Patent ID: 7441212

Claim:
A method of identifying a one-hot encoded state machine in a netlist representing a user design, the method comprising: identifying a group of circuit elements in the netlist, wherein each circuit element has at least one feedback path, wherein a feedback path for a first circuit element in the group comprises an electrically traceable path from an output of the first circuit element through at least one other circuit element of the group to an input of the first circuit element; identifying a set of at least one register in the group of circuit elements; identifying a subset of the set of at least one register in the group of circuit elements, wherein identifying the subset includes: determining a number of one-states for each register in the set of at least one register in the group of circuit elements, sorting the set of at least one register in the group of circuit elements according to the number of one-states for each register, and identifying, from the sorted set of at least one register in the group of circuit elements, a subset comprising at most one register having a value of one for each state; identifying a set of at least one input for the registers of the subset; identifying a set of state transition logic in the group of circuit elements and associated with the subset of registers; computing a set of reachable states from an initial state for the subset of registers using the set of inputs and the set of state transition logic; and creating state machine information specifying at least a portion of the behavior of a state machine implemented by the group of circuit elements.