Patents by Inventor David Edward Jefferson
David Edward Jefferson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6815981Abstract: A programmable logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.Type: GrantFiled: February 6, 2003Date of Patent: November 9, 2004Assignee: Altera CorporationInventors: Richard G. Cliff, Srinivas T. Reddy, David Edward Jefferson, Rina Raman, L. Todd Cope, Christopher F. Lane, Joseph Huang, Francis B. Heile, Bruce B. Pedersen, David Wolk Mendel, Craig Schilling Lytle, Robert Richard Noel Bielby, Kerry Veenstra
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Publication number: 20030128051Abstract: A programmable logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.Type: ApplicationFiled: February 6, 2003Publication date: July 10, 2003Inventors: Richard G. Cliff, Srinivas T. Reddy, David Edward Jefferson, Rina Raman, L. Todd Cope, Christopher F. Lane, Joseph Huang, Francis B. Heile, Bruce B. Pedersen, David Wolk Mendel, Craig Schilling Lytle, Robert Richard Noel Bielby, Kerry Veenstra
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Publication number: 20030016053Abstract: A programmable logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.Type: ApplicationFiled: April 8, 2002Publication date: January 23, 2003Inventors: Richard G. Cliff, Srinivas T. Reddy, David Edward Jefferson, Rina Raman, L. Todd Cope, Christopher F. Lane, Joseph Huang, Francis B. Heile, Bruce B. Pedersen, David Wolk Mendel, Craig Schilling Lytle, Robert Richard Noel Bielby, Kerry Veenstra
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Patent number: 6392438Abstract: A programmable logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.Type: GrantFiled: October 6, 2000Date of Patent: May 21, 2002Assignee: Altera CorporationInventors: Richard G. Cliff, Srinivas T. Reddy, David Edward Jefferson, Rina Raman, L. Todd Cope, Christopher F. Lane, Joseph Huang, Francis B. Heile, Bruce B. Pedersen, David Wolk Mendel, Craig Schilling Lytle, Robert Richard Noel Bielby, Kerry Veenstra
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Patent number: 6225823Abstract: A programmable logic device has a plurality of conductors extending around its periphery for use in providing at least some of the signals needed for control of input/output (“I/O”) pins which are also disposed around the periphery of the device. These control signals may include clock signals, output enable signals, clock enable signals, clear signals, or the like. The conductors that thus extend around the periphery are segmented into plural segments that can either be used independently of one another or programmably stitched together and therefore used together.Type: GrantFiled: March 24, 2000Date of Patent: May 1, 2001Assignee: Altera CorporationInventors: Christopher F. Lane, Srinivas T. Reddy, Andy L. Lee, David Edward Jefferson
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Patent number: 6107825Abstract: A programmable logic device has a plurality of conductors extending around its periphery for use in providing at least some of the signals needed for control of input/output ("I/O") pins which are also disposed around the periphery of the device. These control signals may include clock signals, output enable signals, clock enable signals, clear signals, or the like. The conductors that thus extend around the periphery are segmented into plural segments that can either be used independently of one another or programmably stitched together and therefore used together.Type: GrantFiled: May 29, 1998Date of Patent: August 22, 2000Assignee: Altera CorporationInventors: Christopher F. Lane, Srinivas T. Reddy, Andy L. Lee, David Edward Jefferson
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Patent number: 5847617Abstract: A variable-path-length voltage-controlled oscillator circuit is provided. The oscillator circuit has a ring oscillator formed from a series of voltage-controlled inverter stages. The path length (i.e., the number of inverter stages) in the ring is selected based on path length configuration data stored in memory. The selected path length determines the nominal or center frequency of operation of the ring oscillator. The output frequency of the oscillator circuit is voltage-tuned about this center frequency by varying the delay of each inverter stage in the ring oscillator path. Various types of voltage-controlled inverter stages may be used, including current-starved inverter stages, variable-capacitive-load inverter stages, and differential-delay inverter stages. The voltage-controlled oscillator circuit may be used in a phase-locked loop on a programmable logic device for frequency synthesis or to eliminate clock skew.Type: GrantFiled: August 11, 1997Date of Patent: December 8, 1998Assignee: Altera CorporationInventors: Srinivas T. Reddy, David Edward Jefferson, Richard G. Cliff, Cameron McClintock
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Patent number: 5699020Abstract: A loop circuit such as a delay lock loop or a phase lock loop includes circuitry for changing the strength of the lock after lock has been achieved. Before lock is achieved, the strength of the charge pump circuitry that controls the charge in the low-pass filter in the loop may be relatively weak. After lock has been achieved, the strength of the charge pump circuit may be increased so that the circuit can maintain its locked condition in a noisy environment.Type: GrantFiled: June 20, 1996Date of Patent: December 16, 1997Assignee: Altera CorporationInventor: David Edward Jefferson
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Patent number: 5642082Abstract: A loop circuit such as a delay lock loop or a phase lock loop includes circuitry for detecting when the output signal of the low-pass filter in the loop has either risen to a voltage which is relatively close to the power voltage of the circuit or has fallen to a voltage which is relatively close to the ground voltage of the circuit. In either case the circuitry reverses the significance of the phase frequency detector output signals that control whether the output voltage of the low-pass filter rises or falls. Alternatively or in addition, the phase frequency detector may be reset. Coarser adjustments may be made to the loop circuit downstream from the low-pass filter in response to a recurrence of the low-pass filter output voltage reaching either of the detected voltages mentioned above.Type: GrantFiled: June 20, 1996Date of Patent: June 24, 1997Assignee: Altera CorporationInventor: David Edward Jefferson