Ultra-low power adaptively reconfigurable system

Implementations disclosed describe a programmable analog subsystem (PASS) having a plurality of reconfigurable analog circuits. The PASS may be coupled to an input/output device to receive an input signal and to an interface to communicate data with a central processing unit. In a first PASS configuration, with the plurality of reconfigurable analog circuits having a first configuration setting, the PASS may process the input signal through the plurality of reconfigurable analog circuits to generate a first output value based on the input signal. Responsive to the first output value, the PASS may reconfigure the plurality of reconfigurable analog circuits into a second PASS configuration having a second configuration setting, such that the second configuration setting is different than the first configuration setting.