The aborted transfer of a packet on the client interface is called an underrun. This can happen if a FIFO in the AXI Transmit client interface empties before a frame is completed.
This is indicated to the core in one of two ways:
- An explicit error in which a frame transfer is aborted by
deasserting
tx_axis_tuserHigh whiletx_axis_tlastis High, see AXI4-Stream Interface. - An implicit underrun in which a frame transfer is aborted by
deasserting
tx_axis_tvalidwithout assertingtx_axis_tlast.