US4969118A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Floating point unit for calculating A=XY+Z having simultaneous multiply and add
Assignee: International Business Machines Corp
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Filing: 1989-01-13
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Granted: 1990-11-06
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Expires: 2009-01-13
Abstract
Abstract A single floating point that produces the result A×B+C with A, B and C being floating point numbers. The operand C is shifted in parallel with the beginning phases of the multiplication. The result is produced after a single addition and normalization, reducing hardware, delay and rounding errors.
Inventors
- 👤 Robert K. Montoye
- 👤 John Cocke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:52
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/38; G06F7/48; G06F7/544; G06F7/5443; G06F7/483; G06F7/499; G06F7/49936; G06F7/49942; G06F7/49947
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
An apparatus for performing the floating point operation (A×B+C) said apparatus comprising: means for multiplying A×B to generate a first partial results, alignment means for aligning C with said first partial results, said multiplication being performed in parallel with said alignment of C operation; said multiplying means and said alignment means being connected to means for adding said first partial result and said aligned C; means connected to said alignment means and said adding means for incrementing said C operand when said C operand has higher significance than a sum of said first partial results; and normalizing means connected to said incrementing means and said adding means.
Claim 2
Independent Claim
107 words
An apparatus for performing the floating point operation (A×B+C) said apparatus comprising: means for multiplying A×B to generate a first partial results, alignment means for aligning C with said first partial results, said multiplication being performed in parallel with said alignment of C operation; said multiplying means and said alignment means being connected to means for adding said first partial result and said aligned C; means connected to said alignment means and said adding means for incrementing said C operand when said C operand has higher significance than a sum of said first partial results; and normalizing means connected to said incrementing means and said adding means.
Claim 3
Dependent Claim
19 words
The apparatus according to claim 1 wherein said multiplier means and said adder have approximately the same processing delays.
Claim 4
Dependent Claim
28 words
The apparatus according to claim 2 wherein said multiplier means and said adder means have input to output delay proportional to the logarithm of the mantissa input bits.
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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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |