REMOTE BIST FOR HIGH SPEED TEST AND REDUNDANCY CALCULATION

• US 20080215937A1
• Filed: 04/04/2008
• Published: 09/04/2008
• Est. Priority Date: 01/29/2004
• Status: Active Grant

• Current Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Gorman, Kevin W., Dreibelbis, Jeffrey H., Nelms, Michael R.
• Granted Patent: US 7,472,325 B2
• Time in Patent Office: Days
• US Class Current: 714/718
• CPC Class Codes: G01R 31/31724 Test controller, e.g. BIST state machine for scan test G01R31/318555
• CPC Class Codes: G01R 31/3187 Built-in tests
• CPC Class Codes: G11C 2029/0401 in embedded memories
• CPC Class Codes: G11C 29/14 Implementation of control logic, e.g. test mode decoders
• CPC Class Codes: G11C 29/16 using microprogrammed units, e.g. state machines
• CPC Class Codes: G11C 29/44 Indication or identification of errors, e.g. for repair
• CPC Class Codes: G11C 29/4401 for self repair
• CPC Class Codes: G11C 29/72 with optimized replacement algorithms

Abstract

Disclosed in a hybrid built-in self test (BIST) architecture for embedded memory arrays that segments BIST functionality into remote lower-speed executable instructions and local higher-speed executable instructions. A standalone BIST logic controller operates at a lower frequency and communicates with a plurality of embedded memory arrays using a BIST instruction set. A block of higher-speed test logic is incorporated into each embedded memory array under test and locally processes BIST instructions received from the standalone BIST logic controller at a higher frequency. The higher-speed test logic includes a multiplier for increasing the frequency of the BIST instructions from the lower frequency to the higher frequency. The standalone BIST logic controller enables a plurality of higher-speed test logic structures in a plurality of embedded memory arrays.

Claims

1. A method of testing embedded memory arrays in functional circuitry within an integrated circuit using a built-in self test (BIST) architecture, said method comprising:

performing, by a BIST logic controller, test functions common to all of said embedded memory arrays said BIST logic controller being remote from said embedded memory arrays and operating at a lower frequency than said embedded memory arrays;

sending, by said BIST logic controller, instructions to a plurality of blocks of test logic,

each one of said blocks being incorporated into a corresponding one of said embedded memory arrays and operating at a same frequency as said corresponding one of said embedded memory array, said same frequency comprising a higher frequency relative to said lower frequency of said BIST logic controller; and

performing, by said each one of said blocks, test functions unique to said corresponding one of said embedded memory arrays, said performing comprising;

increasing the frequency of said instructions to said higher frequency.

2. The method in claim 1, all the limitations of which are incorporated herein by reference, said sending comprising using a bus connecting said BIST logic controller to said blocks of test logic so as to allow communication of said instructions from said BIST logic controller to said blocks, wherein said bus operates at said lower frequency of said BIST logic controller.

3. The method in claim 1, all the limitations of which are incorporated herein by reference, said performing, by said each one of said blocks, comprising:

performing redundancy allocation;

performing data address control generation; and

decoding each of said instructions received from said BIST logic controller into individual micro-instructions that are tailored to said corresponding one of said embedded memory arrays.

4. The method in claim 3, all the limitations of which are incorporated herein by reference, said performing of data address control generation and said performing of said redundancy allocation being based on said individual micro-instructions.

5. The method in claim 1, all the limitations of which are incorporated herein by reference, said performing by said BIST logic controller of said test functions common to all of said embedded memory arrays and said performing by said each of said blocks of said test functions unique to said corresponding one of said embedded memory arrays enabling in parallel testing of at least one of the following:

different types of embedded memories, said different types comprising at least one of a dynamic random access memory (DRAM) array, a static random access memory (SRAM) array, and a content-addressable memory (CAM) array;

memory arrays operating at different frequencies; and

different size memory arrays.

6. The method in claim 1, all the limitations of which are incorporated herein by reference, further comprising storing said instructions in one of read only memories (ROMs), a scannable read only memory (SROM), and other type of memory in said BIST logic controller.

7. The method in claim 1, all the limitations of which are incorporated herein by reference, said performing by said BIST logic controller of said test functions common to all of said embedded memory arrays comprising performing:

branch prediction;

program counter management;

utility counting; and

general BIST operation control and diagnostic outputs.

8. A method of testing embedded memory arrays in functional circuitry within an integrated circuit using a built-in self test (BIST) architecture, said method comprising:

performing, by a BIST logic controller, test functions common to all of said embedded memory arrays,

said BIST logic controller being separate from said embedded memory arrays and operating at a lower frequency than said embedded memory arrays;

sending, by said BIST logic controller, instructions a plurality of blocks of test logic,

said sending comprising using a bus connecting said BIST logic controller to said blocks of test logic so as to allow communication from said BIST logic controller to said blocks,

said bus operating at said lower frequency of said BIST logic controller,

each one of said blocks being incorporated into a corresponding one of said embedded memory arrays and operating at a same frequency as said corresponding one of said embedded memory arrays,

said same frequency comprising a higher frequency relative to said lower frequency of said BIST logic controller and said bus; and

performing, by each of said blocks, test functions unique to said corresponding one of said embedded memory arrays, said performing comprising;

increasing the frequency of said instructions to said higher frequency.

9. The method in claim 8, all the limitations of which are incorporated herein by reference, said performing, by each of said blocks, comprising:

performing redundancy allocation;

performing data address control generation; and

decoding each of said instructions received from said BIST logic controller into individual micro-instructions that are tailored to said corresponding one of said embedded memory arrays.

10. The method in claim 9, all the limitations of which are incorporated herein by reference, said performing of data address control generation and said performing of said redundancy allocation being based on said individual micro-instructions.

11. The method in claim 8, all the limitations of which are incorporated herein by reference, said performing by said BIST logic controller of said test functions common to all of said embedded memory arrays and said performing by said each of said blocks of said test functions unique to said corresponding one of said embedded memory arrays enable in parallel testing of at least one of the following:

different types of embedded memories, said different types comprising at least one of a dynamic random access memory (DRAM) array, a static random access memory (SRAM) array, and a content-addressable memory (CAM) array;

memory arrays operating at different frequencies; and

different size memory arrays.

12. The method in claim 8, all the limitations of which are incorporated herein by reference, further comprising storing said instructions in one of read only memories (ROMs), a scannable read only memory (SROM), and other type of memory in said BIST logic controller.

13. The method in claim 8, all the limitations of which are incorporated herein by reference, said performing by said BIST logic controller of said test functions common to all of said embedded memory arrays comprising performing:

branch prediction;

program counter management;

utility counting; and

general BIST operation control and diagnostic outputs.