Neural network circuits having non-volatile synapse arrays

A non-volatile neural network, comprising:

• a first neural array layer including a first plurality of neurons;
• a second neural array layer including a second plurality of neurons;
• and
• a synapse array layer disposed between the first and second neural array layers and including a plurality of non-volatile synapses,
• wherein each non-volatile synapse in the synapse array layer is electrically coupled to a neuron of the first plurality of neurons and to one or more neurons of the second plurality of neurons, and wherein each non-volatile synapse includes:
• a first input signal line for receiving a first input signal from a neuron in the first plurality of neurons;
• a reference signal line for providing a reference signal;
• first and second output lines for carrying first and second output signals therethrough, the first and second output signals being processed and transmitted to one or more neurons of the second plurality of neurons;
• and
• first and second cells for generating the first and second output signals, respectively, each of the first and second cells including:
• a first upper select transistor having a gate that is electrically coupled to the first input signal line;
• and
• a first resistive changing element having one end connected to the first upper select transistor in series and an other end electrically coupled to the reference signal line, a value of the first resistive changing element being programmable to change a magnitude of an output signal,
• wherein a drain of the first upper select transistor of the first cell is electrically coupled to the first output line and a drain of the first upper select transistor of the second cell is electrically coupled to the second output line.