US5342990A
Expired / Lapsed
US
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Digital sampling instrument employing cache-memory
Assignee: Creative Technology Ltd
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Filing: 1992-05-11
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Granted: 1994-08-30
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Expires: 2012-05-11
Abstract
Abstract A digital sampling instrument for multi-channel interpolatative playback of digital audio data stored in a waveform memory provides improved interpolation of musical sounds by use of a cache memory. The present invention includes a plurality of interpolator circuits utilizing a single waveform memory where each of the interpolator circuits produces a unique bus request signal which is responsive to a unique bus acknowledge signal to determine which of the interpolator circuits has control of the waveform memory at any given waveform memory cycle.
Inventors
- 👤 David P. Rossum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:00
CPC Classifications
G; G10; G10H; G10H7/00; G10H7/08; G10H7/12; G10H2230/00; G10H2230/025; G10H2230/031; G10H2250/00; G10H2250/131; G10H2250/145; G10H2250/541; G10H2250/545; G10H2250/621
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
97 words
A digital sampling instrument for the multichannel Nth order interpolative playback as output samples of digital audio data samples stored in a waveform memory comprising: coefficient logic means for generating N coefficients for each channel for each of said output samples, cache memory means for storing at least n waveform memory data samples for each channel, convolution means for computing a sum of N products of the contents of said cache memory means times said coefficients for each of several ones of said channels, and means for outputting said sum of products for each of said channels.
Claim 2
Dependent Claim
97 words
A digital sampling instrument for the multichannel Nth order interpolative playback as output samples of digital audio data samples stored in a waveform memory comprising: coefficient logic means for generating N coefficients for each channel for each of said output samples, cache memory means for storing at least n waveform memory data samples for each channel, convolution means for computing a sum of N products of the contents of said cache memory means times said coefficients for each of several ones of said channels, and means for outputting said sum of products for each of said channels.
Claim 3
Dependent Claim
15 words
An instrument as in claim 1 wherein said cache memory is a dual port memory.
Claim 4
Dependent Claim
16 words
An instrument as in claim 1 wherein said cache memory is comprises two single port memories.
Claim 5
Dependent Claim
17 words
An instrument as in claim 1 wherein said cache memory is of size N samples per channel.
Claim 6
Dependent Claim
17 words
An instrument as in claim 1 wherein said cache memory is of size N+1 samples per channel.
Claim 7
Dependent Claim
24 words
An instrument as in claim 1 also including a priority circuit for determining which channel's current address is used to load said cache memory.
Claim 8
Dependent Claim
18 words
An instrument as in claim 6 wherein said priority circuit includes two levels of priority for each channel.
Claim 9
Dependent Claim
32 words
An instrument as in claim 1 also including an address register file containing the integer part of a current address for each channel, and the required cache update size for each channel.
Claim 10
Dependent Claim
42 words
An instrument as in claim 8 wherein said address register file is responsive to an address update unit which increments said current address, and also responsive to a memory access unit which address the waveform memory at said integer part current address.
Claim 11
Dependent Claim
17 words
An instrument as in claim 8 including a cache base address stored in said address register file.
Claim 12
Dependent Claim
16 words
An instrument in claim 1 wherein said waveform memory includes a plurality of different memory types.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-29 | 1998-02-28 | 1998-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-29 | 2002-02-28 | 2002-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-29 | 2006-02-28 | 2006-08-30 | $7700.00 | Window Closed / Lapsed |