Method for determining information about the internal workings of a chip based on electro-magnetic emissions therefrom

• US 20070120571A1
• Filed: 11/03/2006
• Published: 05/31/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: VNS Portfolio LLC
• Original Assignee: VNS Portfolio LLC
• Inventors: Huie, John
• Granted Patent: US 7,554,352 B2
• Time in Patent Office: Days
• US Class Current: 324/512
• CPC Class Codes: G01R 31/002 where the device under test is an electronic circuit
• CPC Class Codes: G01R 31/31727 Clock circuits aspects, e.g. test clock circuit details, timing aspects for signal generation, circuits for testing clocks G01R31/31725 takes precedence; concerning scan test G01R31/318552, for tester hardware G01R31/31922

Abstract

A novel a method for determining the internal operation of an integrated circuit (IC) includes measuring electromagnetic (EM) emissions from the integrated circuit chip and analyzing the EM emissions. In a particular method, the EM emissions from the IC are measured using an RF close end probe. In a particular method, the electromagnetic emissions are measured with the IC configured in various ways. In the normal operating mode, the emissions are measured while the IC is provided with power and any external clock signal(s). After measuring the emissions of the IC in normal operating mode, the IC is reconfigured by disabling the external clock signal(s) to the IC and remeasuring the emissions. The external clock signal is disabled by disconnecting the power to the IC, disabling the external clock signal, and then reconnecting power to the IC. In yet a third test mode, the external clock signal is reenabled while power continues to be supplied to the IC. Information about the presence and/or proper functioning of internal clocks of the IC can be determined by analyzing the spectral scan data obtained in one or more of the three test modes.

Claims

1. A method for determining the internal operation of an integrated circuit comprising:

measuring electromagnet emissions from said integrated circuit; and

analyzing said electromagnetic emissions.

2. A method according to claim 1, wherein said step of measuring electromagnetic emissions from said integrated circuit includes using an RF probe.

3. A method A method according to claim 2, wherein said step of measuring electromagnetic emissions from said integrated circuit includes using an RF close end probe.

4. A method according to claim 1, further comprising configuring said integrated circuit prior to said step of measuring said electromagnetic emissions.

5. A method according to claim 4, wherein said step of configuring said integrated circuit includes placing said integrated circuit in its normal operating mode.

6. A method according to claim 5, wherein said step of placing said integrated circuit chip in its normal operating mode includes providing power and any external clock signal to said integrated circuit.

7. A method according to claim 4, further comprising:

configuring said integrated circuit prior to said step of measuring said electromagnetic emissions;

reconfiguring said integrated circuit after said step of measuring said electromagnetic emissions; and

remeasuring said electromagnetic emissions from said integrated circuit after said step of reconfiguring said integrated circuit.

8. A method according to claim 4, wherein said step of configuring said integrated circuit includes:

providing power to said integrated circuit; and

disabling any external clock signal to said integrated circuit.

9. A method according to claim 8, wherein said step of disabling any external clock signal to said integrated circuit includes:

disconnecting power to said integrated circuit;

disabling any external clock signal to said integrated circuit; and

reconnecting power to said integrated circuit.

10. A method according to claim 4, wherein said step of configuring said integrated circuit includes reenabling a disabled external clock signal to said integrated circuit while power is supplied to said integrated circuit.

11. A method according to claim 4, further comprising:

configuring said integrated circuit by supplying power and any external clock signal to said integrated circuit prior to measuring said electromagnetic emissions;

reconfiguring said integrated circuit after said step of measuring said electromagnetic emissions by disconnecting power to said integrated circuit, disabling any external clock signal to said integrated circuit, and reconnecting power to said integrated circuit; and

remeasuring said electromagnetic emissions from said integrated circuit after reconfiguring said integrated circuit.

12. A method according to claim 11, further comprising:

reconnecting any external clock signal to said integrated circuit following said step of remeasuring said electromagnetic emissions; and

remeasuring said electromagnetic emissions from said integrated circuit a second time after said step of reconnecting any external clock signal.

13. A method according to claim 1, wherein said step of analyzing said electromagnetic emissions includes determining whether said electromagnetic emissions are below a predetermined RFI level.

14. A method according to claim 1, wherein:

said step of measuring electromagnetic emissions includes measuring the amplitude of said electromagnetic emissions over a range of frequencies; and

said step of analyzing said electromagnetic emissions includes identifying frequencies corresponding to amplitudes greater than a predetermined amplitude.

15. A method according to claim 14, wherein said step of analyzing said electromagnetic emissions includes comparing said identified frequencies to a predetermined set of frequencies to determine whether one or more clocks of said integrated circuit are operating properly.

16. A method according to claim 1, wherein said step of analyzing said electromagnetic emissions includes comparing said identified frequencies to sets frequencies associated with known devices to determine whether any of said known devices are embedded in said integrated circuit.

17. A method according to claim 14, further comprising:

disabling any external clock signal to said integrated circuit after said step of measuring said electromagnetic emissions from said integrated circuit;

remeasuring said electromagnetic emissions from said integrated circuit while said external clock signal is disabled;

identifying frequencies corresponding to amplitudes greater than said predetermined amplitude in said remeasured electromagnetic emissions; and

comparing said identified frequencies of said measured electromagnetic emissions with said identified frequencies of said remeasured electromagnetic emissions.

18. A method according to claim 1, wherein said step of measuring said electromagnetic emissions includes measuring said electromagnetic emissions at several different locations with respect to said integrated circuit.

19. An electronically readable medium having code embodied therein for causing an electronic device to perform the method of claim 1.

20. An apparatus for determining the internal operation of an integrated circuit, comprising:

a probe for sensing electromagnetic radiation from said integrated circuit; and

a spectrum capture device operative to convert said electromagnetic radiation sensed by said probe into electronic data; and

a spectrum analyzer operative to process said electronic data to provide information about the internal operation of said integrated circuit.

21. An apparatus according to claim 20, further comprising a display for presenting said data from said spectrum analyzer.

22. An apparatus according to claim 21, wherein said spectrum analyzer is operative to present said data on said display in the form of an amplitude versus frequency graph.

23. An apparatus according to claim 20, further comprising:

a processing unit for executing code and processing data; and

memory for storing said code, said code including said spectrum capture routine and said spectrum analyzer.

24. An apparatus according to claim 23, wherein said spectrum capture device is further operative to control the position of said probe.

25. An apparatus according to claim 20, wherein said spectrum capture device is further operative to selectively interrupt electrical power to said integrated circuit.

26. An apparatus according to claim 20, wherein said spectrum capture device is further operative to selectively enable and disable an external clock signal to said integrated circuit.

27. An apparatus according to claim 20, wherein said spectrum capture device is operative to store said electronic data as records indicative of an electromagnetic spectrum emitted by said integrated circuit.

28. An apparatus according to claim 20, wherein:

said spectrum capture device is operative to capture a first set of spectrum data from said integrated circuit and a second set of spectrum data from said integrated circuit;

said spectrum analyzer is operative to compare said first set of spectrum data to said second set of spectrum data to identify at least one predetermined difference.

29. An apparatus according to claim 28, wherein said spectrum capture device is operative to selectively disable an external clock signal to said integrated circuit during the capture of one of said first set of spectrum data and said second set of spectrum data.

30. An apparatus according to claim 20, wherein said spectrum analyzer is operative to compare said electronic data to electronic data indicative of an internal clock of said integrated circuit operating properly.

31. An apparatus according to claim 20, wherein said spectrum analyzer is operative to compare said electronic data with sets of electronic data associated with known electronic devices to determine whether one or more of said known electronic devices are embedded in said integrated circuit.

32. An apparatus for determining the internal operation of an integrated circuit, comprising:

a probe for sensing electromagnetic radiation from said integrated circuit; and

a spectrum capture device operative to convert said electromagnetic radiation sensed by said probe into electronic data; and

means for analyzing said data to obtain information about the internal operation of said integrated circuit.

33. A computer readable medium having a data structure stored therein, said data structure comprising:

a first field containing data indicative of a particular electronic device; and

a second field containing data indicative of an electromagnetic emission from said particular electronic device.