This mode is enabled when bits SEQ3 to SEQ0 in control register 41h are set to 0011 (see Table 3-9, page 39 ). In this mode, you must select the channel for analog-to-digital conversion by writing to bit locations CH4 to CH0 in control register 40h . Various configurations for single channel mode, such as analog input mode (B U ) and settling time (ACQ), must also be set by writing to control register 40h . In applications where many channels need to be monitored, there can be a significant overhead for the microprocessor or other controller. To automate this task, a function called the automatic channel sequencer is provided.