Ring oscillator dynamic adjustments for auto calibration

• US 20050125181A1
• Filed: 01/25/2005
• Published: 06/09/2005
• Est. Priority Date: 08/15/2001
• Status: Active Grant

• Current Assignee: M-Red Inc. (Quest Patent Research Corporation)
• Original Assignee: Gallitzin Allegheny LLC (Intellectual Ventures LLC)
• Inventors: Schmidt, Dominik J., Norman, Robert D.
• Granted Patent: US 7,068,557 B2
• Time in Patent Office: Days
• US Class Current: 702/107
• CPC Class Codes: H03K 3/011 Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature to maintain energy constant H03K3/015
• CPC Class Codes: H03K 3/0315 Ring oscillators
• CPC Class Codes: H03L 1/00 Stabilisation of generator output against variations of physical values, e.g. power supply

Abstract

An apparatus compensates for voltage and temperature variations on an integrated circuit with: a voltage sensor having a digital voltage output; a temperature sensor having a digital temperature output; a register coupled to the voltage sensor and the temperature sensor, the register adapted to concatenate the digital voltage output and the temperature output into an address output; and a memory device having an address input coupled to the address output of the register, the memory device being adapted to store one or more corrective vectors.

Claims

1-20. -20. (canceled)

21. An integrated circuit, comprising:

a voltage sensor having a voltage output;

a temperature sensor having a temperature output; and

a memory to receive an input address based upon the voltage output and the temperature output, the memory to store compensation data.

22. The integrated circuit of claim 21, further comprising a register coupled to the voltage sensor and the temperature sensor, the register to form the input address from the voltage output and the temperature output.

23. The integrated circuit of claim 21, further comprising a wake-up oscillator coupled to the memory, the wake-up oscillator to periodically enable the memory to output a corrective vector.

24. The integrated circuit of claim 21, further comprising a ring oscillator coupled to an output of the memory.

25. The integrated circuit of claim 24, wherein the memory to provide an adjustment vector to the ring oscillator based on the current voltage and temperature of the integrated circuit.

26. The integrated circuit of claim 22, further comprising:

a processor; and

a multiplexer having a first input coupled to the processor and a second input coupled to the register and an output coupled to the memory, the multiplexer to provide the compensation data to the memory.

27. A method for dynamically adjusting for voltage variations on an integrated circuit, comprising:

periodically sensing a voltage value of the integrated circuit;

accessing a memory of the integrated circuit based on the voltage value, the memory to store compensation data comprising a plurality of adjustment values; and

dynamically adjusting a frequency of the integrated circuit using one of the adjustment values.

28. The method of claim 27, further comprising periodically sensing a temperature value of the integrated circuit.

29. The method of claim 28, further comprising combining the voltage and temperature values into a digital word.

30. The method of claim 29, further comprising addressing the memory using the digital word.

31. The method of claim 28, further comprising generating the compensation data by characterizing the integrated circuit.

32. The method of claim 31, wherein the characterizing further comprises varying the voltage and temperature over a predetermined range.

33. The method of claim 27, wherein the periodic sensing further comprises receiving a wake-up signal from a low power wake-up oscillator.

34. The method of claim 27, further comprising applying the one of the adjustment values to a ring oscillator.

35. The method of claim 34, further comprising switching delay elements of the ring oscillator based on the one of the adjustment values.

36. The method of claim 35, further comprising preventing the ring oscillator from glitching while switching the delay elements.

37. An integrated circuit comprising:

a voltage sensor to sense a voltage of the integrated circuit;

a memory coupled to the voltage sensor, the memory to store compensation data; and

an oscillator coupled to the memory to receive correction information therefrom, and to vary an operating parameter of the oscillator using the correction information.

38. The integrated circuit of claim 37, wherein the oscillator comprises a ring oscillator.

39. The integrated circuit of claim 37, further comprising a temperature sensor to sense the temperature of the integrated circuit.

40. The integrated circuit of claim 39, further comprising a register coupled to the voltage sensor and the temperature sensor, the register to form the input address from the digital voltage output and the temperature output.