Structure and method for generating a clock enable signal in a PLD

The invention provides a structure and method of generating a clock enable signal in a programmable logic device (PLD). A first embodiment of the invention comprises a clock enable circuit implemented such that the critical paths have only two levels of logic. In this embodiment, the critical paths are implemented in dedicated logic while other portions of the clock enable circuit are implemented using programmable logic. According to another embodiment of the invention, the clock enable circuit is located near the center of a first edge of the device. A first plurality of output registers are located along the first edge on either side of the clock enable circuit, with additional output registers being located along the two adjacent half-edges. Programmable interconnection points (PIPs) permit a clock enable interconnect line along the first edge to be programmably extended to the additional output registers. In another embodiment, the clock enable circuit is duplicated in two opposite edges of the device.