Sine/cosine generator and method
Patent 5276633 Issued on January 4, 1994. Estimated Expiration Date: 
August 14, 2012. 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.
August 14, 2012. 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 ReferencesSuppression of spurious frequency components in direct digital frequency synthesizer Sin/cos generator implementation Patent #: 5113361 InventorsAssigneeApplicationNo. 930926 filed on 08/14/1992US Classes:708/276TrigonometricExaminersPrimary: Mai, Tan V.Attorney, Agent or FirmInternational ClassG06F 001/02AbstractA sine/cosine generator with coarse and fine angles having compressed sine and cosine read only memories (ROMS) by use of symmetry of coarse angles about π/4 and, optionally, symmetry of fine angles about 0. The output of the ROMs directly feed multiplexers for utilization of the compressed storage. Addressing of complementary coarse angles is with one's complementing of the address and of complementary fine angles is with two's commplementing of the address. Fine sines and cosines are stored in recoded version for direct use in multipliers for computations using the sum of angles formulas. | |
