The purpose of the segmented AXI4-Stream bus is to provide a means to optimally use the data bus. Therefore, ideally segments
should be filled in sequence with no gaps between used segments. A “gap” on the TX
AXI4-Stream bus is a disabled segment (that is,
tx_axis_tuser_ena<M>=0).
All segments of the bus can be IDLE, or one or more segments (potentially to the last segment of the bus) can be disabled under the following conditions:
- After a segment that results in a burst of size BurstMax
- After a segment containing EOP
- After a non-EOP segment that results in a burst of size < BurstMax (and > 64B)
The transmit logic of the ILKNF subsystem never violates the BurstShort value specified by c0_ctl_tx_burstshort register field of the CFG_C0_TX_MAIN_REG register.
However, the core might inject more than the absolute minimum required number of IDLE
Control Words depending on the burst size and on which segment the burst ends.