ADC sampling rate problem

Official Hardware Mega Due
1

Hello
i have a problem with my arduino Due sampling rate, when i read the ADC_MR register i get (0x10380200) so the sampling rate should (40uS) but when i run this code below i get (5uS per sample) so where is the problem here?

 t=micros();
  SensorVAL = analogRead(sensorPin); 
  act=micros()-t;
  Serial.println(SensorVAL );
  Serial.println(act);
2

See this thread, reply #6 for an example sketch:

https://forum.arduino.cc/index.php?topic=487989.0

3

thanks ard_newbie
i want to calculate the speed of analogread() function using the ADC_MR register and micros() function but i get different results