Abstract: Methods and apparatus for programmably powering down a structured application-specific integrated circuit are provided. At least one of the programmable layers of the structured ASIC that frequently provides some programmability as between or among a small number of alternative functions is used to provide this programmability.

Abstract: Providing ASIC equivalents of FPGAs is facilitated and made more efficient and economical by using an ASIC architecture including a plurality of so-called hybrid logic elements (“HLEs”), each of which can provide a portion of the full functionality of an FPGA logic element (“LE”). The functionality of each FPGA LE implementing a user's logic design can be mapped to one or more HLEs without re-synthesis of the user's logic. Only as many HLEs as are necessary are used to perform the functions of each LE. The one-for-one equivalence between each LE and either (1) one HLE or (2) a group of HLEs facilitates mapping (without re-synthesis) in either direction between FPGA and ASIC designs.

Abstract: Methods and apparatus for programmably powering down a structured application-specific integrated circuit are provided. At least one of the programmable layers of the structured ASIC that frequently provides some programmability as between or among a small number of alternative functions is used to provide this programmability.

Abstract: A mask-programmable logic device includes a macrocell having an external input/output port for “place-and-route” programming by addition of metallization layers. A programmable “fixed” layer allows the external input/output port to be isolated from the remainder of the macrocell so that it “floats,” allowing signals to be routed through the external input/output port when the macrocell is not in use, to reduce routing blockages. The macrocell also may have at least one internal input/output port, potentially connected to different logic circuits, and a programmable “fixed” layer that can be used to control which internal input/output port is connected to the external input/output port. By thus allowing multiple logic circuits to share a single external input/output port, routing blockages are reduced.

Abstract: Providing ASIC equivalents of FPGAs is facilitated and made more efficient and economical by using an ASIC architecture including a plurality of so-called hybrid logic elements (“HLEs”), each of which can provide a portion of the full functionality of an FPGA logic element (“LE”). The functionality of each FPGA LE implementing a user's logic design can be mapped to one or more HLEs without re-synthesis of the user's logic. Only as many HLEs as are necessary are used to perform the functions of each LE. The one-for-one equivalence between each LE and either (1) one HLE or (2) a group of HLEs facilitates mapping (without re-synthesis) in either direction between FPGA and ASIC designs.