JAJSEY1C April 2019 – March 2022 ADC12DJ5200RF
A multiblock is a 32 block container which consists of a concatenation of 32 blocks. An extended multiblock is a concatenation of multiple multiblocks, where E defines the number of multiblocks in an extended multiblock. A frame can be split between blocks and multiblocks, but there must be an integer number of frames in an extended multiblock. An extended multiblock is only necessary when a multiblock does not have an integer number of frames. If an extended multiblock is not used, because a multiblock contains an integer number of frames, then the E parameter is equal to 1 to indicate that there is one multiblock in an extended multiblock. Values of E greater than 1 are not supported in ADC12DJ5200RF.
An extended multiblock is analogous to a multiframe in the 8B/10B transport layer. The local extended mutiblock clock (LEMC) keeps track of the start and end of a multiblock for deterministic latency and data synchronization purposes in the same way the LMFC tracks the start and end of a multiframe in 8B/10B encoding. The LEMC is reset by the SYSREF signal to a deterministic phase in both the transmitter and receiver in order to act as a timing reference for deterministic latency. The LEMC clock frequency is defined by Equation 12 where fBIT is the serialized bit rate (line rate) of the SerDes interface. The frequency of SYSREF must equal to or an integer division of fLMFC when using 64B/66B encoding modes if SYSREF is a continuous signal.