Utilizing multiple test bitstreams to avoid localized defects in partially defective programmable integrated circuits

• US 7,849,435 B1
• Filed: 07/29/2008
• Issued: 12/07/2010
• Est. Priority Date: 10/01/2004
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Trimberger, Stephen M.
• Primary Examiner(s): Levin; Naum B
• Application Number:
  US12/181,344
• Time in Patent Office: 861 Days
• Field of Search: 716 16- 17, 714/725
• US Class Current: 716/136
• CPC Class Codes: G01R 31/318516 Test of programmable logic devices [PLDs]

Abstract

Methods and structures utilizing multiple configuration bitstreams to program integrated circuits (ICs) such as programmable logic devices, thereby enabling the utilization of partially defective ICs. A user design is implemented two or more times, preferably utilizing different programmable resources as much as possible in each configuration bitstream. The resulting user configuration bitstreams are stored along with associated test bitstreams in a memory device, e.g., a programmable read-only memory (PROM). Under the control of a configuration control circuit or device, the test bitstreams are loaded into a partially defective IC and tested using an automated testing procedure. When a test bitstream is found that enables the associated user design to function correctly in the programmed IC, i.e., that avoids the defective programmable resources in the IC, the associated user bitstream is loaded into the IC, the configuration procedure terminates, and the programmed IC begins to function according to the user design.

Claims

1. A system, comprising:

an integrated circuit (IC) comprising a plurality of programmable resources, a configuration port coupled to the programmable resources, and a configuration control circuit coupled to the programmable resources and to the configuration port; and

a memory device coupled to the configuration port of the IC, the memory device comprising at least one test configuration bitstream and a plurality of associated user configuration bitstreams, wherein;

each user configuration bitstream implements a functionally equivalent design in the IC,

each user configuration bitstream utilizes a different set of the programmable resources, and

each test configuration bitstream is configured and arranged to facilitate testing those of the programmable resources utilized by the associated user configuration bitstreams.

2. The system of claim 1, wherein each of the at least one test configuration bitstreams is associated with more than one of the user configuration bitstreams.

3. The system of claim 1, wherein the at least one test configuration bitstream comprises a plurality of test configuration bitstreams, and at least one of the user configuration bitstreams is associated with more than one of the test configuration bitstreams.

4. The system of claim 1, wherein at least one of the programmable resources in the IC is included in at least two of the sets of programmable resources.

5. The system of claim 1, wherein each of the programmable resources in the IC is excluded from at least one of the sets of programmable resources.

6. The system of claim 1, wherein each of the user configuration bitstreams includes at least one common set of the programmable resources, and wherein logic implemented by the common set is implemented in the design using triple modular redundancy.

7. The system of claim 1, wherein each user configuration bitstream enables the design to meet a common set of predetermined timing constraints when programmed into a fully functional IC.

8. The system of claim 1, wherein the memory device further comprises a plurality of test data values, each test data value being associated with one of the test configuration bitstreams.

9. The system of claim 8, wherein each test data value comprises a value expected from an automated testing procedure when applied to a fully functional IC programmed with an associated test configuration bitstream.

10. The system of claim 8, wherein the test data values comprise checksum values.

11. The system of claim 1, wherein the system comprises an IC package enclosing the IC and the memory device.

12. The system of claim 1, wherein the memory device comprises a programmable read-only memory (PROM).

13. The system of claim 1, wherein the memory device comprises a computer-readable medium.

14. The system of claim 1, wherein the IC comprises a programmable logic device (PLD).

15. The system of claim 14, wherein the PLD comprises a field programmable gate array (FPGA).

16. The system of claim 1, wherein the IC comprises a partially defective IC.

17. The system of claim 1, wherein at least one of the test configuration bitstreams is a partial configuration bitstream.

18. The system of claim 1, wherein at least one of the user configuration bitstreams is a partial configuration bitstream.

19. The system of claim 1, wherein the memory device further comprises instructions readable by the configuration control circuit.