Visible to Intel only — GUID: iga1401400276043
Ixiasoft
Visible to Intel only — GUID: iga1401400276043
Ixiasoft
37.1. Core Overview
The main benefit of using the performance counter core is the accuracy of the profiling results. Alternatives include the following approaches:
- GNU profiler, gprof—gprof provides broad low-precision timing information about the entire software system. It uses a substantial amount of RAM, and degrades the real-time performance. For many embedded applications, gprof distorts real-time behavior too much to be useful.
- Interval timer peripheral—The interval timer is less intrusive than gprof. It can provide good results for narrowly targeted sections of code.
The performance counter core is unobtrusive, requiring only a single instruction to start and stop profiling, and no RAM. It is appropriate for high-precision measurements of narrowly targeted sections of code.
For further discussion of all three profiling methods, refer to AN 391: Profiling Nios II Systems.
The core is designed for use in Avalon® -based processor systems, such as a Nios® II or Nios® V processor system. Intel FPGA device drivers enable the Nios® II or Nios® V processor to use the performance counters.