Curtiss-Wright FHA5-XE1MWB04-00, User Manual

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APPENDIX B
8-5
SL240 XMC User Guide Copyright 2017
8.3 Frames
There are four basic frame types defined in VITA 17.1 – an IDLE frame, data frame, a SYNC
without data frame, and a SYNC with data frame. The data is divided into frames so the FPDP
signals are sampled at some minimum interval, and so the receiver is guaranteed to see IDLEs to
maintain synchronization. SYNC is used to delimit data streams and maintain host program
synchronization. This signal is under user control for PCI-based products, and is the same as the
FPDP /SYNC signal for CMC/FPDP based products. Whenever a SYNC appears on the output
of the Transmit FIFO, the current frame is terminated and the proper SYNC frame (SYNC with
data or SYNC without data) is sent. Figure B-1 shows the four types of frames and the ordered
set placement within those frames.
Figure B-1 VITA 17.1 Framing Protocol