Method, circuit and apparatus for preserving and/or correcting product engineering information

• US 6,442,727 B1
• Filed: 10/31/2000
• Issued: 08/27/2002
• Est. Priority Date: 11/20/1997
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Jones, Christopher W.
• Primary Examiner(s): Ton, David
• Application Number:
  US09/703,283
• Time in Patent Office: 665 Days
• Field of Search: 714/755, 714/820, 714/718, 714/719, 714/6, 714/724, 714/766, 714/797, 380/30, 294/070.5, 360/53, 365/103, 365/201, 700/121
• US Class Current: 714/766
• CPC Class Codes: G06F 11/006 Identification G06F11/2289 takes precedence
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/183 by voting, the voting not being performed by the redundant components
• CPC Class Codes: G06F 11/2635 using a storage for the test inputs, e.g. test ROM, script files

Abstract

A method, circuit and apparatus is provided for preserving and/or correcting product engineering information. Non-volatile storage devices reserved for receiving product engineering bits can either be contained in at least three separate storage locations spaced from each other across the integrated circuit or, alternatively, be contained in a single storage location area with error correction bits and/or words added to that location. In the first instance, redundant product engineering bits are written to each storage location. Product engineering bits read from a majority of those locations which have identical values are deemed valid. The addition of extra bits and/or words can be combined with the possibly defective product engineering bits to correct errors in those bits. Using redundancy to correct errors caused by charge loss or charge gain within previously stored product engineering values proves a beneficial outcome since testing the product engineering bit locations is not necessarily a viable solution. The product engineering bit locations may be programmed well before test patterns can be written to and read from those locations. Further, the uniquely programmed product engineering bits may unduly be lost during normal assembly of die into an integrated circuit package.

Claims

1. An integrated circuit, comprising:

at least three non-volatile storage locations spaced from each other across at least a portion of the integrated circuit, wherein each of said storage locations is adapted to receive identical information; and

a circuit adapted to indicate correct information read from said storage locations when the identical information is read from a majority of said storage locations.

2. The integrated circuit as recited in claim 1, wherein said information is unique to tracing the integrated circuit to a plurality of parameters associated with manufacturing and testing the integrated circuit.

3. The integrated circuit as recited in claim 1, wherein each of said storage locations has a separate address within a first address space inaccessible during normal operation of the integrated circuit.

4. The integrated circuit as recited in claim 1, wherein said information is programmed during manufacture of the integrated circuit, and wherein the programmed information is electrically read during test of the integrated circuit to determine a parameter associated with manufacturing the integrated circuit.

5. The integrated circuit as recited in claim 1, wherein said information is programmed during a first test of the integrated circuit, and wherein the programmed information is electrically read during a second test subsequent to the first test to determine a parameter under which the integrated circuit was tested during the first test to determine the extent of test result skewing between the first and second test.

6. The integrated circuit as recited in claim 1, wherein the information is unique to tracing the integrated circuit to a plurality of parameters associated with programming the integrated circuit.

7. A storage location formed upon an integrated circuit, said storage location comprising:

a first set of bit locations adapted to store information; and

a second set of bit locations adapted to determine corruption of said first set of bit locations, wherein at least the second set of bit locations is inaccessible during normal operation of the integrated circuit.

8. The storage location as recited in claim 7, wherein the information is associated with manufacture and test of the integrated circuit.

9. The storage location as recited in claim 7, wherein said second set of bit locations is adapted to detect and correct digital values read from said first set of bit locations.

10. The storage location as recited in claim 7, wherein said information is programmed during manufacture of the integrated circuit, and wherein the programmed information is electrically read during test of the integrated circuit to trace the integrated circuit to a particular manufacturing process.

11. The storage device as recited in claim 7, wherein said information is programmed during a first test of the integrated circuit, and wherein the programmed information is electrically read during a second test subsequent to the first test to determine the extent of test result skewing between the first and second test.

12. The storage device as recited in claim 7, wherein said first set of bit locations is further adapted to receive information for tracing the integrated circuit to a plurality of parameters associated with programming the integrated circuit.

13. A method, comprising:

programming a first set of bit locations with information while programming a second set of bit locations with error correction bits, wherein at least the second set of bit locations is inaccessible during normal operation of an integrated circuit; and

reading the programmed information and the programmed error correction bits, wherein said error correction bits are adapted to detect and correct erroneous programmed information.

14. The method as recited in claim 13, further comprising fabricating a structure on said integrated circuit or testing the integrated circuit, wherein said programming is performed before, during or after said fabricating or said testing.

15. The method as recited in claim 13, further comprising reading the programmed error correction bits to detect and correct erroneous programmed information.