User guide

3–10 Chapter 3: Interfaces
Avalon-ST Video Protocol
Video and Image Processing Suite January 2013 Altera Corporation
User Guide
Figure 3–8 to Figure 3–10 show examples of control data packets, and how they are
split into symbols.
Ancillary Data Packets
Ancillary data packets send ancillary packets between MegaCore functions. Ancillary
data packets are typically placed between a control data packet and a video data
packet and contain information that describes the video data packet, for example
active format description codes.
An ancillary data packet can contain one or more ancillary packets, each ancillary
packet starts with the hexadecimal code 0, 3FF, 3FF.
f The format of ancillary packets is defined in the SMPTE S291M standard.
Figure 3–8. Three Symbols in Parallel
Figure 3–9. Two Symbols in Parallel
Figure 3–10. One Symbol in Parallel
Start End
3
15
Symbols in least significant bits
Symbols in middle significant bits
Symbols in most significant bits
Control data, reference numbers to Table 4-5
X
Control data packet type identifier
(4 bits in least significant symbol,
X’s for unused symbols)
X
96
852
741
Control data packet type identifier
(4 bits in least significant symbol,
X’s for unused symbols)
Symbols in least significant bits
Symbols in most significant bits
Start End
Control data, reference numbers to Table 4-5
3
15
XX
9
68
5
2
7
4
1
Control data, reference numbers to Table 4-5
Control data packet type identifier
(4 bits in least significant symbol,
X’s for unused symbols)
Start End
315 96852741