Patents by Inventor David W. Boerstler
David W. Boerstler 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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Publication number: 20080246524Abstract: A Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: ApplicationFiled: June 17, 2008Publication date: October 9, 2008Applicant: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20080229270Abstract: A design structure for a Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: ApplicationFiled: May 29, 2008Publication date: September 18, 2008Applicant: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20080222585Abstract: A design structure embodied in a machine readable medium used in a design process includes an interleaved voltage-controlled oscillator, including a ring circuit of main logic inverter gates; a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates; wherein each delay element comprises a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages; and a proportional section for regulating signal transmission through at least one logic inverter gate; at least one temperature compensation circuit responsive to a compensating voltage input that is proportional to temperature; an electronic circuit in communication with the temperature compensation circuit and configured to provide a voltage signal responsive to temperature; an amplifier in connection with the electronic circuit to amplify the voltage signal; and a DC offset generator configured to adjust the voltage of theType: ApplicationFiled: May 23, 2008Publication date: September 11, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 7417480Abstract: A Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: GrantFiled: July 14, 2006Date of Patent: August 26, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20080191809Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: ApplicationFiled: April 7, 2008Publication date: August 14, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Publication number: 20080186104Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: ApplicationFiled: April 7, 2008Publication date: August 7, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 7391277Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: GrantFiled: July 20, 2006Date of Patent: June 24, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Publication number: 20080136480Abstract: An apparatus for extracting a maximum pulse width of a pulse width limiter is provided. The apparatus performs such extraction using a circuit that is configured to eliminate a majority of delay cells. The elimination of delay cells is made possible by replacing an OR gate in the circuit configuration with an edge triggered re-settable latch. The replacement of the OR gate with the edge triggered re-settable latch reduces the amount of chip area used in addition to the power consumption of the circuit.Type: ApplicationFiled: February 20, 2008Publication date: June 12, 2008Inventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7360135Abstract: An apparatus and method for automatically calibrating a duty cycle circuit for maximum performance. A chip level built-in circuit automatically calibrates the duty cycle correction (DCC) circuit setting for each chip. The chip level built-in circuit includes a clock generation macro unit, a simple duty cycle correction (DCC) circuit, an array slice and built-in self test unit, and a DCC circuit controller. A built-in self test provides results, i.e. pass or fail, of an array to the DCC circuit controller. If the result of the built-in self test is a pass, then the current DCC circuit controller's DCC control bit setting is set as the setting for the chip. If the result from the built-in self test is a fail, the DCC circuit controller's DCC control bits setting is incremented to a next setting and the self-test is performed again.Type: GrantFiled: August 31, 2007Date of Patent: April 15, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7358785Abstract: An apparatus and method for extracting a maximum pulse width of a pulse width limiter are provided. The apparatus and method of the illustrative embodiments performs such extraction using a circuit that is configured to eliminate the majority of the delay cells utilized in the circuit arrangement described in commonly assigned and co-pending U.S. patent application Ser. No. 11/109,090 (hereafter referred to as the '090 application). The elimination of these delay cells is made possible in one illustrative embodiment by replacing an OR gate in the circuit configuration of the '090 application with an edge triggered re-settable latch. The replacement of the OR gate with the edge triggered re-settable latch reduces the amount of chip area used in addition to the power consumption of the circuit.Type: GrantFiled: April 6, 2006Date of Patent: April 15, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20080018408Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: ApplicationFiled: July 20, 2006Publication date: January 24, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 7321651Abstract: A method, an apparatus, and a computer program are provided for generating an error detection state and correction of code patterns. Generally, conducting full speed testing of the dI/dt circuit in a low bandwidth lab environment is difficult. A circuit, however, can be employed that periodically detects the functionality of the dI/dt circuit to indicate success or failure. When errors are detected, the circuit allows for erroneous codes to be replaced with accurate ones. Using this circuit, conducting full speed testing of the dI/dt circuit in a low bandwidth lab environment can be more easily achieved.Type: GrantFiled: November 12, 2004Date of Patent: January 22, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7322001Abstract: An apparatus and method for automatically calibrating a duty cycle circuit for maximum performance. A chip level built-in circuit automatically calibrates the duty cycle correction (DCC) circuit setting for each chip. The chip level built-in circuit includes a clock generation macro unit, a simple duty cycle correction (DCC) circuit, an array slice and built-in self test unit, and a DCC circuit controller. A built-in self-test provides results, i.e. pass or fail, of an array to the DCC circuit controller. If the result of the built-in self test is a pass, then the current DCC circuit controller's DCC control bit setting is set as the setting for the chip. If the result from the built-in self test is a fail, the DCC circuit controller's DCC control bits setting is incremented to a next setting and the self-test is performed again.Type: GrantFiled: October 4, 2005Date of Patent: January 22, 2008Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20080012617Abstract: A Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: ApplicationFiled: July 14, 2006Publication date: January 17, 2008Inventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7289926Abstract: The present invention provides for a method for examining high-frequency clock-masking signal patterns at a reduced frequency. A first mode of a first shift register is selected. A plurality of bits is loaded on the first shift register at a first frequency. A second mode of the first shift register is selected. A first mode of a second shift register is selected. The plurality of bits is loaded on the second shift register. A second mode of the second shift register is selected. A first mode of a third shift register is selected. The plurality of bits is loaded on the third shift register. A second mode of the third shift register is selected and the plurality of bits is loaded from the third shift register at a second frequency, where the second frequency is lower than the first frequency, thereby providing for examining high-frequency clock-masking signal patterns at a reduced frequency.Type: GrantFiled: June 28, 2005Date of Patent: October 30, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7265600Abstract: The present invention provides for a system comprising a first stable voltage module configured to receive a first power supply from a first power supply domain and to generate a first stable voltage in response to the received first power supply. A second stable voltage module is configured to receive a second power supply from a second power supply domain and to generate a second stable voltage in response to the received second power supply. A first set of resistors is coupled to the first stable voltage module and configured in parallel. A second set of resistors is coupled to the second stable voltage module and configured in parallel. A set of capacitors is coupled in parallel to the first set of resistors and the second set of resistors and a plurality of level shifters are coupled to the second set of resistors.Type: GrantFiled: October 4, 2005Date of Patent: September 4, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Kazuhiko Miki, Jieming Qi
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Patent number: 7260491Abstract: A mechanism for measuring duty cycle of a signal under test in an integrated circuit device, such as a microprocessor or system-on-a-chip is provided. The mechanism generates a frequency which is proportional to the duty cycle and which can be measured using common lab or manufacturing equipment. The mechanism may be implemented using simple circuits in a standard complementary metal oxide semiconductor process which requires very little area and can be powered off when it is not being used. The mechanism may include, for example, a low pass filter, a voltage divider for providing calibration reference voltage signals, a voltage to frequency converter, a frequency divider for dividing a frequency signal output so that the frequency of the signal is within a predetermined range, and an output driver and output pad. From the frequency output signal, a duty cycle of the signal under test may be calculated using off-chip equipment.Type: GrantFiled: October 27, 2005Date of Patent: August 21, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7245161Abstract: An apparatus and method for verifying glitch-free operation of a multiplexer are provided. The apparatus includes a circuit having a plurality of flip-flop elements that receive as inputs the plurality of clock signals that are inputs to the multiplexer, and a corresponding synchronized output signal of a decoder generated based on control inputs to the decoder. The synchronized output signals from the decoder are used as trigger signals to the plurality of flip-flops. The flip-flops sample the clock signals based upon the trigger signals and provide outputs to a logic gate. The logic gate operates on the outputs from the flip-flops to generate an output signal indicative of whether glitch-free operation is verified or is not verified.Type: GrantFiled: September 15, 2005Date of Patent: July 17, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7245172Abstract: A level shifter apparatus and method for minimizing duty cycle distortion are provided. The level shifter includes a bank of comparators each having an associated threshold built into it. The comparators compare a difference in source voltages for two power domains to these built-in thresholds and output a signal indicative of whether the threshold is exceeded. The output signals from the comparators are provided to a thermometric decoder which generates control signals based on these output signals. The control signals are used to control stages in a level shifter for modifying the voltage output of the level shifter. Individual stages may be enabled to thereby monotonically modify the voltage output of the level shifter and thereby decrease a time required to achieve a voltage having a level that causes a state change in a driven circuit. As a result, duty cycle distortion is minimized and maximum operational frequency is increased.Type: GrantFiled: November 8, 2005Date of Patent: July 17, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Kazuhiko Miki, Jieming Qi
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Patent number: 7225092Abstract: An apparatus, a method, and a computer program are provided to measure the duty cycle of a clocking signal in a processor. Traditionally, variations in the duty cycles of clocks within microprocessors have been of considerable concern. By employing frequency dividers and AND gates, the duty cycles of clocks can be precisely measured and adjusted accordingly to account for variation that might occur. The measurements and adjustments, therefore, can improve the operation of a microprocessor or any other clocked semiconductor.Type: GrantFiled: October 21, 2004Date of Patent: May 29, 2007Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Kazuhiko Miki