Generation of Internal State Assignments for Large Asynchronous Sequential Machines

Several algorithms have been proposed for generating satisfactory state assignments for normal fundamental mode asynchronous sequential circuits. Programmed versions of minimal and near-minimal techniques have been incorporated in automated synthesis systems, but are known to require computational efforts which increase exponentially with flow table size. Other methods, requiring much less effort, produce assignments with far more state variables than minimal assigmnents. This table presents a practical method for generating near-minimal unicode single-transition-time state assignments for very large flow tables. The new technique has been programmed and thus used to generate assignments for tables of up to 400 cells. It is shown that resources required to generate practical assignments for very large tables increases almost linearly with flow table size using the procedure described.