Abstract: An integrated circuit design tool apparatus includes a processing resource configured to support a circuit simulator, a circuit sensitivity optimiser and a circuit sensitivity calculator. The circuit sensitivity optimiser is adapted to communicate to the circuit simulator a first dynamic list of selected devices of the circuit; and a second dynamic list of selected process parameters associated with the selected devices of the first dynamic list. The circuit simulator is configured to communicate to the circuit sensitivity calculator, a performance metrics of the circuit in response thereto. The circuit sensitivity calculator is configured to determine one sensitivity coefficient for each device of the first dynamic list in response thereto. The circuit sensitivity calculator is further configured to determine and communicate to the circuit sensitivity optimiser a variance of the performance metrics and also adapted to gradually determine whether or not to further communicate with the circuit simulator.

Abstract: An integrated circuit design tool apparatus including a processing resource arranged to support a circuit simulator, a circuit simulator interrogator, and a well distance calculator is provided. The circuit simulator interrogator communicates first and second well distance values separately to the circuit simulator and receives first and second performance parameter value back from the circuit simulator interrogator in response. The well distance calculator determines a performance parameter limit value, and projects, substantially linearly, a well distance change value in respect of the performance parameter limit value using the first and second performance parameter values, the performance parameter limit value and a trial well distance change value. Also, a well distance change characterising equation using the well distance change value projected is used in order to obtain the minimum well distance value associated with the performance parameter limit value.