Monolithic PC audio circuit with enhanced digital wavetable audio synthesizer
US5659466A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1994 |
| Grant date | Aug 19, 1997 |
| Priority date | — |
| Expiry date | Nov 2, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H2250/611
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A digital wavetable audio synthesizer is described. The synthesizer can generate up to 32 high-quality audio digital signals or voices, including delay-based effects, at either a 44.1 KHz sample rate or at sample rates compatible with a prior art wavetable synthesizer. The synthesizer includes an address generator which has several modes of addressing wavetable data. The address generator's addressing rate controls the pitch of the synthesizer's output signal. The synthesizer performs a 10-bit interpolation, using the wavetable data addressed by the address generator, to interpolate additional data samples. When the address generator loops through a block of data, the signal path interpolates between the data at the end and start addresses of the block of data to prevent discontinuities in the generated signal. A synthesizer volume generator, which has several modes of controlling the volume, adds envelope, right offset, left offset, and effects volume to the data. The data can be placed in one of sixteen fixed stereo pan positions, or left and right offsets can be programmed to place the data anywhere in the stereo field. The left and right offset values can also be programmed to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.