Circuits and methods for routing crossbars with programmable vias

An integrated circuit comprising:

• first and second routing crossbars;
• and
• a third routing crossbar comprising first conductors routed in a first direction in a first conductive layer of the integrated circuit and second conductors routed in a second direction that is perpendicular to the first direction in a second conductive layer of the integrated circuit, wherein the third routing crossbar further comprises vias between the first and the second conductive layers, wherein a first subset of the vias couples a first subset of the first conductors to a second subset of the first conductors through a first subset of the second conductors,
• wherein a second subset of the vias couples the second subset of the first conductors to a second subset of the second conductors, wherein a third subset of the vias decouples the second subset of the first conductors from a third subset of the first conductors, wherein the second subset of the second conductors is coupled to the second routing crossbar, and wherein the first subset of the first conductors is coupled to the first routing crossbar.

A method for fabricating a first routing crossbar in an integrated circuit, the method comprising:

• providing first conductors routed in a first direction in a first conductive layer of the integrated circuit;
• providing second conductors routed in a second direction that is perpendicular to the first direction in a second conductive layer of the integrated circuit;
• coupling a first subset of the first conductors to a second routing crossbar;
• programming first vias to couple the first subset of the first conductors to a second subset of the first conductors through a first subset of the second conductors;
• programming second vias to couple the second subset of the first conductors to a second subset of the second conductors;
• and
• programming third vias to decouple the second subset of the first conductors from a third subset of the first conductors that are coupled to a third routing crossbar.