Curtiss-Wright FHF5-PC4MWB04-00, Hardware Reference Manual

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FPDP PRIMER
Copyright 2017 9-5 FibreXtreme Hardware Reference
When fixed or dynamic size repeating frame data is transmitted onto the FPDP
bus, the FPDP-TM must assert a /SYNC pulse while /DVALID is already
asserted. The /SYNC pulse must be asserted at the same time as the last data item
of every frame. The FPDP-RM and FPDP-R devices must recognize that the
current data is the last data item in current frame when both /SYNC and /DVALID
are asserted. Since /SYNC is asserted at the end of a frame, the first data frame
transmitted will not be synchronized. As a result, the system designer may wish to
discard this first unsynchronized data frame. All data frames are the same size
when fixed size repeating frame data is transmitted.
DYNAMIC SIZE REPEATING FRAME DATA
 Synchronization must occur prior to data to which it applies.
 Synchronization occurs at the same time the last data word in the block
before is transferred.
 /SYNC must be asserted at the end of the data block while /DVALID is still
asserted.
 Because synchronization occurs at the end of the data block, the first data
block will not be synchronized.
 Synchronization occurs frequently.
 Data frames may vary in size.
For dynamic size repeating frame data, the behavior of the /SYNC pulse is the same as for
fixed size repeating frame data, with the exception of varying sized frames.
9.4
Serial FPDP Theory of Operation
The protocol and framing for Serial FPDP are listed in Appendix C. Serial FPDP operates
similar to parallel FPDP with respect to maintaining data framing with the SYNC signal,
but the SYNC signal does not correlate with data frames on the fiber. Any form of data
framing listed in section 9.3.2 can be mapped to Serial FPDP, since the data stream and
SYNCs are maintained. However, the timing may not be exactly the same as the parallel
FPDP version due to link framing overhead and the fact that the link operates
asynchronously to the parallel FPDP frequencies.