DEVICE-UNDER-TEST POWER MANAGEMENT

• US 20090309556A1
• Filed: 06/12/2008
• Published: 12/17/2009
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Franco, Osvaldo, Cooper, Daniel J., Milhaupt, Robert W.
• Granted Patent: US 8,030,959 B2
• Time in Patent Office: Days
• US Class Current: 323/234
• CPC Class Codes: G01R 31/31721 Power aspects, e.g. power supplies for test circuits, power saving during test for scan test G01R31/318575

Abstract

One embodiment of the present invention includes a system for managing power to a plurality of devices-under-test (DUTs). The system comprises a DUT test system configured to perform at least one test associated with operation of the DUTs and to monitor current associated the at least one test of the plurality of DUTs. The DUT test system can communicate an instruction to a subset of the plurality of DUTs to cancel the at least one test if the monitored current is greater than a predetermined threshold. Each of the plurality of DUTs can comprise restart logic configured to restart the at least one test of the subset of the plurality of DUTs after being cancelled in response to the instruction.

Claims

1. A system for managing power to a plurality of devices-under-test (DUTs), the system comprising:

a DUT test system configured to perform at least one test associated with operation of the DUTs and to monitor current associated with the at least one test of the plurality of DUTs, the DUT test system communicating an instruction to a subset of the plurality of DUTs to cancel the at least one test if the monitored current is greater than a predetermined threshold, each of the plurality of DUTs comprising logic configured to restart the at least one test of the subset of the plurality of DUTs after being cancelled in response to the instruction.

2. The system of claim 1, wherein each of the plurality of DUTs comprises power management logic that is configured to disconnect at least one power voltage in response to a broadcast command provided from the DUT test system upon the current being greater than the predetermined threshold.

3. The system of claim 2, wherein each of the plurality of DUTs also comprises a test elapse timer that increments during the at least one test, and wherein the broadcast command from the DUT test system comprises a time value, each of the plurality of DUTs having an incremented value of the test elapse timer that is less than the time value being included in the subset of the plurality of DUTs.

4. The system of claim 3, wherein each of the plurality of DUTs includes a predetermined cutoff time, such that the power management logic is configured to disconnect the at least one power supply voltage in response to the incremented value of the test elapse timer exceeding the predetermined cutoff time.

5. The system of claim 1, wherein each of the plurality of DUTs comprises a back-off timer configured to activate in response to the instruction to cancel the at least one test, each of the subset of the plurality of DUTs being configured to restart the at least one test in response to the back-off timer achieving a preset time value.

6. The system of claim 5, wherein the preset time value is randomly selected in response to a broadcast command from the DUT test system upon the current being greater than the predetermined threshold.

7. The system of claim 6, wherein the broadcast command from the DUT test system comprises a scale-factor, each of the plurality of DUTs being configured to apply the scale-factor to a respective back-off timer to adjust a random timing range of the respective back-off timer.

8. The system of claim 6, wherein the broadcast command comprises a predetermined delay time, the back-off timer being configured to begin incrementing upon expiration of the predetermined delay time.

9. The system of claim 1, wherein the DUT test system comprises a plurality of power supplies and a plurality of switches, each of the plurality of switches being configured to couple at least one of the plurality of DUTs to a respective one of the plurality of power supplies.

10. The system of claim 9, wherein the DUT test system is configured to control at least one of the plurality of switches to disconnect at least one of the DUTs from a respective one of the plurality of power supplies upon the current being greater than the predetermined threshold to select the subset of the plurality of DUTs, the subset of the plurality of DUTs being configured to individually determine a time when to restart the at least one test in response to detecting being disconnected from the respective one of the plurality of power supplies.

11. The system of claim 9, wherein the DUT test system is configured to individually monitor the current for each of the plurality of power supplies.

12. The system of claim 1, wherein the DUT test system is further configured to programmably set the predetermined threshold as a function of a dynamic current range of the at least one test.

13. The system of claim 1, wherein the plurality of DUTs are configured to generate a random number upon initiation of the at least one test by the DUT test system, the random number corresponding to a time at which a portion of the plurality of DUTs concurrently begin the at least one test.

14. A method for managing power to a plurality of devices-under-test (DUTs), the method comprising:

monitoring a current associated with at least one test of each of the plurality of DUTs;

canceling the at least one test for a subset of the plurality of DUTs in response to the current exceeding a predetermined threshold; and

individually restarting the at least one test for the subset of the plurality of DUTs based on a random heuristic algorithm.

15. The method of claim 14, further comprising activating a back-off timer for each of the DUTs in the subset of the plurality of DUTs in response to canceling the at least one test, wherein individually restarting comprises individually restarting the at least one test for each of the DUTs in the subset of the plurality of DUTs upon the respective back-off timer achieving a respective random preset time value that is defined by the random heuristic algorithm.

16. The method of claim 15, further comprising setting a scale-factor to adjust a random timing range of the back-off timer for the plurality of DUTs.

17. The method of claim 14, further comprising:

incrementing a test elapse timer for each of the plurality of DUTs upon each of the plurality of DUTs initiating the at least one test;

broadcasting a time value to each of the plurality of DUTs if the current exceeds the predetermined threshold; and

selecting each of the DUTs of the plurality of DUTs having an incremented value of the test elapse timer that is less than the broadcasted time value to be in the subset of the plurality of DUTs.

18. The method of claim 14, wherein monitoring the current comprises monitoring a current associated with each of a plurality of portions of the plurality of DUTs, and wherein canceling the at least one test comprises decoupling power from a subset of a respective one of the plurality of portions of the plurality of DUTs upon the current of the respective one of the plurality of portions of the plurality of DUTs exceeding the predetermined threshold.

19. The method of claim 14, further comprising programmably setting the predetermined threshold as a function of a dynamic current range of the at least one test.

20. A system for managing power to a plurality of devices-under-test (DUTs), the system comprising:

means for monitoring a test current associated with at least one test of each of the plurality of DUTs;

means for removing the test current from a subset of the plurality of DUTs upon the test current exceeding a predetermined threshold; and

means for selecting the subset based on an elapsed time that each of the plurality of DUTs has individually performed the at least one test.

21. The system of claim 20, further comprising means for independently re-applying the test current for each DUT in the subset of the plurality of DUTs.

22. The system of claim 20, further comprising means for providing the test current to a respective portion of the plurality of DUTs, wherein the means for monitoring the test current comprises respective means for monitoring the test current associated with the respective one of the plural means for providing, and wherein the means for removing the test current comprises means for removing the test current from a subset of the respective portion of the plurality of DUTs upon a respective test current exceeding the predetermined threshold.