AMBA AXI4 (Advanced eXtensible Interface 4) is the fourth generation of the AMBA interface defined and controlled by Arm® , and has been adopted by Xilinx as the next-generation interconnect for FPGA designs. Xilinx and Arm worked closely to ensure that the AXI4 specification addresses the needs of FPGAs.
AXI is an open interface standard that is widely used by many 3rd-party IP vendors since it is public, royalty-free and an industry standard.
The AMBA AXI4 interface connections are point-to-point and come in three different flavors: AXI4, AXI4-Lite Slave, and AXI4-Stream.
- AXI4 is a memory-mapped interface which support burst transactions
- AXI4-Lite Slave is a lightweight version of AXI4 and has a non-bursting interface
- AXI4-Stream is a high-performance streaming interface for unidirectional data transfers (from master to slave) with reduced signaling requirements (compared to AXI4). AXI4-Stream supports multiple channels of data on the same set of wires.
In the following documentation, AXI4 refers to the AXI4 memory map interface, and AXI4-Lite Slave and AXI4-Stream each refer to their respective flavor of the AMBA AXI4 interface. When referring to the collection of interfaces, the term AMBA AXI4 shall be used.
The purpose of this section is to provide an introduction to AMBA AXI4 and to draw attention to AMBA AXI4 details with respect to Model Composer. For more detailed information on the AMBA AXI4 specification please refer to the Xilinx AMBA-AXI4 documents found on the AMBA AXI4 Interface Protocol page on the Xilinx website.