Embedded Peripherals IP User Guide

ID 683130
Date 12/13/2021
Public

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Document Table of Contents
1. Introduction 2. Avalon® -ST Multi-Channel Shared Memory FIFO Core 3. Avalon® -ST Single-Clock and Dual-Clock FIFO Cores 4. Avalon® -ST Serial Peripheral Interface Core 5. SPI Core 6. SPI Agent/JTAG to Avalon® Host Bridge Cores 7. Intel eSPI Agent Core 8. eSPI to LPC Bridge Core 9. Ethernet MDIO Core 10. Intel FPGA 16550 Compatible UART Core 11. UART Core 12. JTAG UART Core 13. Intel FPGA Avalon® Mailbox Core 14. Intel FPGA Avalon® Mutex Core 15. Intel FPGA Avalon® I2C (Host) Core 16. Intel FPGA I2C Agent to Avalon® -MM Host Bridge Core 17. Intel FPGA Avalon® Compact Flash Core 18. EPCS/EPCQA Serial Flash Controller Core 19. Intel FPGA Serial Flash Controller Core 20. Intel FPGA Serial Flash Controller II Core 21. Intel FPGA Generic QUAD SPI Controller Core 22. Intel FPGA Generic QUAD SPI Controller II Core 23. Interval Timer Core 24. Intel FPGA Avalon FIFO Memory Core 25. On-Chip Memory (RAM and ROM) Intel FPGA IP 26. On-Chip Memory II (RAM or ROM) Intel FPGA IP 27. Optrex 16207 LCD Controller Core 28. PIO Core 29. PLL Cores 30. DMA Controller Core 31. Modular Scatter-Gather DMA Core 32. Scatter-Gather DMA Controller Core 33. SDRAM Controller Core 34. Tri-State SDRAM Core 35. Video Sync Generator and Pixel Converter Cores 36. Intel FPGA Interrupt Latency Counter Core 37. Performance Counter Unit Core 38. Vectored Interrupt Controller Core 39. Avalon® -ST Data Pattern Generator and Checker Cores 40. Avalon® -ST Test Pattern Generator and Checker Cores 41. System ID Peripheral Core 42. Avalon® Packets to Transactions Converter Core 43. Avalon® -ST Multiplexer and Demultiplexer Cores 44. Avalon® -ST Bytes to Packets and Packets to Bytes Converter Cores 45. Avalon® -ST Delay Core 46. Avalon® -ST Round Robin Scheduler Core 47. Avalon® -ST Splitter Core 48. Avalon® -MM DDR Memory Half Rate Bridge Core 49. Intel FPGA GMII to RGMII Converter Core 50. Intel FPGA MII to RMII Converter Core 51. Intel FPGA HPS GMII to TSE 1000BASE-X/SGMII PCS Bridge Core 52. Intel FPGA HPS EMAC to Multi-rate PHY GMII Adapter Core 53. Intel FPGA MSI to GIC Generator Core

37.5.2. Using the Performance Counter

In a Nios® II or Nios® V processor system, you can control the performance counter core with a set of highly efficient C macros, and extract the results with C functions.

Hardware Constants

API Summary

The Nios® II or Nios® V processor application program interface (API) for the performance counter core consists of functions, macros, and constants.

Table 367.  Performance Counter Macros and Functions
Name Summary
PERF_RESET() Stops and disables all counters, resetting them to 0.
PERF_START_MEASURING() Starts the global counter and enables section counters.
PERF_STOP_MEASURING() Stops the global counter and disables section counters.
PERF_BEGIN() Starts timing a code section.
PERF_END() Stops timing a code section.
perf_print_formatted_report() Sends a formatted summary of the profiling results to stdout.
perf_get_total_time() Returns the aggregate global profiling time in clock cycles.
perf_get_section_time() Returns the aggregate time for one section in clock cycles.
perf_get_num_starts() Returns the number of counter events.
alt_get_cpu_freq() Returns the CPU frequency in Hz.

For a complete description of each macro and function, see the Performance counter API section.

You can get the performance counter hardware parameters from constants defined in system.h. The constant names are based on the performance counter instance name, specified on the System Contents tab in Platform Designer.

Table 368.  Performance Counter Constants
Name (1) Meaning
PERFORMANCE_COUNTER_BASE Base address of core
PERFORMANCE_COUNTER_SPAN Number of hardware registers
PERFORMANCE_COUNTER_HOW_MANY_SECTIONS Number of section counters
Note :
  1. Example based on instance name performance_counter.

Startup

Before using the performance counter core, invoke PERF_RESET to stop, disable and zero all counters.

Global Counter Usage

Use the global counter to enable and disable the entire performance counter core. For example, you might choose to leave profiling disabled until your software has completed its initialization.

Section Counter Usage

To measure a section in your code, surround it with the macros PERF_BEGIN() and PERF_END(). These macros consist of a single write to the performance counter core.

You can simultaneously measure as many code sections as you like, up to the number specified in Platform Designer. See the Define Counters section for details. You can start and stop counters individually, or as a group.

Typically, you assign one counter to each section of code you intend to profile. However, in some situations you may wish to group several sections of code in a single section counter. As an example, to measure general interrupt overhead, you can measure all interrupt service routines (ISRs) with one counter.

To avoid confusion, assign a mnemonic symbol for each section number.

Viewing Counter Values

Library routines allow you to retrieve and analyze the results. Use perf_print_formatted_report() to list the results to stdout , as shown below.

Table 369.  Example 1:

perf_print_formatted_report(
     (void *)PERFORMANCE_COUNTER_BASE, // Peripheral's HW base address
     alt_get_cpu_freq(),               // defined in "system.h"
     3,                                // How many sections to print
     "1st checksum_test",              // Display-names of sections
     "pc_overhead",

     "ts_overhead");

The example below creates a table similar to this result.

Table 370.  Example 2:

--Performance Counter Report--

Total Time: 2.07711 seconds (103855534 clock-cycles)

+-----------------+--------+-----------+---------------+-----------+

| Section         |    %   | Time (sec)| Time (clocks) |Occurrences|

+-----------------+--------+-----------+---------------+-----------+

|1st checksum_test|     50 |   1.03800 |      51899750 |         1 |

+-----------------+--------+-----------+---------------+-----------+

| pc_overhead     |1.73e-05|   0.00000 |            18 |         1 |

+-----------------+--------+-----------+---------------+-----------+

| ts_overhead     |4.24e-05|   0.00000 |            44 |         1 |

+-----------------+--------+-----------+---------------+-----------+

For full documentation of perf_print_formatted_report(), see the Performance and Counter API section.