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1. WO1997031363 - PC AUDIO SYSTEM WITH FREQUENCY COMPENSATED WAVETABLE DATA

Publication Number WO/1997/031363
Publication Date 28.08.1997
International Application No. PCT/US1997/002811
International Filing Date 21.02.1997
Chapter 2 Demand Filed 12.09.1997
IPC
G10H 7/00 2006.01
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
7Instruments in which the tones are synthesised from a data store, e.g. computer organs
G10H 7/02 2006.01
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
7Instruments in which the tones are synthesised from a data store, e.g. computer organs
02in which amplitudes at successive sample points of a tone waveform are stored in one or more memories
CPC
G10H 2230/031
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS
2230General physical, ergonomic or hardware implementation of electrophonic musical tools or instruments, e.g. shape or architecture
025Computing or signal processing architecture features
031Use of cache memory for electrophonic musical instrument processes, e.g. for improving processing capabilities or solving interfacing problems
G10H 2240/275
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS
2240Data organisation or data communication aspects, specifically adapted for electrophonic musical tools or instruments
171Transmission of musical instrument data, control or status information; Transmission, remote access or control of music data for electrophonic musical instruments
201Physical layer or hardware aspects of transmission to or from an electrophonic musical instrument, e.g. voltage levels, bit streams, code words or symbols over a physical link connecting network nodes or instruments
275Musical interface to a personal computer PCI bus, "peripheral component interconnect bus"
G10H 7/004
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS
7Instruments in which the tones are synthesised from a data store, e.g. computer organs
002using a common processing for different operations or calculations, and a set of microinstructions (programme) to control the sequence thereof
004with one or more auxiliary processor in addition to the main processing unit
G10H 7/02
GPHYSICS
10MUSICAL INSTRUMENTS; ACOUSTICS
HELECTROPHONIC MUSICAL INSTRUMENTS
7Instruments in which the tones are synthesised from a data store, e.g. computer organs
02in which amplitudes at successive sample points of a tone waveform are stored in one or more memories
Applicants
  • ADVANCED MICRO DEVICES, INC. [US]/[US]
Inventors
  • HEWITT, Larry
Agents
  • MILLER, Louise, K.
  • PICKER, Madeline, Margaret
Priority Data
08/604,55821.02.1996US
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) PC AUDIO SYSTEM WITH FREQUENCY COMPENSATED WAVETABLE DATA
(FR) SYSTEME AUDIO DE MICRO-ORDINATEUR A COMPENSATION EN FREQUENCE DES DONNEES DE TABLEAUX D'ONDES
Abstract
(EN)
The PC audio circuit (10) described interfaces with and provides audio enhancement to a host personal computer of the type including a central processor, system memory and a system bus. The PC audio circuit (10) includes a digital signal processor (DSP) (16) for processing wavetable data and generating digital audio signals for a plurality of voices. The wavetable data is stored in the host computer's system memory and transferred in portions, as needed by the DSP (16) to a smaller, low-cost cache memory (22) included with the PC audio circuit (10). The DSP (16) processes several frames of data samples for an active voice before processing another voice. Processing in this manner alleviates concerns about the percentage use of system bus bandwidth and the maximum allowable system bus latency. These concerns are further alleviated by deriving frequency compensated wavetable data and storing it in system memory to be retrieved by the DSP (16) for generating digital audio signals having high frequency ratios. Digital audio signals generated for each active voice are accumulated in cache memory (22). When the digital audio signals for all active voices have been accumulated, the accumulated data is transmitted from the cache memory (22) to an external digital-to-analog converter. Since wavetable data is stored in system memory, the cache memory (22) is smaller and less expensive than the local memory in prior art PC audio circuits. Thus, the described PC audio circuit (10) has a lower overall cost.
(FR)
Le circuit audio (10) de micro-ordinateur de la présente invention décrit des interfaces avec un micro-ordinateur hôte et apporte des améliorations à un tel micro-ordinateur hôte du type à processeur central, mémoire système et bus système. Ce circuit audio (10) de micro-ordinateur comporte un processeur de signal numérique (DSP) (16) permettant de traiter des données de tableaux d'ondes et de générer des signaux audio numériques correspondant à une pluralité de voix. Le procédé consiste à stocker dans la mémoire système de l'ordinateur hôte les données de tableaux d'ondes et à les transférer partie après partie suivant ce dont le DSP (16) a besoin vers une antémémoire (22) bon marché et plus petite incorporée au circuit audio (10) du micro-ordinateur. Le DSP (16) traite plusieurs trames d'échantillons de données correspondant à une voix active avant de traiter une autre voix. En procédant de cette façon, on évite les difficultés afférent au pourcentage d'occupation de la largeur de bande du système et au temps de latence maximum autorisé du bus système. On évite encore mieux ces difficultés en extrayant des données de tableaux d'ondes compensées en fréquence et en les stockant dans la mémoire système en vue de leur récupération par le DSP (16) qui ira générer des signaux audio numériques caractérisés par des débits haute fréquence. Le procédé consiste ensuite à faire, en antémémoire (22), un cumul des signaux audio numériques de chacune des voix actives. Une fois terminé le cumul des signaux audio numériques correspondant à toutes les voix actives, les données de cumul sont transmises de l'antémémoire (22) à un dénumériseur externe. Le fait de stocker dans la mémoire système les données de tableaux d'ondes permet d'utiliser une antémémoire (22) plus petite et moins cher que la mémoire locale des circuits audio pour micro-ordinateurs selon l'état antérieur de la technique, ce qui fait que le circuit audio (10) pour micro-ordinateur de l'invention coûte dans l'ensemble moins cher.
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