Calibrating device performance within an integrated circuit

• US 8,653,844 B2
• Filed: 03/07/2011
• Issued: 02/18/2014
• Est. Priority Date: 03/07/2011
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Sadoughi, Sharmin, Ahn, Jae-Gyung
• Primary Examiner(s): Nguyen, Tung X
• Application Number:
  US13/042,122
• Publication Number:
  US 20120229203A1
• Time in Patent Office: 1,079 Days
• Field of Search: 32476201-7621, 32475001-7503, 257/48, 438 14- 18
• US Class Current: 324/750.3
• CPC Class Codes: H01L 22/22 Connection or disconnection of sub-entities or redundant parts of a device in response to a measurement testing and repair of stores after manufacture including at wafer scale G11C29/00; fuses per se H01L23/525
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H03K 17/12 Modifications for increasing the maximum permissible switched current
• CPC Class Codes: H03K 17/18 Modifications for indicating state of switch

Abstract

A multi-fingered device can be calibrated for performance. The multi-fingered device can include a first finger configured to remain active and a second finger that is initially deactivated concurrent with the first finger being active. A measure of degradation for the multi-fingered device within an IC can be determined. The measure of degradation can be compared with a degradation threshold. Responsive to determining that the measure of degradation meets the degradation threshold, a finger of the multi-fingered device can be activated.

Claims

1. A method of calibrating performance of a multi-fingered device within an integrated circuit (IC), the method comprising:

determining a measure of degradation for the multi-fingered device within the IC, wherein a first finger of the multi-fingered device is active and a second finger of the multi-finger device is initially deactivated;

comparing the measure of degradation with a degradation threshold; and

responsive to determining that the measure of degradation meets the degradation threshold, activating the second finger of the multi-fingered device by coupling a gate of the second finger to a data signal also coupled to a gate of the first finger.

2. The method of claim 1, further comprising:

selecting the measure of degradation to comprise an amount of time that the multi-fingered device is active; and

selecting the degradation threshold to be a predetermined amount of time.

3. The method of claim 2, further comprising:

determining the amount of time that the multi-fingered device is active according to a number of clock cycles counted within a counter implemented within the integrated circuit, wherein the number of clock cycles is compared with a threshold number of clock cycles representing the predetermined amount of time of the degradation threshold.

4. The method of claim 1, further comprising:

selecting the measure of degradation to comprise threshold voltage of the multi-fingered device; and

selecting the degradation threshold to be a level of threshold voltage of the multi-fingered device that is greater than a reference level of threshold voltage.

5. The method of claim 1, further comprising:

selecting the measure of degradation to comprise drain saturation current of the multi-fingered device; and

selecting the measure of degradation to comprise a level of drain saturation current of the multi-fingered device that is less than a reference level of drain saturation current.

6. The method of claim 1, wherein activating a finger of the multi-fingered device further comprises activating a plurality of fingers of the multi-fingered device.

7. A multi-fingered device for implementation within an integrated circuit, the multi-fingered device comprising:

a first finger configured to remain active;

a second finger that is initially deactivated concurrent with the first finger being active,

wherein the second finger is configured for activation during operation of the integrated circuit; and

a switch coupled to the second finger, wherein the switch selectively couples a gate of the second finger to a data signal also coupled to a gate of the first finger.

8. The multi-fingered device of claim 7, further comprising:

a finger activation circuit configured selectively activate the second finger of the multi-fingered device responsive to detecting a minimum degradation in the multi-fingered device,

wherein the second finger is initially deactivated and is activated responsive to detecting the minimum degradation of the multi-fingered device.

9. The multi-fingered device of claim 8, wherein the finger activation circuit comprises:

a control circuit configured to provide a control signal to the switch responsive to detecting the minimum degradation.

10. The multi-fingered device of claim 9, wherein the finger activation circuit further comprises:

a monitor circuit configured to detect the minimum degradation by determining an amount of time that the first finger of the multi-fingered device is active.

11. The multi-fingered device of claim 10, wherein the monitor circuit is configured to compare a count of a number of clock cycles that the first finger of the multi-fingered device is active to a degradation threshold, and, responsive to the count being greater than or equal to the degradation threshold, instruct the control circuit to activate the second finger.

12. The multi-fingered device of claim 9, wherein the finger activation circuit further comprises:

a monitor circuit configured to detect the minimum degradation by measuring an operational parameter of the multi-fingered device in the field, compare the operational parameter to a degradation threshold, and, responsive to determining that the operational parameter meets the degradation threshold, instruct the control circuit to activate the second finger.

13. The multi-fingered device of claim 12, wherein the operational parameter is a threshold voltage of the multi-fingered device and the degradation threshold specifies a level of threshold voltage that is greater than a reference level of threshold voltage.

14. The multi-fingered device of claim 12, wherein the operational parameter is a drain saturation current of the multi-fingered device and the degradation threshold specifies a level of drain saturation current that is less than a reference level of drain saturation current.

15. The multi-fingered device of claim 9, wherein a gate of the second finger is coupled to a supply voltage potential of the integrated circuit when not active.

16. A system configured for implementation within an integrated circuit, the system comprising:

a multi-fingered device comprising a first finger configured to remain active and a second finger initially configured to be inactive concurrent with the first finger being active;

a switch coupled to a gate of the second finger, wherein the switch is configured to activate the second finger by coupling a gate of the second finger to a signal also coupled to a gate of the first finger and deactivate the second finger by decoupling the gate of the second finger from the signal; and

a finger activation circuit configured to instruct the switch to activate the second finger responsive to detecting a minimum amount of degradation in the device.

17. The system of claim 16, wherein the switch couples the gate of the second finger to a supply voltage of the integrated circuit when not active.

18. The system of claim 17, wherein the finger activation circuit comprises:

a control circuit coupled to the switch, wherein the control circuit is configured to provide a control signal to the switch; and

a monitor circuit configured to detect the minimum degradation in the device and, in response, signal the control circuit.