US5101487A
Expired / Lapsed
US
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Method for retrieving compressed data from a memory storing a look-up table
Assignee: Summagraphics Corp
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Filing: 1989-05-16
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Granted: 1992-03-31
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Expires: 2009-05-16
Abstract
Abstract A method for storing a k-bit output value for each of a plurality of m-bit input values in a memory having an n-bit word stored at each of 2 n n-bit addresses, wherein m, n and k are positive integers, m>n>k and m-n≧k, the method comprising the steps of storing a first k-bit output value corresponding to a first m-bit input value at a first n-bit address in the memory, and storing the 2n-m most significant bits of the first n-bit address at a second n-bit address, the stored 2n-m most significant bits of the first n-bit address occupying the 2n-m most significant bits at the second n-bit address, the first and second n-bit addresses being selected such that the n most significant bits of the first m-bit input value correspond to the n bits making up the second n-bit address and the m-n least significant bits of the first m-bit input value correspond to the m-n least significant bits making up the first n-bit address.
Inventors
- 👤 Thomas Zalenski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:11
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/0304; G06F3/0317
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
205 words
A computer implemented method for retrieving compressed data from a look-up table stored in a memory having 2 n addresses each capable of storing one n-bit word, where n is an integer, comprising the steps of: storing a first n-bit word at a first address of said memory and a second n-bit word at a second address of said memory, wherein said first and second n-bit words are different; inputting to said memory an n-bit code identifying said first address; outputting said first n-bit word in response to inputting of said n-bit code identifying said first address; inputting to said memory an n-bit code identifying said second address, wherein the n bits making up said n-bit code identifying said second address are derived from k bits of the n bits making up said first n-bit word, where k is an integer less than n; outputting said second n-bit word in response to inputting of said n-bit code identifying said second address; and detecting at least one of said n bits making up said outputted second n-bit word having a position in said second n-bit word which does not correspond to the position of any one of said k bits making up said first n-bit word.
Claim 2
Dependent Claim
205 words
A computer implemented method for retrieving compressed data from a look-up table stored in a memory having 2 n addresses each capable of storing one n-bit word, where n is an integer, comprising the steps of: storing a first n-bit word at a first address of said memory and a second n-bit word at a second address of said memory, wherein said first and second n-bit words are different; inputting to said memory an n-bit code identifying said first address; outputting said first n-bit word in response to inputting of said n-bit code identifying said first address; inputting to said memory an n-bit code identifying said second address, wherein the n bits making up said n-bit code identifying said second address are derived from k bits of the n bits making up said first n-bit word, where k is an integer less than n; outputting said second n-bit word in response to inputting of said n-bit code identifying said second address; and detecting at least one of said n bits making up said outputted second n-bit word having a position in said second n-bit word which does not correspond to the position of any one of said k bits making up said first n-bit word.
Claim 3
Dependent Claim
196 words
The method as defined in claim 1, further comprising the steps of: storing a third n-bit word at a third address of said memory, wherein said third n-bit word is different than each of said first and second n-bit words; inputting to said memory an n-bit code identifying said second address, wherein the n bits making up said n-bit code identifying said second address are not derived from said k bits of the n bits making up said first n-bit word; outputting said second n-bit word in response to inputting of said n-bit code identifying said second address; inputting to said memory an n-bit code identifying said third address, wherein the n bits making up said n-bit code identifying said third address comprise k bits of the n bits making up said second n-bit word; outputting said third n-bit word in response to inputting of said n-bit code identifying said third address; and detecting at least one of said n bits making up said outputted third n-bit word having a position in said third n-bit word which does not correspond to the position of any one of said k bits making up said second n-bit word.
Claim 4
Dependent Claim
23 words
The method as defined in claim 1, wherein n equals 8, k equals 5 and the number of said detected bits is 2.
Claim 5
Dependent Claim
24 words
The method as defined in claim 2, wherein n equals 8 , k equals 5 and the number of said detected bits is 2.
Claim 6
Dependent Claim
24 words
The method as defined in claim 1, wherein said first n-bit word is derived from n bits of data output by an electro-optical mouse.
References Cited (Backward Citations)
US3541541A
Cited
US3541521A
Cited
US3586396A
Cited
US3892963A
Cited
US4142180A
Cited
US4306232A
Cited
US4303914A
Cited
US4521772A
Cited
US4409479A
Cited
US4691199A
Cited
US4926314A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |