Performance Monitor FPGA IP User Guide: Agilex™ 5 and Agilex™ 7 FPGAs

ID 817760
Date 4/01/2024
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

3.1. AXI4 Traffic Limitations

The AXI4 interface has the following limitations for collecting performance metrics.
  • Not all metrics can be provided in a single run of the application.
  • Supports a maximum of 65,533 outstanding transactions for accurate latency metrics.
  • Does not support maximum or minimum latency (rather the maximum filter applied to latency metrics provides the maximum number of outstanding transactions).
  • Requires no traffic gaps on read or write channels greater than 65,535 cycles to measure efficiency accurately.
  • Requires at least 2 transactions on an AXI4 subchannel to measure efficiency for the subchannel.
  • Counters are 48 bits; variable sizes are not currently supported.
  • Does not support metric configuration mid traffic.
  • Reading metrics mid traffic provides an approximation rather than an exact value.
  • Supports a maximum of 64 monitors in the system.
  • Requires symmetry in RDATA and WDATA widths as well as ARID and AWID widths.