US5821773A
Expired / Lapsed
US
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Look-up table based logic element with complete permutability of the inputs to the secondary signals
Assignee: Cadence Design Systems Inc
•
Filing: 1995-09-06
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Granted: 1998-10-13
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Expires: 2015-09-06
Abstract
Abstract A logic element for a programmable logic device. The logic element includes a look-up table (400) for implementing logical functions, a programmable delay block (415), a storage block (430) configurable as a latch or a flip-flop, and a diagnostic shadow latch (435). A plurality of inputs (410) to the logic element and complements of these inputs are available to control the secondary functions of the storage block (430).
Inventors
- 👤 Kevin A. Norman
- 👤 Rakesh H. Patel
- 👤 Stephen P. Sample
- 👤 Michael R. Butts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:57
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/173; H03K19/177; H03K19/17724; H03K19/17728; H03K19/1733; H03K19/1737
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
98 words
In a programmable logic device, a logic element comprising: a look-up table for implementing logical functions coupled to a multiplexer; a storage block, coupled to said look-up table, wherein said storage block stores an output of said look-up table; a first plurality of inputs, programmably coupled to said multiplexer and programmably coupled to said storage block; a second plurality of inputs, programmably coupled to said storage block, wherein said second plurality of inputs are complements of said first plurality of inputs; a combinatorial output, coupled to said look-up table; and a registered output, coupled to said storage block.
Claim 2
Dependent Claim
98 words
In a programmable logic device, a logic element comprising: a look-up table for implementing logical functions coupled to a multiplexer; a storage block, coupled to said look-up table, wherein said storage block stores an output of said look-up table; a first plurality of inputs, programmably coupled to said multiplexer and programmably coupled to said storage block; a second plurality of inputs, programmably coupled to said storage block, wherein said second plurality of inputs are complements of said first plurality of inputs; a combinatorial output, coupled to said look-up table; and a registered output, coupled to said storage block.
Claim 3
Dependent Claim
122 words
In a programmable logic device, a logic element comprising: a look-up table for implementing logical functions coupled to a multiplexer; a storage block, programmably coupled to said look-up table, wherein said storage block stores an output of said look-up table, wherein said storage block comprises clock enable, clear, preset, and clock inputs; a first plurality of inputs, programmably coupled to said multiplexer and programmably coupled to said clock enable, clear, preset, and clock inputs; and a second plurality of inputs, programmably coupled to said clock enable, clear, preset, and clock inputs, wherein said second plurality of inputs are complements of said first plurality of inputs; a combinatorial output, coupled to said look-up table; and a registered output, coupled to said storage block.
Claim 4
Dependent Claim
122 words
In a programmable logic device, a logic element comprising: a look-up table for implementing logical functions coupled to a multiplexer; a storage block, programmably coupled to said look-up table, wherein said storage block stores an output of said look-up table, wherein said storage block comprises clock enable, clear, preset, and clock inputs; a first plurality of inputs, programmably coupled to said multiplexer and programmably coupled to said clock enable, clear, preset, and clock inputs; and a second plurality of inputs, programmably coupled to said clock enable, clear, preset, and clock inputs, wherein said second plurality of inputs are complements of said first plurality of inputs; a combinatorial output, coupled to said look-up table; and a registered output, coupled to said storage block.
Claim 5
Dependent Claim
42 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; and a programmable delay block, coupled to said programmable function generator, wherein said programmable delay block programmably delays an output from said programmable function generator.
Claim 6
Dependent Claim
42 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; and a programmable delay block, coupled to said programmable function generator, wherein said programmable delay block programmably delays an output from said programmable function generator.
Claim 7
Dependent Claim
54 words
The logic element of claim 3 further comprising: a storage block for storing said output from said programmable function generator, wherein said delay block is coupled between said programmable function generator and said storage block, wherein said programmable delay block programmably delays a signal passed from said programmable function generator to said storage block.
Claim 8
Dependent Claim
31 words
The logic element of claim 4 further comprising: a multiplexer, coupled between said delay block and said storage block, wherein said multiplexer selectively couples said delay block to said storage block.
Claim 9
Dependent Claim
42 words
The logic element of claim 5 wherein said multiplexer selectively couples a secondary logic block to said storage block, wherein a path from said secondary logic block through said multiplexer to said storage block does not pass through said programmable delay block.
Claim 10
Dependent Claim
42 words
The logic element of claim 6 wherein said multiplexer selectively couples a diagnostic shadow latch to said storage block, wherein a path from said diagnostic shadow latch through said multiplexer to said storage block does not pass through said programmable delay block.
Claim 11
Dependent Claim
46 words
The logic element of claim 4 further comprising: a multiplexer, wherein said multiplexer selectively couples said programmable function generator to an output of said logic element, wherein an output path from said programmable function generator to said multiplexer does not pass through said programmable delay block.
Claim 12
Dependent Claim
40 words
The logic element of claim 8 wherein said multiplexer selectively couples said storage block to an output of said logic element, wherein an output path from said storage block to said multiplexer does not pass through said programmable delay block.
Claim 13
Dependent Claim
61 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a diagnostic shadow latch, coupled to a configuration loading pin of said programmable function generator, wherein said diagnostic shadow latch stores and provides diagnostic data; and a storage block coupled to an output of said programmable function generator and to said diagnostic shadow latch.
Claim 14
Dependent Claim
61 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a diagnostic shadow latch, coupled to a configuration loading pin of said programmable function generator, wherein said diagnostic shadow latch stores and provides diagnostic data; and a storage block coupled to an output of said programmable function generator and to said diagnostic shadow latch.
Claim 15
Dependent Claim
87 words
A logic element in a programmable logic device comprising: a programmable function generator for implementing logical functions; a diagnostic shadow latch, coupled to a plurality of configuration loading pins of said programmable function generator, wherein said diagnostic shadow latch stores and provides diagnostic data; and a storage block, coupled to said programmable function generator, wherein said storage block stores an output of said programmable function generator, wherein said diagnostic shadow latch is coupled to an input of said storage block and an output of said storage block.
Claim 16
Dependent Claim
87 words
A logic element in a programmable logic device comprising: a programmable function generator for implementing logical functions; a diagnostic shadow latch, coupled to a plurality of configuration loading pins of said programmable function generator, wherein said diagnostic shadow latch stores and provides diagnostic data; and a storage block, coupled to said programmable function generator, wherein said storage block stores an output of said programmable function generator, wherein said diagnostic shadow latch is coupled to an input of said storage block and an output of said storage block.
Claim 17
Dependent Claim
68 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a storage block, coupled to said programmable function generator, said storage block for storing said output from said programmable function generator; and a diagnostic shadow latch, coupled to an input of said storage block and an output of said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 18
Dependent Claim
68 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a storage block, coupled to said programmable function generator, said storage block for storing said output from said programmable function generator; and a diagnostic shadow latch, coupled to an input of said storage block and an output of said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 19
Dependent Claim
49 words
The logic element of claim 12 further comprising: a multiplexer, coupled between said programmable function generator and said storage block and coupled between said diagnostic shadow latch and said storage block, wherein said multiplexer selectively couples said programmable function generator and said diagnostic shadow latch to said storage block.
Claim 20
Dependent Claim
23 words
The logic element of claim 13 further comprising: a plurality of control inputs, coupled to control said multiplexer and said diagnostic shadow latch.
Claim 21
Dependent Claim
71 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, wherein said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block.
Claim 22
Dependent Claim
71 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, wherein said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block.
Claim 23
Dependent Claim
30 words
The logic element of claim 15 further comprising: a diagnostic shadow latch, coupled to said storage block, wherein said storage block selectively stores an output from said diagnostic shadow latch.
Claim 24
Dependent Claim
77 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; a first plurality of inputs, coupled to said programmable function generator and said secondary logic block; and a second plurality of inputs, coupled to said secondary logic block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 25
Dependent Claim
77 words
A logic element for a programmable logic device comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; a first plurality of inputs, coupled to said programmable function generator and said secondary logic block; and a second plurality of inputs, coupled to said secondary logic block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 26
Dependent Claim
91 words
The logic element of claim 17 further comprising: a storage block, coupled to selectively store an output of said programmable function generator or an output of said secondary logic block; wherein a selected one of said first plurality of inputs controls a preset input of said storage block and said secondary logic block; and wherein a selected one of said second plurality of inputs controls said preset input of said storage block and said secondary logic block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 27
Dependent Claim
91 words
The logic element of claim 17 further comprising: a storage block, coupled to selectively store an output of said programmable function generator and an output of said secondary logic block; wherein a selected one of said first plurality of inputs controls a clear input of said storage block and said secondary logic block; and wherein a selected one of said second plurality of inputs controls said clear input of said storage block and said secondary logic block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 28
Dependent Claim
93 words
A logic element for a programmable logic device, comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block, wherein an output of said secondary logic block may be programmably coupled through said storage block to an output of said logic element.
Claim 29
Dependent Claim
93 words
A logic element for a programmable logic device, comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block, wherein an output of said secondary logic block may be programmably coupled through said storage block to an output of said logic element.
Claim 30
Dependent Claim
92 words
A logic element for a programmable logic device, comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block, wherein said programmable function generator is coupled to said secondary logic block via a direct path, not passing through said storage block.
Claim 31
Dependent Claim
92 words
A logic element for a programmable logic device, comprising: a programmable function generator for implementing logical functions; a secondary logic block, coupled to said programmable function generator, wherein said secondary logic block implements logical functions; and a storage block, coupled to said programmable function generator and said secondary logic block, said storage block selectively stores an output from said programmable function generator or an output from said secondary logic block, wherein said programmable function generator is coupled to said secondary logic block via a direct path, not passing through said storage block.
Claim 32
Dependent Claim
16 words
A system comprising a programmable logic device having a logic element as recited in claim 3.
Claim 33
Dependent Claim
124 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a programmable delay block, coupled between said look-up table and said storage block, said programmable delay block for programmably delaying a signal passed from said look-up table to said storage block.
Claim 34
Dependent Claim
124 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a programmable delay block, coupled between said look-up table and said storage block, said programmable delay block for programmably delaying a signal passed from said look-up table to said storage block.
Claim 35
Dependent Claim
143 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; a first plurality of inputs, programmably coupled to control said look-up table and a control input of said storage block; and a second plurality of inputs, programmably coupled to control said control input of said storage block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 36
Dependent Claim
143 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; a first plurality of inputs, programmably coupled to control said look-up table and a control input of said storage block; and a second plurality of inputs, programmably coupled to control said control input of said storage block, wherein said second plurality of inputs are complements of said first plurality of inputs.
Claim 37
Dependent Claim
18 words
The logic element of claim 24, wherein the control input is a preset input of said storage block.
Claim 38
Dependent Claim
19 words
The logic element of claim 24, wherein the control input is a clock enable input of said storage block.
Claim 39
Dependent Claim
18 words
The logic element of claim 24, wherein the control input is a clock input of said storage block.
Claim 40
Dependent Claim
57 words
The logic element of claim 27 further comprising: a first plurality of clock inputs, programmably coupled to said clock input of said storage block; and a second plurality of clock inputs, programmably coupled to said clock input of said storage block, wherein said second plurality of clock inputs are complements of said first plurality of clock inputs.
Claim 41
Dependent Claim
18 words
The logic element of claim 24, wherein the control input is a clock input of said storage block.
Claim 42
Dependent Claim
116 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions: a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmably configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to said look-up table and said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 43
Dependent Claim
116 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions: a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmably configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to said look-up table and said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 44
Dependent Claim
122 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to an input of said storage block and an output of said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 45
Dependent Claim
122 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmable configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to an input of said storage block and an output of said storage block, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 46
Dependent Claim
119 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmably configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to a plurality of configuration loading pins for said look-up table, wherein said diagnostic shadow latch stores and provides diagnostic data.
Claim 47
Dependent Claim
119 words
A logic element for a programmable logic device comprising: a look-up table for implementing logical functions; a storage block, coupled to said look-up table, said storage block storing an output from said look-up table, said storage block programmably configurable as a latch in a first mode, wherein said latch is responsive to a level-sensitive input, said storage block programmable configurable as a register in a second mode, wherein said register is responsive to an edge-triggered input; a combinatorial output, coupled to said look-up table; a registered output, coupled to said storage block; and a diagnostic shadow latch, coupled to a plurality of configuration loading pins for said look-up table, wherein said diagnostic shadow latch stores and provides diagnostic data.
References Cited (Backward Citations)
US3473160A
Cited
US3761695A
Cited
US3783254A
Cited
US3806891A
Cited
US4020469A
Cited
US4124899A
Cited
US4124899B1
Cited
US4286173A
Cited
US4298980A
Cited
US4366393A
Cited
US4293919A
Cited
US4428060A
Cited
US4476560A
Cited
US4597042A
Cited
US4717912A
Cited
US4488259A
Cited
US4546273A
Cited
US4667325A
Cited
USRE34363E
Cited
US4617479A
Cited
US4617479B1
Cited
US4609986A
Cited
US4642487A
Cited
US4706216A
Cited
US4677318A
Cited
US4713792A
Cited
US4649539A
Cited
US4701920A
Cited
US4912342A
Cited
US4871930A
Cited
US4899067A
Cited
US5036473A
Cited
US5661662A
Cited
US5657241A
Cited
US5612891A
Cited
US5109353A
Cited
US5644515A
Cited
US5329470A
Cited
US5477475A
Cited
US5488316A
Cited
US5175859A
Cited
US5121006A
Cited
US5241224A
Cited
US5355369A
Cited
US5336950A
Cited
US5436575A
Cited
US5550782A
Cited
US5260610A
Cited
US5260611A
Cited
US5392296A
Cited
US5352123A
Cited
US5414377A
Cited
US5452239A
Cited
US5375086A
Cited
US5317212A
Cited
US5350954A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-12 | 2002-04-13 | 2002-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-12 | 2006-04-13 | 2006-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-12 | 2010-04-13 | 2010-10-13 | $7700.00 | Window Closed / Lapsed |