In accordance with another embodiment of the present invention, a method for symmetrical weight updating of capacitor based resistive processing unit is described. The method includes storing a charge corresponding to a weight value with a first capacitor. The charge stored in the first capacitor is read with a readout circuit to apply a weight to an input value corresponding to an input signal using the weight value to produce an output. The weight value stored in the first capacitor is updated with an update circuit, including transferring an amount of charge from a second capacitor to the first capacitor according to an error of the output by changing a voltage difference across the first capacitor by a voltage change corresponding to the amount of charge, the voltage difference corresponding to the charge stored in the first capacitor.

These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.