Patents Assigned to National Semicondcutor Corporation
  • Patent number: 7616052
    Abstract: Adjustable gain circuits (AGCs) within serial filter stages are initialized to maximum gain. The output of each AGC is then sampled and converted to digital representation for use by control logic in setting the gain for the respective AGC. The gain adjustment decision for each AGC is performed in one shot, sequentially backwards from the last AGC, such that gain may be adapted simply and quickly within a number of cycles equal to the number of AGCs. Performance is enhanced by a fast-adapting cell in which capacitances are switched into the input path and feedback loop of an amplifier to reduce direct current gain within the transfer function through charge sharing dividing down the output voltage.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: November 10, 2009
    Assignee: National Semicondcutor Corporation
    Inventors: Shu-Ing Ju, Hee Wong
  • Patent number: 6490606
    Abstract: For use in a processor having a floating point unit (FPU) capable of managing denormalized numbers in floating point notation, logic circuitry for, and a method of, generating least significant (L), round (R) and sticky (S) bits for a denormalized number. In one embodiment, the system includes: (1) a bit mask decoder that produces a bit mask that is a function of a precision of the denormalized number and an extent to which the denormalized number is denormal and (2) combinatorial logic, coupled to the bit mask decoder, that performs logical operations with respect to a fraction portion of the denormalized number, the bit mask and at least one shifted version of the bit mask to yield the L, R and S bits.
    Type: Grant
    Filed: August 19, 1999
    Date of Patent: December 3, 2002
    Assignee: National Semicondcutor Corporation
    Inventors: Daniel W. Green, Atul Dhablania