There are different operating modes for the ADC that can be selected. The first mode is Single-Cycle Scan Mode. In this mode all of the enabled channels are converted once. Once the selected pins have been converted once, the ADC stops. If the ADC interrupts are enabled then an interrupt will fire at this time. The second mode is called Continuous Scan Mode. It is similar to Single-Cycle Scan Mode except that instead of stopping after cycling through the enabled input channels once, it goes through the entire process again starting with the first channel. This process is continued until the ADC is told to stop. If interrupts are enabled for the ADC an interrupt is generated every time the conversion for the last input pin has finished.