Noise modulation for on-chip noise measurement

• US 9,797,938 B2
• Filed: 03/28/2014
• Issued: 10/24/2017
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hejase, Jose A., Na, Nanju, Pham, Nam H., Walls, Lloyd A.
• Primary Examiner(s): Astacio-Oquendo, Giovanni
• Application Number:
  US14/228,472
• Publication Number:
  US 20150276838A1
• Time in Patent Office: 1,306 Days
• Field of Search: 324613, 324 7639, 3247503
• CPC Class Codes: G01R 29/26 Measuring noise figure; Measuring signal-to-noise ratio
• CPC Class Codes: G01R 31/001 Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing measuring electromagnetic fields G01R29/08; circuits for generating HV pulses in dielectric strength testing G01R31/14
• CPC Class Codes: G01R 31/3187 Built-in tests

Abstract

Functionality for estimating characteristics of an on-chip noise signal can be implemented on a processing module. An on-chip noise signal is determined at an on-chip determination point of a computer chip. The on-chip noise signal is converted to a frequency-varying signal using a voltage-controlled oscillator implemented on the computer chip. The frequency-varying signal is measured at an off-chip measurement point and frequency information is extracted from the frequency-varying signal. The frequency information is converted to a voltage level associated with the on-chip noise signal based on the relationship between an input voltage provided to the voltage-controlled oscillator and an output frequency generated by the voltage-controlled oscillator.

Claims

1. A device for estimating a voltage level of an on-chip noise signal of a computer chip, the device comprising:

a voltage-to-frequency conversion structure that represents a relationship between an input voltage provided to a voltage-controlled oscillator on the computer chip and an output frequency generated by the voltage-controlled oscillator; and

a noise estimation unit comprising at least one member of the group consisting of an integrated circuit and a processor with associated memory that is external to the computer chip, the noise estimation unit configured to;

receive a frequency-varying signal that is representative of the on-chip noise signal determined at a determination point on the computer chip;

extract frequency information from the frequency-varying signal; and

convert the frequency information to the voltage level associated with the on-chip noise signal based, at least in part, on the voltage-to-frequency conversion structure.

2. The device of claim 1, wherein the noise estimation unit configured to extract the frequency information from the frequency-varying signal and convert the frequency information to the voltage level associated with the on-chip noise signal comprises the noise estimation unit configured to:

execute windowing operations on the frequency-varying signal to yield a subset of the frequency-varying signal;

execute time-to-frequency domain conversion operations to convert the subset of the frequency-varying signal to a corresponding frequency domain signal; and

determine the voltage level associated with the on-chip noise signal based, at least in part, on the frequency information extracted from the frequency domain signal and the voltage-to-frequency conversion structure.

3. The device of claim 2, wherein the noise estimation unit configured to determine the voltage level associated with the on-chip noise signal comprises the noise estimation unit configured to:

determine that an amplitude of the frequency domain signal exceeds a predefined threshold at a first frequency of the frequency domain signal;

identify the first frequency as a resonant frequency of the frequency domain signal, wherein the frequency information includes the resonant frequency; and

convert the resonant frequency to the voltage level associated with the on-chip noise signal based, at least in part, on the voltage-to-frequency conversion structure.

4. The device of claim 2, wherein the noise estimation unit is further configured to:

determine a variation in the voltage level with time based, at least in part, on the frequency information, the voltage-to-frequency conversion structure, and a time interval that corresponds to the subset of the frequency-varying signal.

5. The device of claim 1, wherein the noise estimation unit is further configured to:

determine a reference output frequency of an output signal generated by the voltage-controlled oscillator for each of a plurality of reference direct current (DC) signals provided to the voltage-controlled oscillator; and

determine the voltage-to-frequency conversion structure based, at least in part, on the plurality of reference DC signals and the corresponding reference output frequency.

6. The device of claim 1, wherein the integrated circuit comprises a system on a chip.

7. The device of claim 1, wherein the integrated circuit comprises an application specific integrated circuit.

8. A system comprising:

a computer chip comprising a voltage-controlled oscillator configured to;

convert an on-chip noise signal determined at a determination point on the computer chip to a frequency-varying signal; and

provide the frequency-varying signal to an off-chip noise estimation unit that is external to the computer chip;

the off-chip noise estimation unit coupled with the computer chip, the off-chip noise estimation unit comprising at least one member of the group consisting of an integrated circuit and a processor with associated memory configured to;

extract frequency information from the frequency-varying signal received from the voltage-controlled oscillator; and

convert the frequency information to a voltage level associated with the on-chip noise signal based, at least in part, on a voltage-to-frequency conversion structure.

9. The system of claim 8, wherein the off-chip noise estimation unit configured to extract the frequency information from the frequency-varying signal and convert the frequency information to the voltage level associated with the on-chip noise signal comprises the off-chip noise estimation unit configured to:

execute windowing operations on the frequency-varying signal to yield a subset of the frequency-varying signal;

execute time-to-frequency domain conversion operations to convert the subset of the frequency-varying signal to a corresponding frequency domain signal;

determine that an amplitude of the frequency domain signal exceeds a predefined threshold at a resonant frequency of the frequency domain signal, wherein the frequency information includes the resonant frequency; and

convert the resonant frequency to the voltage level associated with the on-chip noise signal based, at least in part, on a relationship between an input voltage provided to the voltage-controlled oscillator and an output frequency generated by the voltage-controlled oscillator.

10. The system of claim 9, wherein the off-chip noise estimation unit is further configured to:

determine a variation in the voltage level with time based, at least in part, on the frequency information and a time interval that corresponds to the subset of the frequency-varying signal.

11. The system of claim 8, wherein the off-chip noise estimation unit is further configured to:

determine an output frequency of an output signal generated by the voltage-controlled oscillator for each of a plurality of reference direct current (DC) signals provided to the voltage-controlled oscillator; and

determine the voltage-to-frequency conversion structure based, at least in part, on the plurality of reference DC signals and the corresponding output frequency, wherein the off-chip noise estimation unit is configured to convert the frequency information to the voltage level associated with the on-chip noise signal using the voltage-to-frequency conversion structure.

12. The system of claim 8, wherein the computer chip further comprises a noise determination unit configured to:

determine the on-chip noise signal at the determination point on the computer chip; and

provide the on-chip noise signal as an input to the voltage-controlled oscillator.

13. The system of claim 8, wherein the integrated circuit comprises a system on a chip.

14. The system of claim 8, wherein the integrated circuit comprises an application specific integrated circuit.