Aborting a Transmission - Aborting a Transmission - 3.0 English - PG369

Versal Adaptive SoC 600G Channelized Multirate Ethernet Subsystem (DCMAC) LogiCORE IP Product Guide (PG369)

Document ID
PG369
Release Date
2025-06-11
Version
3.0 English

A frame can be aborted on the segmented interface by asserting err alongside eop for the final segment being transferred.

The following diagram shows a frame abort, using a 100G (narrow), two segment interface for illustration.

Figure 1. AXI4-Stream Transmit Frame Abort

In the figure, frame A starts on segment 0 in cycle #2 and continues in segment 1, then segment 0 of the next cycle. An explicit frame transfer abort occurs in segment 1 of cycle #3 with err1 asserted alongside eop1.

Next, a new frame (frame B) begins in segment 0 of cycle #5 and continues beyond the edge of the diagram. It is acceptable to begin a new frame in the segment immediately following an aborted frame. There is no need for any idle bus segments. Two related restrictions, however, do exist:
  1. sop segments cannot come closer than one every four segments (there is a minimum 64-byte interval between sop signals).
  2. An eop segment cannot be in either of the two segments immediately following an sop (the minimum frame, even when aborting, must be four segments long).