Here is the block diagram of the AD converter found on RL78 devices. On the left side is the configuration register for the input pins. This “ADPC” configuration register selects whether a pin is used as an analog input for the AD converter or as a digital input. The input channel is selected by using this selector together with the ADS “input channel specification” register, and the selected input channel is then fed into the sample-and-hold circuit. Not only can users select external signals but also internal ones; from the temperature sensor or the internal reference voltage for example. Then at the bottom are the AD converter mode control registers “ADM0, ADM1 and ADM2”, connected to the internal bus. These control registers switch the AD converters on or off, select the conversion time, which trigger should be used, if a wake up from Snooze Mode should be done, etc.