The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 1987
Filed:
Aug. 31, 1984
Karl H Renner, Dallas, TX (US);
Alec J Morton, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A digital lattice filter includes a Y-adder (44) and a B-adder (106). The Y-adder (44) calculates the Y-values for a linear predictive coding voice compression technique and the B-adder (106) calculates the B-values. Each of the calculated B-values output by the B-adder (106) is input to a B-stack (118) for storage therein. The B-stack (118) delays the B-values for one sample period. Multiplier constants are contained in a K-stack (90) for output to both adders (44) and (106) for use in the multiplication operation. The final value is stored in a Y1-register (104). Each of the adders (44) and (106) are multiplexed to perform a multiplication operation followed by an addition operation to generate the respective Y- and B-values. A generated Y-value is stored in a Y-register (56) for use in the next sequential Y calculation. In addition, the generated Y-value is used as a multiplicand for generation of a B-value. Therefore, it is only necessary to store the Y-values for one clock cycle and the B-values for up to nine clock cycles, thus reducing the amount of storage space necessary. In addition, the use of two multiplexed adders reduces the required processing speed at each of the adders.