SBASAQ9 October 2023 ADC12QJ1600-SEP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The frames from the transport layer are combined into multiframes which are used in the process of achieving deterministic latency in subclass 1 implementations. The length of a multiframe is set by the K parameter which defines the number of frames in a multiframe. JESD204C increases the maximum allowed number of frames per multiframe (K) from 32 in JESD204B to 256 in JESD204C to allow a longer multiframe to ease deterministic latency requirements. The total allowed range of K is defined by the inequality ceil(17/F) ≤ K ≤ min(256, floor(1024/F)) where ceil() and floor() are the ceiling and floor function, respectively. The local multiframe clock (LMFC) keeps track of the start and end of a multiframe for deterministic latency and data synchronization purposes. The LMFC 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 LMFC clock frequency is given in Equation 8 where fBIT is the serialized bit rate (line rate) of the SerDes interface and F and K are as defined above. The frequency of SYSREF must equal to or an integer division of fLMFC when using 8B/10B encoding modes if SYSREF is a continuous signal.