Method and apparatus for measuring localized voltages on programmable integrated circuits
AssigneeXilinx, Inc.
InventorRobert O. Conn, Jr.
Life of this patent
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Abstract
A method is described for measuring localized operating temperatures and voltages on an integrated circuit. The integrated circuit includes an oscillator circuit with a frequency that varies with temperature and/or applied voltage. The frequency of the oscillator is then determined, using a constant voltage, for a number of temperatures to establish a known relationship between oscillation frequency and temperature. Once the relationship is known, a similar oscillator is included within or adjacent a second circuit of the integrated circuit. The operating temperature or operating voltage of the second circuit may then be determined by monitoring the frequency of the oscillator while the second circuit is operational.
Claims14
A method comprising:
- programming a programmable logic device to include a voltage-sensing circuit, the circuit having a characteristic that varies with applied voltage according to a known relationship;
- measuring the characteristic of the circuit;
- and
- determining the applied voltage based on the measured characteristic and the known relationship.
A method comprising:
- programming a programmable logic device to include an oscillator in a region of the programmable logic device, the oscillator having an oscillation frequency that varies with applied voltage;
- determining a relationship between the oscillation frequency and the applied voltage, wherein determining the relationship includes:
- programming the programmable logic device to include the oscillator circuit in a region of the programmable logic device;
- applying a first voltage to the programmable logic device;
- measuring the oscillation frequency of the oscillator to obtain a first oscillation frequency corresponding to the first voltage;
- changing the applied voltage to a second voltage;
- measuring the oscillation frequency of the oscillator to obtain a second oscillation frequency corresponding to the second voltage;
- and
- calculating the relationship using the first and second oscillation frequencies and the corresponding first and second voltages;
- and
- programming the programmable logic device to include a second circuit in the region.
A method comprising:
- programming a programmable logic device to include a first voltage-sensing circuit into a first region of the programmable logic device, the first voltage-sensing circuit having a characteristic that varies with applied voltage according to a relationship;
- measuring the characteristic of the voltage-sensing circuit;
- determining the applied voltage based on the measured characteristic and the relationship;
- and
- programming the programmable logic device to include a second voltage-sensing circuit in a second region of the programmable logic device.
Dependencies are inferred from the claim text.