A learning method of a semiconductor device of the present invention
comprises a neuro device having a multiplier as a synapse in which a
weight varies according to an input weight voltage, and functioning as a
neural network system that processes analog data, comprising a step A of
inputting predetermined input data to the neuro device and calculating an
error between a target value of an output of the neuro device with respect
to the input data and an actual output, a step B of calculating variation
amount in the error by varying a weight of the multiplier thereafter, and
a step C of varying the weight of the multiplier based on the variation
amount in the error, wherein in the steps B and C, after inputting a reset
voltage for setting the weight to a substantially constant value to the
multiplier as the weight voltage, the weight is varied by inputting the
weight voltage corresponding to the weight to be varied.
