Reciprocal arithmetic circuit with ROM table
Patent 5012438 Issued on April 30, 1991. Estimated Expiration Date: 
November 30, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 30, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3633018 3648038 3777132 3917935 Method and apparatus for effecting range transformation in a digital circuitry Method and circuit for computing reciprocals Patent #: 4823301 InventorApplicationNo. 443357 filed on 11/30/1989US Classes:708/654Multiplication by reciprocalExaminersPrimary: Shaw, Dale M.Assistant: Mai, Tan V. Attorney, Agent or FirmInternational ClassG06F 007/52Foreign Application Priority Data1988-12-08 JPAbstractA reciprocal arithmetic circuit for deriving the reciprocal of a divisor A includes a ROM table for converting upper-bit data AH supplied as an address to the approximation of the reciprocal 1/AH2 of the square thereof and outputting the same, a subtracter circuit for deriving a difference AH-AL between the upper-bit data AH and the lower-bit data AL of the divisor A, and a multiplier circuit for receiving an output 1/AH2 of the read only memory (ROM) table and an output AH-AL of the subtracter circuit and deriving the product 1/AH2. (AH-AL) thereof to make the output of the ROM table more nearly equal to the reciprocal 1/A of the divisor A. | |
