Abstract: A programmable logic device (PLD) comprises at least one configurable element, and a plurality of programmable logic elements for configuring the configurable element(s). Alternatively, a PLD comprises an interconnect structure and a plurality of programmable logic elements for configuring the interconnect structure. In either embodiment, at least one of the programmable logic elements includes N memory cells. A predetermined one of the N memory cells forms part of a memory slice, wherein at least a portion of each slice of the programmable logic device is allocated to either configuration data or user data memory. Typically, one memory slice provides one configuration of the programmable logic device. In accordance with one embodiment, a memory access port is coupled between at least one of the N memory cells and either one configurable element or the interconnect, thereby facilitating loading of new configuration data into other memory slices during the one configuration.

Abstract: In accordance with the present invention, a programmable array includes hierarchical configuration and state storage. The array comprises an active storage for an active configuration and an active state as well as an inactive storage for one or more inactive configurations and one or more inactive states. The array further comprises logic and routing configured by the active configuration. The logic includes a plurality of combinational elements and a plurality of sequential logic elements for providing the states. Bits are transferred between the active and the inactive storage.

Abstract: A programmable logic device (PLD) comprises a plurality of configurable logic blocks (CLBs), an interconnect structure for interconnecting the CLBs, and a plurality of programmable logic elements for configuring the CLBs and the interconnect structure. Each CLB includes a combinational element and a sequential logic element, wherein at least one programmable logic element includes a plurality of memory cells for configuring the combinational element and at least one programmable logic element includes a plurality of memory cells for configuring the sequential logic element. A micro register, which stores a plurality of intermediate states of one CLB or interconnect structure, is located at the output of a CLB, the input of a CLB, or elsewhere in the interconnect structure. The PLD includes means for disabling access to at least one of said plurality of memory elements. In one embodiment, the memory cells are RAM cells, whereas in other embodiments the memory cells are ROM cells, or a combination thereof.

Abstract: A method of time multiplexing a programmable logic device (PLD) includes inputting a design for the PLD and dividing an evaluation of the logic of the design into a plurality of micro cycles. The method further includes identifying the logic not within a critical path of the design and rescheduling the identified logic for evaluation in other micro cycles. Alternatively, if the PLD includes a plurality of combinational logic elements, the method further includes scheduling a combinational logic element in a micro cycle no earlier than all the combinational logic elements that generate the input signals to said combinational logic element.

Abstract: A PLD is operable in a variety of modes. In a first mode, the timeshare mode, the PLD remains at a single configuration for a plurality of user clock cycles. In a second mode, the logic engine mode, the PLD sequences through multiple configurations for each user cycle. In this mode, the period of time during which a configuration is active is called a micro cycle. In a third mode, the static mode, multiple configurations are programmed identically, so that the PLD performs the same function regardless of the configuration. Finally, the PLD is also operable in a combination mode, wherein part of the chip operates in one mode, for example, the static mode, and another part of the chip operates in the logic engine mode or the timeshare mode. In an alternative or co-existing embodiment, the PLD operates in one configuration mode during at least one user cycle and in another configuration mode during at least another user cycle.

Abstract: A programmable logic device (PLD) includes at least one configurable element, a plurality of programmable logic elements for configuring the configurable element(s), and a sequencer coupled to the plurality of programmable logic elements. Each programmable logic element typically includes a plurality of memory cells, wherein the sequencer accesses one of the plurality of memory cells during one step in a sequence of steps, each step initiated by one or more trigger signals. If the sequencer receives a plurality of trigger signals simultaneously, then the sequencer prioritizes these signals. Generally, each step provides one configuration of the PLD. In one embodiment, the sequence of steps includes less than all configurations of the PLD. In another embodiment, one trigger signal initiates a plurality of sequences of configurations.