Stepwise decomposition in controlpath synthesis

A method is presented for the synthesis of the microarchitecture of controlpaths. This method is called stepwise decomposition. It focuses primarily on controlpaths of instruction set processors, however it is also applicable for more general Finite State Machine synthesis. Many of the current controlpath synthesis algorithms are based on a fixed microarchitecture, and an optimization of that microarchitecture. This stepwise decomposition method is able to synthesize microarchitectures in a range from a single PLA to multiple PLA/ROM configurations and optionally further down to hardwired, which makes it more flexible and better suited to a wider range of controlpaths than current synthesis methods. A sequence of decomposition steps, from coarse to detailed, is performed on the design to move it to the area of the design space where all constraints on space, floorplan and delay are satisfied. The method is currently implemented in APL.