Designing via-configurable logic blocks for regular fabric

In this paper, we describe the design process of a via-configurable logic block for regular fabric. The block consists of a via-configurable functional cell and two via-configurable inverter arrays. A via-configurable functional cell can efficiently implement most commonly used CMOS static cells, and a via-configurable inverter array is efficient in implementing inverters, repeaters, and some pass-transistor logic. The cells have prefabricated transistors, contacts, and M1 wires. The M2 mask is fixed. All of the functions can be realized by customizing only an M1-M2 via mask. We construct a general-purpose fabric based on the via-configurable block and show its great flexibility in implementing a variety of functions. Compared to other fabrics based on look-up tables or programmable logic arrays, our fabric has much higher performance, smaller area, and lower power consumption.