Event Statistics

This example project shows how to use start/stop events with the Event Recorder.

The start/stop events allow to measure execution times with different slots (0 - 15) in four different groups (A - D). The call to 'EventStart' starts a timer slot; the call to 'EventStop' stops the related timer. A call to EventStop with slot 15 stops the timers of all slots in the specific group.

This demo application does some time consuming calculations that are recorded. It runs in simulation and does not require any hardware to be present.

main.c File

#include "RTE_Components.h"             // Component selection
#include CMSIS_device_header            // defined in the RTE_Components.h file
 
#include "EventRecorder.h"
 
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
 
#define TABLE_SIZE 1000
float sin_table[TABLE_SIZE];
 
// Calculate table with sine values
void CalcSinTable (void)  {
  unsigned int i, max_i;
  float f = 0.0;
 
  max_i = TABLE_SIZE - (rand () % 500);
  EventStartAv (15, max_i, 0);                  // Start group A, slot 15, passing the max_i variable
  for (i = 0; i < max_i; i++)  {
    if (i == 200)  {
       EventStartAv (0, max_i, 0);              // Start group A, slot 0, passing the max_i variable
    }
 
    sin_table[i] = sinf(f);
    f = f + (3.141592 / TABLE_SIZE);
 
    if (i == 800)  {                            // Measure 800 table entries
      EventStopA (0);                           // Stop group A, slot 0
    }
  }
 
   EventStopA (15);                              // Stop group A, slot 15 (stops also slots 0..14)
}
 
// Return number of sqrt operations to exceed sum
unsigned int FindSqrtSum (float max_sum)  {
  unsigned int i;
  float sqrt_sum;
 
  sqrt_sum = 0.0;
  for (i = 0; i < 10000; i++) {
    sqrt_sum += sqrtf((float) i);
    if (sqrt_sum > max_sum)  {
      return (i);
    }
  }
  return (i);
}
 
unsigned int j, num, MaxSqrtSum;
 
 
int main (void) {
 
  SystemCoreClockUpdate();                      // System Initialization
 
  EventRecorderInitialize (EventRecordAll, 1U); // Initialize and start Event Recorder
  EventRecorderClockUpdate();
  EventStartC (0);                              // start measurement event group C, slot 0
  printf ("Started\n");
  for (j = 0; j < 10000; j++)  {
    CalcSinTable ();                            // calculate table with sinus values
 
    EventStartB(0);                             // start group B, slot 0
    MaxSqrtSum = rand () / 65536;               // limit for sqrt calculation
    num = FindSqrtSum ((float) MaxSqrtSum);     // return number of sqrt operations
    EventStopBv(0, MaxSqrtSum, num);            // stop group B, slot 0, output values: MaxSqrtSum, num
  }
 
  EventStopC(0);                                // stop measurement event group C, slot 0
 
  while (1) {
    __NOP();
  }
}

Build and run

This example project does not require an IDE and can be built using the CMSIS-Toolbox.

Clone this repository or download it as a ZIP file onto your computer. Follow the instructions in the README.md file to build and run the project. Use the eventlist application to analyze the outcomes.