Synthesis of mixed-signal designs from behavioral specifications must address analog-digital partitioning. In other words, determining what portions of the design are best implemented using analog and digital circuitry. In this work, we target reconfigurable mixed-signal systems composed of field-programmable analog and digital arrays. These field-programmable systems are invaluable for rapid hardware prototyping and evaluation. We begin with system behavior specified using a signal-/data-flow graph representation. This is partitioned into analog and digital domains, and then mapped onto the target mixed-signal hardware. The solution must satisfy constraints on imposed by the target mixed-signal architecture on available configurable resources, available data-converters, their resolution and speed, and I/O pins. The quality of the solution is evaluated based two metrics, namely feasibility and performance cost. The former is a measure of the validity of the solution with respect to the constraints. The latter measures the performance of the system based on area, bandwidth and noise.