JAJSEY1C April 2019 – March 2022 ADC12DJ5200RF
After the transmitter detects the SYNC signal deassert (logic '0' to logic '1' transition), the transmitter waits until its next LMFC edge to start sending the initial lane alignment sequence (ILAS). The ILAS consists of four multiframes each containing a predetermined sequence. The receiver searches for the start of the ILAS to determine the frame and multiframe boundaries. Each multiframe of the ILAS starts with a /R/ character (K28.0) and ends with a /A/ character (K28.3) and either can be used to detect the boundary of a multiframe. Each lane starts buffering its data in the elastic buffer once the ILAS reaches the receiver, starting with the /R/ character, until all receivers have received the ILAS and subsequently release the ILAS from all lanes at the same time in order to align the lanes. The elastic buffer release point is chosen to avoid ambiguity in the release of the data caused by variation in the data delay (arrival of the ILAS at the receiver for each lane). The second multiframe of the ILAS contains configuration parameters for the JESD204C link configuration that can be used by the receiver to verify that the transmitter and receiver configurations match.