1.2. Auto Start
As soon as the device is powered on, it goes into the read state. The value on the capacitors is read and stored in registers. This implementation uses two capacitors that allow you to store four different values. One of the four LEDs used is switched on after the read operation that corresponds to the value read from the capacitors. This value or count is incremented and stored back into the capacitors, which act as non-volatile memory elements. Power down is then initiated by setting the power_dwn pin high. When power down is complete, the external RC circuit acts as a timer and activates the device. This is repeated until the desired delay is obtained (desired count is reached) and the complete effective stretching of the power-down time is achieved (four times in this case). The duty cycle of operation of the device can be controlled, resulting in a longer power-down period and thereby decreasing the overall power consumption.
Figure 2. Auto Start Operation Flowchart