Now to the AD converter‘s different operating modes. First are the different conversion modes; one shot conversion mode and sequential conversion mode. In one shot conversion mode an interrupt is generated and the AD converter is stopped after each conversion. In sequential conversion mode, a trigger starts the AD converter and an interrupt is generated after the first valid result. However, the process doesn’t stop after the first conversion, it instead continues and generates an interrupt after each new conversion is finished. In this case the AD converter can be stopped by software, stopping the conversion immediately. Next to look at channel selection - again there are two different modes possible; one is select mode and the second is scan mode. In select mode the same channel is always selected, so the input selector does not switch to another channel. If this is combined with sequential conversion mode, one will always get the result of the same channel, or alternatively always have a value available for the selected channel. Finally, the last mode is scan mode; this is different than select mode in that the input selector is automatically switched over from one channel to the next. For example in scan mode starting with channel zero; the first AD conversion is done for channel zero and the result is stored in the result register, then the input is switched to channel one and the next conversion done and so on.