Performance Counters - 1.0 English

Performance AXI Traffic Generator LogiCORE IP Product Guide (PG381)

Document ID
PG381
Release Date
2023-10-18
Version
1.0 English
AXI4
Request and Response Counters
Request and response counters are used to calculate the bandwidth.

Write transactions:

  • awreq_cntr: Number of Write requests issued by the TG
  • wrbeat_cntr: Number of Write beats issued by the TG
  • wlast_cntr: Number of wlast issued by the TG
  • bresp_cntr: Number of Write responses received by the TG
  • bresp_exokay_cntr: Number of Write responses received by the TG with EXOKAY response
  • bresp_slverr_cntr: Number of Write responses received by the TG with SLVERR response
  • bresp_decerr_cntr: Number of Write responses received by the TG with DECERR response
  • wbw_eff_clk_cntr : Number of cycles from the start of the TG to the wrch_done. Write Bandwidth = wrbeat_cntr/ wbw_eff_clk_cntr
Read transactions:
  • arreq_cntr: Number of Read requests issued by the TG
  • rbeat_cntr: Number of Read beats received by the TG
  • rlast_cntr: Number of rlasts received by the TG
  • rbw_eff_clk_cntr : Number of cycles from the start of the TG to the rdch_done. Read Bandwidth = rbeat_cntr / rbw_eff_clk_cntr
Latency

As part of performance monitoring, latency calculation logic is also added in the TG separately for in-order (transactions with constant ID) traffic and out-of-order (transactions with incremental ID) traffic. You must select the kind of traffic (in-order or out-of-order) that is run to calculate the latency.

For the Write channel, the latency is calculated from the start of the first request (awvalid during awready) to the reception of the first response (bvalid during bready).

For the Read channel, latency is calculated from the start of the first request (arvalid during arready) to the reception of the first response (rvalid during rready).

The best, worst, and average values for both Write and Read instructions are stored in the register set. For the average latency value, the TG sums up the latency values of all transactions.
AXI4-Stream
Bandwidth = BEAT_COUNTER/ BANDWIDTH_COUNTER.