BurstShort in ILKNF is set
to 64 bytes by the programming of the
c0_ctl_tx_burstshort register field of the CFG_C0_TX_MAIN_REG
The Segmented AXI4-Stream TX core never violates the BurstShort value. However, more than the absolute minimum required number of IDLE control words can be injected depending on the burst size and which segment the burst ends in. Xilinx requires designing the transmitting scheduler so that burst sizes are always equal to BurstMax except for the last two transfers of a packet (EOP and EOP-1).
The required value of BurstShort must be matched by the link partner.