Rothko: A three dimensional FPGA architecture, its fabrication, and design tools

We are designing and plan to fabricate a 3-dimensional field programmable gate array. The three dimensional technology, developed at Northeastern University, is based on transferred circuits with interconnections between layers of active devices. Interconnections are in metal, and can be placed anywhere on the chip. Our FPGA architecture, called Rothko, extends the Routing and Logic Block (RLB) model developed for the Triptych architecture [1]. This model is similar to a sea-of-gates model where individual cells can be used for routing or logic. We extend this to three dimensions by adding connections to each RLB from above and below. This makes our architecture truly 3-D with each logic block having connections to logic blocks on other layers. In this paper we present the architecture of a two layer RLB, discuss the 3-D technology we use, and discuss CAD tools for mapping designs onto Rothko.