The Top Level Settings Tab is shown in the following figure.
Figure 1. Top Level Settings Tab
- Packet Data Bus Width
- AXI-Stream Packet Data Bus Width: can be set to 32-bit, 64-bit, 128-bit, 256-bit, 512-bit, or 1024-bit.
- Packet Rate
- Packet rate in million packets/second. This parameter is relevant to any CAM tables that might be in the user's P4 program. A lower packet rate can result in a lower resource utilization for the CAMs. Vitis Networking P4 applies back-pressure on the s_axis interface if necessary to avoid exceeding the packet rate at the CAMs.
- Enable Packet Rate Limiter
- This enables a packet rate limiter at the input of Vitis Networking P4 to strictly prevent input streams from exceeding the specified packet rate. Vitis Networking P4 applies back-pressure on the s_axis interface if necessary, following a tlast word, to ensure that the next Start-Of-Packet does not occur too soon and violate the specified packet rate. For more information on the Packet Rate Limiter, see s_axis Interface.
- P4 File
- Browse to select a P4 file then click OK. The Vitis Networking P4 IP invokes the P4C-VitisNetP4 compiler, automatically compiling the P4 file once it is selected, and unlocks the other four tabs.
- P4 Compile
- Re-compiles the P4 for use when the selected P4 file has been edited by the user.
- Calculate Latency
- Calculates the total latency of the Vitis Networking P4 system. This button appears, for convenience, on each tab. See Latency for additional information on the latency calculation.