Progression of states numerically controlled oscillator
US5179348A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 22, 1991 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Aug 22, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/0321
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A numerically controlled oscillator includes a number of N-bit adders that perform parallel addition of a frequency setting word to an accumulated output. A first adder adds the frequency setting word to the accumulated output. A second adder adds a multiple of the frequency setting word to the accumulated output. Additional adders may be included to add other multiples of the frequency setting word to the accumulated output. The sum output of the adder in which the highest multiple of the frequency setting word is added is saved as the new accumulated output. The outputs of all the adders are saved and are mutliplexed out in sequence at a predetermined clock rate as a series of input values to a sine lookup table in a ROM. The outputs from the ROM form the digitized samples of a sine wave at the predetermined clock rate. The frequency setting word is applied to the adders at a reduced clock rate that is lower than the predetermined clock rate so that the adders operate at the reduced clock rate. Thus, the digitized samples of the sine wave are output at the predetermined clock rate that is greater than the clock rate at which the adders are required to operate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.