Xilinx AXI4-Stream-FIFO 使用提示

AXI4 FIFOs operate only in First-Word Fall-Through mode. The First-Word Fall-Through
(FWFT) feature provides the ability to look ahead to the next word available from the FIFO
without issuing a read operation. When data is available in the FIFO, the first word falls
through the FIFO and appears automatically on the output bus.

如下图：AXI4-Stream一定工作在FWFT模式，