In the development of new FPGA architectures, a designer must balance speed, density and routing flexibility. In this paper, we discuss a new FPGA architecture based on a patented [1], novel, segmented routing fabric that is targeted to high performance and predictability but does not sacrifice routability or area efficiency. Current segmented architectures allow much flexibility in routing, but incur large delay penalties when a signal has high fanout or must traverse medium to long distances to reach its target. Reducing the number of programmable interconnect points (PIPs) that a signal must traverse to reach its target, while eliminating the RC delay buildup due to signal fanout, improves design performance and offers highly predictable signal delays.

We present a new synthesis strategy that can automate fully the path from an analog circuit topology and performance specifications to a sized circuit schematic. This strategy relies on asymptotic waveform evaluation to predict circuit performance and simulated annealing to solve a novel unconstrained optimization formulation of the circuit synthesis problem. We have implemented this strategy in a pair of tools called ASTRX and OBLX. To show the generality of our new approach, we have used this system to resynthesize essentially all the analog synthesis benchmarks published in the past decade; ASTRX/OBLX has resynthesized circuits in an afternoon that, for some prior approaches, had required months. To show the viability of the approach on difficult circuits, we have resynthesized a recently published (and patented), high-performance operational amplifier; ASTRX/OBLX achieved performance comparable to the expert manual design. And finally, to test the limits of the approach on industrial-sized problems, we have synthesized the component cells of a pipelined A/D converter; ASTRX/OBLX successfully generated cells 2-3/spl times/ more complex than those published previously.

We describe ASTRX/OBLX, a synthesis system that can size high-performance analog circuit topologies to meet usersupplied linear performance specifications without designer-supplied equations.We present synthesis results for a large suite of circuit benchmarks and show that, when compared to prior approaches, ASTRX/OBLX can synthesize high-performance circuits with up to 3 orders of magnitude less initial design effort.