John C. Costello has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: An output buffer comprising control circuit for reducing the amount of ground and/or power bounce noise. The output buffer further includes one or more driver devices. The output current of the driver device(s) is limited by providing an intermediate drive voltage to the control electrode of the driver device. A pass device (or a transmission gate) provides the intermediate drive voltage and also operates as a variable resistive device that limits the slew rate of the drive voltage. The operation of the pass device can be dependent on a signal level at the output of the output buffer. When the output has transitioned to a new logic state, the new logic level is fed back to change the operating state of the pass device, thus ensuring that the output voltage meets the output VOL and VOH specifications.
June 5, 1998
Date of Patent:
February 6, 2001
William B. Vest, Dirk A. Reese, Myron W. Wong, John C. Costello
Abstract: A macrocell for a programmable logic device includes circuitry for allowing a neighboring macrocell to borrow various numbers of the product terms of the macrocell. The macrocell can continue to make full use of its product terms that are not thus borrowed. This includes logically combining and registering the unborrowed product terms. The macrocell may include circuitry for feeding back to the AND array of the programmable logic device a combinatorial or registered signal of the macrocell, and also outputting such a combinatorial or registered signal from the macrocell. When a combinatorial signal is fed back, the register of the macrocell can be used for another signal of the macrocell.