MEASURING POWER CONSUMPTION IN AN INTEGRATED CIRCUIT

• US 20120130657A1
• Filed: 06/28/2011
• Published: 05/24/2012
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: ECKERT, Martin, FRECH, Roland, SIVIERO, Claudio, SUPPER, Jochen, TORREITER, Otto A., WINKEL, Thomas-Michael
• Granted Patent: US 9,709,625 B2
• Time in Patent Office: Days
• US Class Current: 702/61
• CPC Class Codes: G01R 31/2851 Testing of integrated circuits [IC] G01R31/317 takes precedence; testing individual devices G01R31/26; testing printed circuits G01R31/2801
• CPC Class Codes: G01R 31/2879 related to electrical aspects, e.g. to voltage or current supply or stimuli or to electrical loads
• CPC Class Codes: G01R 31/3004 Current or voltage test
• CPC Class Codes: G01R 31/3012 Built-In-Current test [BIC]
• CPC Class Codes: G01R 31/318575 Power distribution; Power saving

Abstract

A method for determining power consumption of a power domain within an integrated circuit is presented. In a first step, a local power supply impedance profile (Z(f)) of this power domain is determined. Subsequently, a local time-resolved power supply voltage (U(t)) is measured while a well-defined periodic activity is executed in power domain. A set of time-domain measured voltage data (U(t)) is thus accumulated and transformed into the frequency domain to yield a voltage spectrum (U(f)). A current spectrum I(t) is calculated from this voltage profile (U(f)) by using the power supply impedance profile Z(f) of this power domain as I(t)=F_f⁻¹{U(f)/Z(f)}. Finally, a time-resolved power consumption spectrum P(t) is determined from measured voltage spectrum U(t)) and calculated current spectrum (I(t)). This power consumption (P(t)) may be compared with a reference (P_ref(t)) to verify whether power consumption within power domain matches expectations.

Claims

1. A method for determining power consumption of a power domain within an integrated circuit, the method comprising:

determining a local power supply impedance profile (Z(f)) of said power domain;

measuring a local power supply voltage (U(t)) while executing a periodic activity specific to said power domain;

evaluating a voltage spectrum (U(f)) of said measured local power supply voltage (U(t));

calculating an associated power supply current (I(t)) from said impedance profile (Z(f)) and said voltage spectrum (U(f)); and

determining a power consumption spectrum (P(t)) from said power supply current (I(t)) and the measured power supply voltage (U(t)).

2. The method of claim 1, wherein the determining said local power supply impedance profile of said power domain comprises:

applying a repetitive activity in said power domain;

evaluating the temporal behavior of a current consumption (I₀(t)) caused by said repetitive activity;

calculating a corresponding current consumption spectrum (I₀(f));

measuring a local power supply voltage (U₀(t)) caused by said repetitive activity;

evaluating a voltage spectrum (U₀(f)) of said measured local power supply voltage (U0(t)); and

calculating said local power supply impedance profile (Z(f)) from said voltage and current spectra (U₀(f), I₀(f)).

3. The method of claim 2, wherein the applying the repetitive activity comprises periodically switching the system clock tree on and off.

4. The method of claim 2, wherein the evaluating the temporal behavior of the current consumption (I₀(t)) comprises obtaining quasi-static measurements of a leakage current (I₀^leak) and a current amplitude (I₀^ampl) of the repetitive activity.

5. The method of claim 1, further comprising comparing a power consumption spectrum P to a reference spectrum P_ref.

6. The method of claim 1, wherein the method is carried out during system power-on.

7. The method of claim 1, wherein the method is carried out periodically during system operation.

8. A system for determining power consumption of a power domain within an integrated circuit, the system comprising:

a memory for storing a local power supply impedance profile Z(f) of said power domain;

an Activity Stimulation System for executing a periodic activity specific to said power domain;

a Voltage Measurement System for measuring a local power supply voltage (U(t)) of said power domain;

a Fourier Transform System for evaluating a voltage spectrum (U(f)) of said measured local power supply voltage (U(t)) and for calculating associated current (I(t)) from said impedance profile (Z(f)) and said voltage spectrum (U(f); and

a Power Evaluation System for determining a power consumption (P(t)).

9. The system of claim 8, further comprising a Comparator for comparing said power consumption spectrum (P(t)) to a reference profile (P_ref(t)).

10. The system of claim 8, wherein the system is integrated into the integrated circuit.

11. The system of claim 10, wherein the Activity Stimulation System and the Voltage Measurement System reside on a chip with the integrated circuit, and the Comparator resides in a location outside the chip.