Some embodiments provide a reconfigurable integrated circuit (“IC”). This IC has several reconfigurable circuits, each having several configurations for several configuration cycles. The reconfigurable circuits include several time-extending reconfigurable circuits. During the operation of the IC, each particular time-extending reconfigurable circuit maintains at least one of its configurations over at least two contiguous cycles, in order to allow a signal to propagate through a signal path, which contains the particular time-extending circuit, within a desired amount of time. Some embodiments provide a method of designing a reconfigurable IC that has several reconfigurable circuits, each having several configurations and operating in several reconfiguration cycles. The method identifies a signal path through the IC that does not meet a timing constraint. The signal path includes several circuits, one of which is a particular reconfigurable circuit. The method then maintains a configuration of the particular reconfigurable circuit constant over at least two contiguous reconfiguration cycles in order to reduce signal delay through the signal path and thereby satisfy the timing constraint.
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