1. A method of operating a configurable circuit of an integrated circuit (IC), the method comprising: a) performing a first operation by the configurable circuit based on a first configuration data set; b) generating a user-design signal within the IC; c) when the user-design signal has a value from a set of values, performing a second operation by the configurable circuit based on a second configuration data set, after the first operation; and d) when the user-design signal does not have a value from said set of values, performing a third operation by the configurable circuit based on a third configuration data set, after the first operation.