Embedded Peripherals IP User Guide

ID 683130
Date 10/24/2025
Public
Document Table of Contents
1. Introduction 2. Avalon® -ST Serial Peripheral Interface Core 3. SPI Core 4. SPI Agent/JTAG to Avalon® Host Bridge Cores 5. Intel eSPI Agent Core 6. eSPI to LPC Bridge Core 7. Ethernet MDIO Core 8. Intel FPGA 16550 Compatible UART Core 9. UART Core 10. Lightweight UART Core 11. JTAG UART Core 12. Intel FPGA Avalon® Mailbox Core 13. Intel FPGA Avalon® Mutex Core 14. Intel FPGA Avalon® I2C (Host) Core 15. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 16. EPCS/EPCQA Serial Flash Controller Core 17. Intel FPGA Serial Flash Controller Core 18. Intel FPGA Serial Flash Controller II Core 19. Intel FPGA Generic QUAD SPI Controller Core 20. Intel FPGA Generic QUAD SPI Controller II Core 21. Interval Timer Core 22. Intel FPGA Avalon FIFO Memory Core 23. On-Chip Memory (RAM and ROM) Intel FPGA IP 24. On-Chip Memory II (RAM or ROM) Intel FPGA IP 25. PIO Core 26. PLL Cores 27. DMA Controller Core 28. Modular Scatter-Gather DMA Core 29. Scatter-Gather DMA Controller Core 30. Video Sync Generator and Pixel Converter Cores 31. Intel FPGA Interrupt Latency Counter Core 32. Performance Counter Unit Core 33. Vectored Interrupt Controller Core 34. System ID Peripheral Core 35. Intel FPGA GMII to RGMII Converter Core 36. HPS GMII to RGMII Adapter IP 37. Intel FPGA MII to RMII Converter Core 38. HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core IP 39. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 40. Intel FPGA MSI to GIC Generator Core 41. Cache Coherency Translator IP 42. Altera ACE5-Lite Cache Coherency Translator

32.1. Core Overview

The performance counter core with Avalon® interface enables relatively unobtrusive, real-time profiling of software programs. With the performance counter, you can accurately measure execution time taken by multiple sections of code. You need only add a single instruction at the beginning and end of each section to be measured.

The main benefit of using the performance counter core is the accuracy of the profiling results. Alternatives include the following approaches:

  • GNU profiler, gprofgprof 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 the Profiling Nios II Systems section in the Embedded Design Handbook.

    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.