Mapping to AXI4-Lite Interfaces - 2025.2 English - UG1483

Vitis Model Composer User Guide (UG1483)

Document ID
UG1483
Release Date
2025-11-20
Version
2025.2 English

Gateway Ins and Gateway Out blocks tagged as AXI4-Lite registers map to different 32-bit registers within a Memory Map, as shown in following Schematic.

The schematic below is an example of mapping to a single AXI4-Lite interface, assuming all gateways have the same interface name. In a schematic with multiple AXI4-Lite interfaces, each group of gateways with the same interface name maps to a separate AXI4-Lite interface.

Figure 1. Single AXI4-Lite Interface

As shown in the preceding diagram, module example_dds_inf_axi_lite_interface is inserted into the design RTL. This drives the config_tvalid and config_tdata ports of the Model Composer design. At the top level, the tool exposes a slave AXI4-Lite Interface. Address decoding occurs within this module. The config_tvalid and config_tdata ports are driven based on the address obtained from the processor.

The number of AXI4-Lite interface registers and the offset specifications of each AXI4-Lite register determines the number of bits required for addressing (s_axi_araddr and s_axi_awaddr). Module generation provides enough bits to uniquely decode each register. In this example, there are two Gateways – phase_data and phase_valid. Each port is assigned an address offset of 0x0000 & 0x0004. Hence three address bits are allocated.