Embodiments of the invention relate to a neuromorphic network for producing spike-timing dependent plasticity. The neuromorphic network includes a plurality of electronic neurons and an interconnect circuit coupled for interconnecting the plurality of electronic neurons. The interconnect circuit includes plural synaptic devices for interconnecting the electronic neurons via axon paths, dendrite paths and membrane paths. Each synaptic device includes a variable state resistor and a transistor device with a gate terminal, a source terminal and a drain terminal, wherein the drain terminal is connected in series with a first terminal of the variable state resistor. The source terminal of the transistor device is connected to an axon path, the gate terminal of the transistor device is connected to a membrane path and a second terminal of the variable state resistor is connected to a dendrite path, such that each synaptic device is coupled between a first axon path and a first dendrite path, and between a first membrane path and said first dendrite path.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method, comprising: in response to an electronic neuron spiking, sending a spiking signal from the electronic neuron to each axon driver and each dendrite driver connected to the electronic neuron in a network of electronic neurons interconnected via an interconnect circuit comprising a cross-bar array coupled to the electronic neurons; and generating a timing signal for controlling phased operation of the electronic neurons, the timing signal providing a sequence of phases, wherein neuron activity of each electronic neuron is confined to the sequence of phases. 2. The method of claim 1, wherein: the cross-bar array comprises: multiple axon paths; multiple dendrite paths; multiple membrane paths; and a plurality of synaptic devices for interconnecting the electronic neurons via the multiple axon paths, the multiple dendrite paths and the multiple membrane paths; and each membrane path is controlled based on a spiking of an electronic neuron of the electronic neurons, the electronic neuron connected to the membrane path. 3. The method of claim 2, wherein: the multiple dendrites paths are orthogonal to the multiple axon paths and the multiple membrane paths; each synaptic device is at a cross-point junction of the cross-bar array coupled between a dendrite path of the cross-bar array and an axon path of the cross-bar array, and between the dendrite path and a membrane path of the cross-bar array; each synaptic device provides spike-timing dependent plasticity based on neuron activity of the electronic neurons in a time phased fashion; and the time phased neuron activity of the electronic neurons is capable of changing a state of a variable state resistor as a function of time since a last spiking of an electronic neuron firing a spiking signal. 4. The method of claim 3, wherein: each synaptic device is programmable based on one or more programming signals transmitted via at least one of a dendrite path of the cross-bar array connected to the synaptic device, an axon path of the cross-bar array connected to the synaptic device, and a membrane path of the cross-bar array connected to the synaptic device. 5. The method of claim 4, further comprising: controlling neuron activity of each electronic neuron at any instant in time using the timing signal. 6. The method of claim 5, further comprising: for each electronic neuron: determining whether a total integrated input for the neuron exceeds a pre-determined threshold value to generate a spike; and in response to determining the total integrated input exceeds the pre-determined threshold value: initializing a time counter that keeps track of the time since the total integrated input for the neuron exceeds the pre-determined threshold value, such that the time counter begins its operation of time counting; generating a read signal on an axon path of the cross-bar array connected to the neuron, generating a bias potential on a membrane path of the cross-bar array connected to the neuron, and integrating signals received on a dendrite path of the cross-bar array connected to the neuron; during a first programming interval, generating a set pulse on the dendrite path; and during a second programming interval, generating a reset pulse on the dendrite path. 7. The method of claim 6, further comprising: for each electronic neuron: turning on a membrane path of the cross-bar array connected to the neuron in response to the neuron spiking; and generating a signal for decreasing or increasing the resistance of a variable state resistor in a synaptic device connected between the neuron and another electronic neuron of the electronic neurons. 8. The method of claim 7, further comprising: for each electronic neuron: during the first programming interval, generating an enable pulse of decreasing strength, in amplitude or probability of occurrence, on a dendrite path of the cross-bar array connected to the neuron, as a function of a value of the time counter that keeps track of the time elapsed since the total integrated input exceeds the pre-determined threshold value. 9. The method of claim 8, further comprising: for each electronic neuron: during the second programming interval, generating an enable pulse of decreasing strength, in amplitude or probability of occurrence, on a dendrite path of the cross-bar array connected to the neuron, as a function of a value of the time counter that keeps track of the time elapsed since the total integrated input exceeds the pre-determined threshold value; wherein the multiple membrane paths are selectively turned on to control current flowing out of the multiple dendrite paths; and wherein the multiple dendrite paths are selectively turned on to control current flowing into the multiple axon paths. 10. A system comprising a computer processor, a computer-readable hardware storage medium, and program code embodied with the computer-readable hardware storage medium for execution by the computer processor to implement a method comprising: in response to an electronic neuron spiking, sending a spiking signal from the electronic neuron to each axon driver and each dendrite driver connected to the electronic neuron in a network of electronic neurons interconnected via an interconnect circuit comprising a cross-bar array coupled to the electronic neurons; and generating a timing signal for controlling phased operation of the electronic neurons, the timing signal providing a sequence of phases, wherein neuron activity of each electronic neuron is confined to the sequence of phases. 11. The system of claim 10, wherein: the cross-bar array comprises: multiple axon paths; multiple dendrite paths; multiple membrane paths; and a plurality of synaptic devices for interconnecting the electronic neurons via the multiple axon paths, the multiple dendrite paths and the multiple membrane paths; and each membrane path is controlled based on a spiking of an electronic neuron of the electronic neurons, the electronic neuron connected to the membrane path. 12. The system of claim 11, wherein: the multiple dendrites paths are orthogonal to the multiple axon paths and the multiple membrane paths; each synaptic device is at a cross-point junction of the cross-bar array coupled between a dendrite path of the cross-bar array and an axon path of the cross-bar array, and between the dendrite path and a membrane path of the cross-bar array; each synaptic device provides spike-timing dependent plasticity based on neuron activity of the electronic neurons in a time phased fashion; and the time phased neuron activity of the electronic neurons is capable of changing a state of a variable state resistor as a function of time since a last spiking of an electronic neuron firing a spiking signal. 13. The system of claim 12, wherein: each synaptic device is programmable based on one or more programming signals transmitted via at least one of a dendrite path of the cross-bar array connected to the synaptic device, an axon path of the cross-bar array connected to the synaptic device, and a membrane path of the cross-bar array connected to the synaptic device. 14. The system of claim 13, the method further comprising: controlling neuron activity of each electronic neuron at any instant in time using the timing signal. 15. The system of claim 14, the method further comprising: for each electronic neuron: determining whether a total integrated input for the neuron exceeds a pre-determined threshold value to generate a spike; and in response to determining the total integrated input exceeds the pre-determined threshold value: initializing a time counter that keeps track of the time since the total integrated input for the neuron exceeds the pre-determined threshold value, such that the time counter begins its operation of time counting; generating a read signal on an axon path of the cross-bar array connected to the neuron, generating a bias potential on a membrane path of the cross-bar array connected to the neuron, and integrating signals received on a dendrite path of the cross-bar array connected to the neuron; during a first programming interval, generating a set pulse on the dendrite path; and during a second programming interval, generating a reset pulse on the dendrite path. 16. The system of claim 15, the method further comprising: for each electronic neuron: turning on a membrane path of the cross-bar array connected to the neuron in response to the neuron spiking; and generating a signal for decreasing or increasing the resistance of a variable state resistor in a synaptic device connected between the neuron and another electronic neuron of the electronic neurons. 17. The system of claim 16, the method further comprising: for each electronic neuron: during the first programming interval, generating an enable pulse of decreasing strength, in amplitude or probability of occurrence, on a dendrite path of the cross-bar array connected to the neuron, as a function of a value of the time counter that keeps track of the time elapsed since the total integrated input exceeds the pre-determined threshold value. 18. The system of claim 17, the method further comprising: for each electronic neuron: during the second programming interval, generating an enable pulse of decreasing strength, in amplitude or probability of occurrence, on a dendrite path of the cross-bar array connected to the neuron, as a function of a value of the time counter that keeps track of the time elapsed since the total integrated input exceeds the pre-determined threshold value; wherein the multiple membrane paths are selectively turned on to control current flowing out of the multiple dendrite paths; and wherein the multiple dendrite paths are selectively turned on to control current flowing into the multiple axon paths. 19. A computer program product comprising a computer-readable hardware storage device having program code embodied therewith, the program code being executable by a computer to implement a method comprising: in response to an electronic neuron spiking, sending a spiking signal from the electronic neuron to each axon driver and each dendrite driver connected to the electronic neuron in a network of electronic neurons interconnected via an interconnect circuit comprising a cross-bar array coupled to the electronic neurons; and generating a timing signal for controlling phased operation of the electronic neurons, the timing signal providing a sequence of phases, wherein neuron activity of each electronic neuron is confined to the sequence of phases. 20. The computer program product of claim 19, wherein: the cross-bar array comprises: multiple axon paths; multiple dendrite paths; multiple membrane paths; and a plurality of synaptic devices for interconnecting the electronic neurons via the multiple axon paths, the multiple dendrite paths and the multiple membrane paths; and each membrane path is controlled based on a spiking of an electronic neuron of the electronic neurons, the electronic neuron connected to the membrane path.