defined in the SMPTE292M
specification.
This submodule decodes the data words and registers them when the Match TRS submodule indicates
that the current words are LN0 and LN1 extension words.
Figure 4-21: Line Number Extraction
3 FF 000 000 XYZ LN0 CRC0 CRC1 LN1
LN n LN n-1
OUTPUT DATA
OUTPUT LN
Extract Payload ID
This submodule detects one 10-bit Y data stream from an interface and extracts the payload ID packet
present in that data stream. For dual link HD-SDI interfaces, you need two of these modules to look for
payload ID packets on the Y data streams of both links. For 3G/6G/12G-SDI level B operation, the insert
payload ID submodule inserts the payload ID packets as they would be in a dual link HD SDI
(SMPTE372) interface. The level B data streams must be unpacked into two HD-SDI data streams, and
you need two of these modules to extract the payload ID packets from the Y data streams of both links.
This submodule outputs a valid signal which indicates that a valid payload ID packet data is present on
the submodule's payload output port. The submodule updates this payload each time it detects an error-
free SMPTE352 packet. The submodule discards erroneous packets like checksum error and the payload
port retains the information from the last good packet. The valid output signal goes high immediately
upon receiving a good packet. If the submodule detects erroneous packets or the packets are no longer
present, the valid output signal remains high for a number of frames or fields after the last good packet is
received. This submodule provides all four bytes of the payload ID data on its payload output port.
Detect Format
This submodule monitors the line and frame timing of an incoming SDI stream. It generates various flags
to indicate whether the receive stream is locked.
4-24 3Gb Demux
UG-01125
2015.05.04
Altera Corporation SDI II IP Core Functional Description
Send Feedback