Patents Represented by Law Firm E. Eric Hoffman, Skjerven, Morrill, MacPherson, Franklin & Friel Jeanette S Harms, Xilinx, Inc.
  • Patent number: 5818255
    Abstract: A carry logic circuit for a programmable logic device which uses a single function generator to create a carry propagate signal (P) and an output signal (S). The function generator includes a plurality of signal generation circuits, each of which is controlled by a first input signal (A) and a second input signal (B). One of the signal generation circuits is programmed to provide a desired carry propagate signal (P) in response to the first and second input signals (A,B). The carry propagate signal (P) is transmitted for use outside of the function generator to perform a carry propagation function for the carry logic circuit. The remaining signal generation circuits are programmed to generate one or more intermediate output signals in response to the first and second input signals (A,B). These intermediate output signals, in combination with carry propagate signal (P), are representative of the desired output signal (S).
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: October 6, 1998
    Assignee: Xilinx, Inc.
    Inventors: Bernard J. New, Danesh Tavana