Patent US4845499A successfully refreshed from Google Patents.
US4845499A
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Method for generating PCM logarithmic values from linear values
Assignee: GTE Communication Systems Corp
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Filing: 1987-11-02
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Granted: 1989-07-04
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Expires: 2007-11-02
Abstract
Abstract A method for generating PCM logarithmic values from linear values and storing these values in memory for efficient and rapid data retrieval is shown. This is an off-line method of generating the contents of a programmable read only memory for rapid on-line conversions from linear to logarithmic PCM values by an ISDN system. This method generates either negative or positive PCM values. An initial value and memory address are determined. Next, memory address is incremented and is PCM value decremented. The resulting PCM value is stored at successive locations throughout the memory. Each PCM value comprises a step of a segment. These operations are iterated for each of the segments required for conversion for both positive and negative PCM values.
Inventors
- 👤 Donovan A. Bruce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:08
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/561; H04M3/568
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
A method for generating the PCM logarithmic values from corresponding linear values said generated values being stored in a memory, said method for generating comprising the steps of: first storing a predefined PCM logarithmic value in a memory location addressed by a first index value; first incrementing said first index value; first decrementing said predefined PCM logarithmic value; second storing said decremented PCM logarithmic value in a memory location addressed by said incremented first index value; first iterating said steps of first incrementing, first decrementing and second storing for sequentially storing each said PCM logarithmic value of a segment; second incrementing said first index value; second decrementing said PCM logarithmic value; third storing said decremented PCM logarithmic value in a memory location addressed by said incremented first index value; second iterating said steps of second incrementing, second decrementing and third storing for sequentially storing each said PCM logarithmic value of a segment; and third iterating said steps of second incrementing, second decrementing, third storing and second iterating for predetermined number of segments.
Claim 2
Independent Claim
172 words
A method for generating the PCM logarithmic values from corresponding linear values said generated values being stored in a memory, said method for generating comprising the steps of: first storing a predefined PCM logarithmic value in a memory location addressed by a first index value; first incrementing said first index value; first decrementing said predefined PCM logarithmic value; second storing said decremented PCM logarithmic value in a memory location addressed by said incremented first index value; first iterating said steps of first incrementing, first decrementing and second storing for sequentially storing each said PCM logarithmic value of a segment; second incrementing said first index value; second decrementing said PCM logarithmic value; third storing said decremented PCM logarithmic value in a memory location addressed by said incremented first index value; second iterating said steps of second incrementing, second decrementing and third storing for sequentially storing each said PCM logarithmic value of a segment; and third iterating said steps of second incrementing, second decrementing, third storing and second iterating for predetermined number of segments.
Claim 3
Dependent Claim
30 words
A method for generating as claimed in claim 1, wherein there is further included the step of first initializing said first index value equal to an initial memory address location.
Claim 4
Dependent Claim
23 words
A method for generating as claimed in claim 2, said initial memory address location being equal to zero for negative PCM logarithmic values.
Claim 5
Dependent Claim
24 words
A method for generating as claimed in claim 3, said initial memory address location being equal to 2000 hexadecimal for positive PCM logarithmic values.
Claim 6
Dependent Claim
32 words
A method for generating as claimed in claim 4, wherein there is further included the step of second initializing said predefined PCM logarithmic value equal to 7F hexadecimal for said negative values.
Claim 7
Dependent Claim
35 words
A method for generating as claimed in claim 5, wherein there is further included the step of third initializing said predefined PCM logarithmic value equal to a value of FF hexadecimal for said positive values.
Claim 8
Dependent Claim
31 words
A method for generating as claimed in claim 6, wherein there is further included the step of first setting a number of PCM logarithmic values in a segment equal to 16.
Claim 9
Dependent Claim
25 words
A method for generating as claimed in claim 7, wherein there is further included the step of third initializing a step value equal to one.
Claim 10
Dependent Claim
42 words
A method for generating as claimed in claim 8, said step of first storing including the steps of: first determining whether said step value is equal to one; and third incrementing said step value for said step value being equal to one.
Claim 11
Dependent Claim
58 words
A method for generating as claimed in claim 9, said step of first iterating including the steps of: second determining whether said step value has achieved a maximum count; third determining whether all PCM logarithmic values of said first segment have been calculated; and fourth incrementing a segment count by one for said completion of said first segment.
Claim 12
Dependent Claim
23 words
A method for generating as claimed in claim 10, said step of third storing including the step of fifth incrementing said step value.
Claim 13
Dependent Claim
44 words
A method for generating as claimed in claim 11, said step of second iterating including the steps of: fourth determining whether said step value has achieved said maximum count; and fifth determining whether all the PCM logarithmic values of a segment have been calculated.
Claim 14
Dependent Claim
35 words
A method for generating as claimed in claim 12, said step of third iterating including the steps of: sixth incrementing said segment count; and sixth determining whether said segment count has achieved a maximum count.
Claim 15
Dependent Claim
20 words
A method for generating as claimed in claim 13, said maximum count of said step value being equal to 16.
Claim 16
Dependent Claim
20 words
A method for generating as claimed in claim 14, said maximum count of said segment count being equal to 8.
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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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |